Show HN: I made a free app to calibrate your turntable by simply playing a song(grooved.okat.best)
grooved.okat.best
Show HN: I made a free app to calibrate your turntable by simply playing a song
https://grooved.okat.best/
238 comments
Just put a record on yesterday and my wife said it was playing too fast. I thought she was wrong, then I see this post today! I grabbed the app and gave it a go, 3.5% too fast according to your app. Now I have to figure out how to adjust the damn thing. Really appreciate a free nonsense free app.
update: youtube to the rescue. pretty common affordable turntable( Audio-Technica LP60), so I figure I would put the vid link here for others who might want to know - https://www.youtube.com/watch?v=d3PdS2V8Jz0
update: youtube to the rescue. pretty common affordable turntable( Audio-Technica LP60), so I figure I would put the vid link here for others who might want to know - https://www.youtube.com/watch?v=d3PdS2V8Jz0
3.5% is a lot! One semitone is a bit shy of 6 percent.s
It's between 59 and 60 cents: more than a quarter semitone.
Exact value:
It's between 59 and 60 cents: more than a quarter semitone.
Exact value:
1> (* 1200 (log2 1.035))
59.5569212695205
So many recordings (especially before 2000) seem to be sped up a little. I can’t tell by listening to the song but when you try to play along with a guitar, it sounds terrible. Sometimes it helps to find a live version on YouTube.
Correct. That was often done when mastering with tape. Record at one speed, playback at another to make it sound more "lively." There are songs that were sped up that way anywhere from 25 to 40 cents. It's another reason why live music so often doesn't sound like the recording.
When using digital mastering, you can also adjust the playback speed, but you can correct the shift. You get more "liveliness" without the shift change. That's why you're not hearing the pitch shift so much in more recent music.
When using digital mastering, you can also adjust the playback speed, but you can correct the shift. You get more "liveliness" without the shift change. That's why you're not hearing the pitch shift so much in more recent music.
A bunch of the High Voltage-era AC/DC stuff was this way, IIRC. It's really awkward to play guitar along with the songs in question unless you painstakingly match the goofy tuning of the song, or adjust the pitch of the song first.
I could swear the music video version of Evil by Interpol is faster than the album version, but it’s just inconvenient enough to verify that I haven’t bothered
comparing runtimes should do
Do you happen to know of any tools for fixing pitch issues in music files?
I used Audacity recently to fix some youtuber's backing track for guitar improv, by tuning down 7 cents. I reuploaded it:
https://www.youtube.com/watch?v=TE3pgOkfYu0
In that case, it's a pure stretch: i.e. the tempo is slowed down by a factor of 0.996 to achieve the pitch change.
I also have an unpublished version of that track transposed from the key of Em to Dm; that was a pitch change preserving tempo.
https://www.youtube.com/watch?v=TE3pgOkfYu0
In that case, it's a pure stretch: i.e. the tempo is slowed down by a factor of 0.996 to achieve the pitch change.
I also have an unpublished version of that track transposed from the key of Em to Dm; that was a pitch change preserving tempo.
How did you determine 7 cents was the correct amount?
Trial and error. Guitar meticulously tuned to concert pitch, with attention to the 12-15 fret area, then compare against versions of the track slowed down by all available factors in audacity from around 0.993 to 0.998. (The stretch tool doesn't take more digits, stupidly.)
"Guitar meticulously tuned to concert pitch, with attention to the 12-15 fret area"
When you need to pay attention to anything outside of open string, fretted 12th, open harmonic 12th fret (and fretted 24th if you have a 24+ fret guitar) for intonation, it's time to get the guitar to a luthier for setup maintenance. Something else is drastically wrong in the setup.
When you need to pay attention to anything outside of open string, fretted 12th, open harmonic 12th fret (and fretted 24th if you have a 24+ fret guitar) for intonation, it's time to get the guitar to a luthier for setup maintenance. Something else is drastically wrong in the setup.
When you're deciding between a 6, 7 and 8 cent pitch shift, using your instrument as a reference, you should pay attention to the notes you are using, no matter how confident you are in the intonation.
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Depends on what you're trying to do. For guitar practice, I use AnyTune Pro+. I use for learning the lead, because with my musical experience I can nail the rhythm guitar part by ear in a couple minutes. Not so with lead guitar parts, I'm afraid! But yeah, you can adjust frequency, you can adjust playback speed, you can pick a point A and a point B and loop between those points (great for breaking down each section of the solo). If you slow the playback speed slower than 70% or so, you're going to start getting a lot of digital noise. Once you've learned how to hear the notes through the noise then you can learn even super fast solos.
As I'm writing this I'm thinking to myself I know there are AI tools now that can take any track and produce all the stems for all the different parts in the track. You'd think for something like the lead guitar they could analyze that stem and produce either the tablature or standard music notation for the solo. That would be kinda awesome! I wonder if such a tool now exists?
As I'm writing this I'm thinking to myself I know there are AI tools now that can take any track and produce all the stems for all the different parts in the track. You'd think for something like the lead guitar they could analyze that stem and produce either the tablature or standard music notation for the solo. That would be kinda awesome! I wonder if such a tool now exists?
I wrote elsewhere that I recently asked Claude AI to help me learn a Pixies song on guitar and it wouldn't give me anything but generic advice because of copyright.
Audacity.
Free and open-source.
Free and open-source.
Anatares Auto-tune.
What are cents in the context of playback speed? Hundredths of an RPM?
A cent is a factor of 2^(1/1200). There are 1200 cents in an octave, which is a doubling in frequency: if we have 1200 of them, 2^(1200/1200) = 2^1 = 2.
Lisp-wise:
Lisp-wise:
2> (exp2 (/ 1200)) ;; exp2 is courtesy of ISO C 99
1.00057778950655
A little more intuitively, 1 semitone is one "note", aka the interval between two successive notes on a piano (including white and black keys) such as C to C#, and to talk about intervals less than that, we use cents as 1/100 of a semitone.
Musically, two notes an octave apart vary by a factor of 2 (e.g. Middle A (A4) is 440Hz and the next A (A5) is 880Hz), and our ears hear frequencies logarithmically rather than linearly, so each of the 12 semitones in an octave is a factor of 2^(1/12) higher than the previous one (so that 12 of them in a row result in doubling the frequency), and therefore the 100 cents between each semitone are each (2^(1/12))^100 = 2^(1/1200) greater than the previous one.
Musically, two notes an octave apart vary by a factor of 2 (e.g. Middle A (A4) is 440Hz and the next A (A5) is 880Hz), and our ears hear frequencies logarithmically rather than linearly, so each of the 12 semitones in an octave is a factor of 2^(1/12) higher than the previous one (so that 12 of them in a row result in doubling the frequency), and therefore the 100 cents between each semitone are each (2^(1/12))^100 = 2^(1/1200) greater than the previous one.
There are 100 cents to a semitone - by definition. The frequency shift of a 25 to 40 cent adjustment isn't likely going to be noticed by the average listener. A lot of times you don't notice it until you try to play guitar along with the song and you notice something is a little "off."
In can drive you nuts when you're playing by ear because when trying to find the root note, i.e. the key, you'll find it between two semitones. Always go for the lower tone. For example, if it sounds like it's a little sharper than A, but it's definitely not Bb, then you know it was A and the mastering was sped up. That's another thing, in my experience it's always sped up and never slowed down.
I have a theory that one of the reasons Eb standard guitar tuning started becoming so popular in the late 60s and into the 70s was because the speed up was getting to be so common that guitar players started adjusting their tuning for it, not to mention you generally get a "heavier" sound.
In can drive you nuts when you're playing by ear because when trying to find the root note, i.e. the key, you'll find it between two semitones. Always go for the lower tone. For example, if it sounds like it's a little sharper than A, but it's definitely not Bb, then you know it was A and the mastering was sped up. That's another thing, in my experience it's always sped up and never slowed down.
I have a theory that one of the reasons Eb standard guitar tuning started becoming so popular in the late 60s and into the 70s was because the speed up was getting to be so common that guitar players started adjusting their tuning for it, not to mention you generally get a "heavier" sound.
Hey that's awesome to hear, thanks for trying it out!
This is exactly what I hoped for when building this app. Making a dead simple tool for people who want their records to sound better, but may not have the equipment or knowledge necessary to adjust it.
This is exactly what I hoped for when building this app. Making a dead simple tool for people who want their records to sound better, but may not have the equipment or knowledge necessary to adjust it.
I'd be curious to know _why_ your wife felt it was playing too fast. Was it out of tune, out of tempo or something else?
She is musically inclined and she popped on a record I had recently gifted her of one of her favorite bands. She was in marching band her entire high school experience as well. She always finds stuff like this. She recognizes when it’s a different recording or not the “proper version” from her childhood. It all sounds fine to me! As a visual person, the finer understandings of music might as well be magic to me.
You can try with my example video above! Listen to the first couple seconds of the song on my recording (skip to 0:08):
https://twitter.com/OKatBest/status/1795453042994680148
Then listen to the original:
https://www.youtube.com/watch?v=9NplyW8TF18
Maybe it's just me, but as soon as the guitar starts I can tell it's way too high pitched.
https://twitter.com/OKatBest/status/1795453042994680148
Then listen to the original:
https://www.youtube.com/watch?v=9NplyW8TF18
Maybe it's just me, but as soon as the guitar starts I can tell it's way too high pitched.
If it’s a song you know well it’s certainly possible. It just sounds wrong. I once pegged a friends turntable as well sharp (and it was) in just a few seconds.
When US (NTSC) shows are aired in Europe (PAL), the framerate difference necessitates a small speed-up. It's barely noticeable, except when music is playing, at which point it is very, very noticeable. Yes, it's a little higher pitched, but it just feels wrong and is immediately noticeable. I think it's about 3% speed up, which is exactly what's being described here.
NTSC is 29.97 fps and PAL is 25. That’s almost 20%!
They may have been referring to film (24 FPS) or its broadcast equivalent (23.976 FPS) being shifted to PAL, which is quite a bit smaller of a jump.
NTSC —> PAL can either be annoying, or difficult to manage without artifacts. If the NTSC source is telecined from a 23.976 source, you can invert that process to get the original back, and then deal with the minor time shift to PAL. If it’s pure NTSC, there’s a lot of filtering to be done to get an acceptable result. At least, last I played with it.
NTSC —> PAL can either be annoying, or difficult to manage without artifacts. If the NTSC source is telecined from a 23.976 source, you can invert that process to get the original back, and then deal with the minor time shift to PAL. If it’s pure NTSC, there’s a lot of filtering to be done to get an acceptable result. At least, last I played with it.
I believe with music it's much easier to notice that something is sped up. I'm watching videos, listening to podcasts all the time sped up, now don't even notice it, but with music, even a 10% speed up is extremely noticeable.
Wow, I'm feeling lucky. I have the exact same turntable. Using a different app (since I use Android) I was able to gyroscopicly measure just 1.3% average difference.
I have a sense of tone and it's always seemed fine to me.
I have a sense of tone and it's always seemed fine to me.
Curious. Does this turntable have the flashing lights that sync to the edge of the plate to indicate speed?
good to know about the adjustment screws. I would have tried having the turntable straddle two piles of books or some such arrangement so that I could adjust the setting in real-time from below the turntable while getting the speed display from the phone.
hey, I have the same one and didn't know about these controls! I'll definitely try this out now
> Now I have to figure out
I'm glad it didn't continue with where you'll sleep tonight :)
I'm glad it didn't continue with where you'll sleep tonight :)
This seems really clever -- kudos!
I'm curious how it actually works?
At first I assumed you were comparing the vinyl track to the reference digital track from some streaming service and either analyzing the frequencies with FFT or the timing of peaks.
But I watched your demo video and you don't need to tell it anything about the song.
Which makes me think you're rather doing an FFT and simply trying to match how well the frequencies align to the well-tempered scale based on A 440 hZ.
Which then leads me to three questions:
1) Obviously this wouldn't work if you were playing a standup comedy album or something? Or the drum solo part of a song?
2) Are essentially all albums perfectly in tune with A 440 hZ? For example with classical music, I understand that 442 is also used, baroque is sometimes at 415, and 432 has been common as well? I don't know about pop but I can't help but wonder if some artists have intentionally chosen something other than 440 over the decades.
3) I assume this won't work if the turntable speed is off by more than 2.8%? Since the distance from A4 (440 hZ) to A-flat-4 (415.30 hZ) is a decrease of 5.6%, and so if the turntable is off by more than half of that you'd be trying to align to the wrong note?
I'm curious how it actually works?
At first I assumed you were comparing the vinyl track to the reference digital track from some streaming service and either analyzing the frequencies with FFT or the timing of peaks.
But I watched your demo video and you don't need to tell it anything about the song.
Which makes me think you're rather doing an FFT and simply trying to match how well the frequencies align to the well-tempered scale based on A 440 hZ.
Which then leads me to three questions:
1) Obviously this wouldn't work if you were playing a standup comedy album or something? Or the drum solo part of a song?
2) Are essentially all albums perfectly in tune with A 440 hZ? For example with classical music, I understand that 442 is also used, baroque is sometimes at 415, and 432 has been common as well? I don't know about pop but I can't help but wonder if some artists have intentionally chosen something other than 440 over the decades.
3) I assume this won't work if the turntable speed is off by more than 2.8%? Since the distance from A4 (440 hZ) to A-flat-4 (415.30 hZ) is a decrease of 5.6%, and so if the turntable is off by more than half of that you'd be trying to align to the wrong note?
> Are essentially all albums perfectly in tune with A 440 hZ? For example with classical music, I understand that 442 is also used, baroque is sometimes at 415, and 432 has been common as well? I don't know about pop but I can't help but wonder if some artists have intentionally chosen something other than 440 over the decades.
No they are not all tuned to 440Hz. This is really evident if you play an instrument and want to play along with an album.
No they are not all tuned to 440Hz. This is really evident if you play an instrument and want to play along with an album.
Every. Rolling. Stones. Album.
It probably doesn't need to do an FFT, it just need to be able to count beats and have a database of BPM values for popular songs. You could use something like AcoustID/Chromaprint to identify the song you're playing.
A very simple idea, as all the best ideas are.
A very simple idea, as all the best ideas are.
I would expect:
1. Detect wow: https://www.youtube.com/watch?v=kCwRdrFtJuE
2. Time wow.
3. Round to nearest record speed and report delta.
I'd also expect that armed with a normal FFT algorithm that Ye Olde Bash On Algorithme Until Functionale would be fairly likely to work with reasonable effort, without having to get too "signal processor-y" on the FFT output.
1. Detect wow: https://www.youtube.com/watch?v=kCwRdrFtJuE
2. Time wow.
3. Round to nearest record speed and report delta.
I'd also expect that armed with a normal FFT algorithm that Ye Olde Bash On Algorithme Until Functionale would be fairly likely to work with reasonable effort, without having to get too "signal processor-y" on the FFT output.
Wow is wavering speed. A constant turntable speed error (that this helps you calibrate out) doesn't produce wow.
All turntables have wow. Wow is determined by the rotational speed. So if you measure 33.2326 wow oscillations per minute, you can know the turn table is a touch too fast. Wow would not be used to measure the error, it would be used to measure the absolute speed. Getting the error from that point is trivial.
I don't think you could use FFT or similar to reliably measure wow to anywhere near the accuracy necessary to produce a reliable amount of correction from just a few seconds of an arbitrary LP.
If you were using an LP with a known pure 440 hZ sine wave that you could lock onto exactly, then sure. That's kind of how frequency modulation -- FM radio -- works.
But I really don't see how you could do this with songs that are full of frequencies coming in and out and changing all over the place. If you analyzed the full side of the LP, you could probably get enough signal out of that.
But trying to measure the precise wavelength of wow when you're only getting a few wavelengths' worth, from a complex signal? I don't see how.
If you were using an LP with a known pure 440 hZ sine wave that you could lock onto exactly, then sure. That's kind of how frequency modulation -- FM radio -- works.
But I really don't see how you could do this with songs that are full of frequencies coming in and out and changing all over the place. If you analyzed the full side of the LP, you could probably get enough signal out of that.
But trying to measure the precise wavelength of wow when you're only getting a few wavelengths' worth, from a complex signal? I don't see how.
I am 100% abundantly positive that signal processing code could do this, and in fact by signal processing standards it's not even particularly hard. You may need more time than the app takes, though I am inclined to think that the app doesn't exactly need a number to twelve significant digits and you could get a single-digit-percentage significant digit lock pretty quickly. Even at 33&1/3rd you only need a few seconds for three or four revolutions.
I am much less confident about my claims that it is something you could bash together in "normal code" from an FFT, without advanced math, but it still seems likely to me. You have huge stonking correlations between the frequencies you can exploit. Imagine a normal FFT chart like you've seen any number of times. Now, take that same thing and wave it up and down quite visibly on a sine wave. Nice and big in your imagination so you can see it. You think that's not something that could be picked up? Now, scaling it down to where you can't hear it anymore may make it harder to believe, but the same code will pick it up. To a computer it would still be clear as day. This is one of those things microphones pick up much, much better than human ears, just like microphones trivially pick up a quite 1001Hz tone next to a loud 1000Hz tone even though we can't hear it at all.
Compared to, say, recognizing a voice and extracting words from it, this is pretty trivial stuff.
I am much less confident about my claims that it is something you could bash together in "normal code" from an FFT, without advanced math, but it still seems likely to me. You have huge stonking correlations between the frequencies you can exploit. Imagine a normal FFT chart like you've seen any number of times. Now, take that same thing and wave it up and down quite visibly on a sine wave. Nice and big in your imagination so you can see it. You think that's not something that could be picked up? Now, scaling it down to where you can't hear it anymore may make it harder to believe, but the same code will pick it up. To a computer it would still be clear as day. This is one of those things microphones pick up much, much better than human ears, just like microphones trivially pick up a quite 1001Hz tone next to a loud 1000Hz tone even though we can't hear it at all.
Compared to, say, recognizing a voice and extracting words from it, this is pretty trivial stuff.
> Now, scaling it down to where you can't hear it anymore may make it harder to believe, but the same code will pick it up.
That's where you're wrong. FFT frequency bands are surprisingly wide. You can make them narrower but with the tradeoff of losing temporal resolution. And it gets worse the lower the frequency gets.
There is absolutely no way you're going to detect a near-0.555 hZ effect from a few seconds of audio and determine whether it's off the frequency by 0.1% or even 1%.
Like I said, sure if you're dealing with a pure sine wave. But not a complex signal using FFT.
Or to put it another way -- a 1,000 hZ signal? Absolutely. But a 0.5 hZ signal? Absolutely not.
That's where you're wrong. FFT frequency bands are surprisingly wide. You can make them narrower but with the tradeoff of losing temporal resolution. And it gets worse the lower the frequency gets.
There is absolutely no way you're going to detect a near-0.555 hZ effect from a few seconds of audio and determine whether it's off the frequency by 0.1% or even 1%.
Like I said, sure if you're dealing with a pure sine wave. But not a complex signal using FFT.
Or to put it another way -- a 1,000 hZ signal? Absolutely. But a 0.5 hZ signal? Absolutely not.
There are various DFT-based algorithms for high-precision pitch detection.
Two common algorithms are cepstrum and analysis, and auto-correlation, which involve taking the DFT or inverse DFT of the absolute value of the DFT of the signal.
Find the peaks of the result, and then fit a cubic polynomial to the the peak, and the bins on either side, and then calculate the maximum value of the polynomial. The value at the which the maximum occurs determines the inverse frequency, which can then be converted to pitch.
Both algorithms produce results that are accurate to less than 0.1 cents. You do have to tweak buffer sizes and windowing depending on what pitch ranges you are interested in, and do some post filtering to skip over transients.
The temporal resolution problem is solved by calculating the result on overlapping frames. .
Two common algorithms are cepstrum and analysis, and auto-correlation, which involve taking the DFT or inverse DFT of the absolute value of the DFT of the signal.
Find the peaks of the result, and then fit a cubic polynomial to the the peak, and the bins on either side, and then calculate the maximum value of the polynomial. The value at the which the maximum occurs determines the inverse frequency, which can then be converted to pitch.
Both algorithms produce results that are accurate to less than 0.1 cents. You do have to tweak buffer sizes and windowing depending on what pitch ranges you are interested in, and do some post filtering to skip over transients.
The temporal resolution problem is solved by calculating the result on overlapping frames. .
Sure but the problem remains: you can't do that with only a few oscillations of a weak signal against a loud noisy complex signal.
You simply can't detect an inaudible-to-human-ears 0.5 hZ signal from 3 or 5 seconds of complex normal-volume audio, down to the accuracy of cents, much less 0.1 cents.
As I said above: a 1,000 hZ signal? Absolutely. But a 0.5 hZ signal? Absolutely not. There just isn't enough signal for that level of precision. No matter what tool you're using.
You simply can't detect an inaudible-to-human-ears 0.5 hZ signal from 3 or 5 seconds of complex normal-volume audio, down to the accuracy of cents, much less 0.1 cents.
As I said above: a 1,000 hZ signal? Absolutely. But a 0.5 hZ signal? Absolutely not. There just isn't enough signal for that level of precision. No matter what tool you're using.
But you could easily detect frequency modulation of a 220Hz signal by a 0.5 Hz sin wave, which would have sidebands separated by 4 cents. This is conceptually similar to heterodyning. Wow in the source material ends up creating sidebands of the source material in a frequency range that is more amenable to signal analysis. Whether this works or not depends on how much wow an actually record player has. But a back-of-the-envelope calculation seems to suggest that very tiny amounts of wow should create detectable side-bands.
My suspicion is that OP assumed that the source material was accurately tuned to A=440, which is not a safe assumption, but is probably true for any source material that has a keyboard instrument which will almost always be tuned to A=440. Calculate the reference pitch for the source material, and you can tell how much the speed of the turntable is off. (And as others have pointed out, may be completely buggered by common mastering practices, and by Original Instrument recordings of classical music using pitch references other than A=440).
But it doesn't seem implausible that you could use analysis of wow in the source signal too.
My suspicion is that OP assumed that the source material was accurately tuned to A=440, which is not a safe assumption, but is probably true for any source material that has a keyboard instrument which will almost always be tuned to A=440. Calculate the reference pitch for the source material, and you can tell how much the speed of the turntable is off. (And as others have pointed out, may be completely buggered by common mastering practices, and by Original Instrument recordings of classical music using pitch references other than A=440).
But it doesn't seem implausible that you could use analysis of wow in the source signal too.
I agree that FFT is not the easiest tool to use for the job. If I were trying to solve this problem, I'd use autocorrelation.
But it still sounds very challenging: there's multiple sources of periodic frequency change both in recordings and in playback mechanisms.
But it still sounds very challenging: there's multiple sources of periodic frequency change both in recordings and in playback mechanisms.
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Maybe the distortion in the physical disk has some type of signature, and it can be determined whether that distortion is fast or slow.
For ex, I would bet that 2x intended speed isn’t simply 2x every frequency in the FFT, when played through vinyl on a physical turntable.
Maybe some collection of distortion signals based on disk manufacturing and turntable manufacturing.
For ex, I would bet that 2x intended speed isn’t simply 2x every frequency in the FFT, when played through vinyl on a physical turntable.
Maybe some collection of distortion signals based on disk manufacturing and turntable manufacturing.
I understand what you're saying better, but I don't think you're going to be able to autocorrelate the frequency variation precisely at all from a few revolutions, especially since there are other non-periodic sources of frequency variability.
It does if the hole in the record is not exactly in the center.
If you play an orchestra with an organ the organ sets the reference point. 440 Hz is a relatively young standard, many organs were built before that.
Thank you so much! I spoke about why I'm not flat out saying how it works in another comment but let me answer your questions:
1) It actually might! Worth a shot I guess, but I don't have any comedy albums to try it out. I was able to get drum solos working fine
2) Was answered better by somebody else
3) I was able to get it to detect speed issues up to 9% off, beyond that it just stops working completely. Though that was in controlled environment so YMMV. If you see the sample vid I posted above, my player is roughly 4% off which is a lot but I genuinely believe a whole lot of people wouldn't notice that
1) It actually might! Worth a shot I guess, but I don't have any comedy albums to try it out. I was able to get drum solos working fine
2) Was answered better by somebody else
3) I was able to get it to detect speed issues up to 9% off, beyond that it just stops working completely. Though that was in controlled environment so YMMV. If you see the sample vid I posted above, my player is roughly 4% off which is a lot but I genuinely believe a whole lot of people wouldn't notice that
This is pretty cool, thanks for sharing it.
Is this the aforementioned comment about _why_ you aren't being specific about the implementation?
> Eventually I decided to see if I could find a novel, more user-friendly approach that doesn't require you to put a thousand-dollars phone on a fast moving spinning thingie, and that's how Grooved came to be.
If it isn't then I couldn't find it. I was very curious about that too (both how it worked, and then the incentive for secrecy--totally your prerogative but again curious given the veiled-to-me explanation) but didn't seem to find such a comment. Protecting novelty seems like the implied reason.
Is this the aforementioned comment about _why_ you aren't being specific about the implementation?
> Eventually I decided to see if I could find a novel, more user-friendly approach that doesn't require you to put a thousand-dollars phone on a fast moving spinning thingie, and that's how Grooved came to be.
If it isn't then I couldn't find it. I was very curious about that too (both how it worked, and then the incentive for secrecy--totally your prerogative but again curious given the veiled-to-me explanation) but didn't seem to find such a comment. Protecting novelty seems like the implied reason.
Here's the comment: https://news.ycombinator.com/item?id=40502383
Essentially I don't want to have somebody swoop in, replicate the same thing, be better at marketing, and charge money for it. I'm both protecting users because they shouldn't be charged for something that is free, but also protecting my ego because I spent time and effort and as far as I can tell I'm the first one to build an app that works this way and it sucks when somebody takes a community thing and paywalls it.
Once the Android version is out and everything blows over I might consider making the apps open-source so that anyone can see and learn how it works, then potentially make derivative works.
Essentially I don't want to have somebody swoop in, replicate the same thing, be better at marketing, and charge money for it. I'm both protecting users because they shouldn't be charged for something that is free, but also protecting my ego because I spent time and effort and as far as I can tell I'm the first one to build an app that works this way and it sucks when somebody takes a community thing and paywalls it.
Once the Android version is out and everything blows over I might consider making the apps open-source so that anyone can see and learn how it works, then potentially make derivative works.
That makes sense and seems like a justified concern. Sorry for what you experienced with Boop. And thanks for the reply and direction to the comment, I overlooked it.
Usually when an app comes out on iPhone but not Android the excuse is that "Android users don't pay for apps so it wasn't a priority", despite it being way more difficult and a bit more expensive to develop for iPhone over Android.
But in your case you don't plan on monetizing, so why iPhone first?
But in your case you don't plan on monetizing, so why iPhone first?
Well I have been developing native apps for both for over a decade, and I don't think either is particularly more difficult than the other.
What it came down to is that I use an iPhone as my daily driver, and when I pulled my Android test device out of a drawer the battery was twice the size so I immediately brought it to an electronics recycling center.
Which means that in order to complete the Android version, I need to shell out $400 for a new phone I'm only gonna use once for a non-commercial project. So my idea was, let's release iOS first, see if people care, and then I'll spend the remaining time and money to finish up the Android build!
I think if I did try to finish Android at the same time, I would have given up on both and released nothing.
What it came down to is that I use an iPhone as my daily driver, and when I pulled my Android test device out of a drawer the battery was twice the size so I immediately brought it to an electronics recycling center.
Which means that in order to complete the Android version, I need to shell out $400 for a new phone I'm only gonna use once for a non-commercial project. So my idea was, let's release iOS first, see if people care, and then I'll spend the remaining time and money to finish up the Android build!
I think if I did try to finish Android at the same time, I would have given up on both and released nothing.
Makes sense to develop for what you use yourself.
I've developed for both as well and would say getting _started_ with iOS development is about 10x more time consuming and complicated than Android -- or at least it was about 8 years ago.
I know you know this, but you don't need to own an Android phone to develop for Android (and you don't have to spend anywhere near $400 on one if you do want one).
Looks like it'll be a pretty great app and hope you do manage to get the Android version up and running.
I've developed for both as well and would say getting _started_ with iOS development is about 10x more time consuming and complicated than Android -- or at least it was about 8 years ago.
I know you know this, but you don't need to own an Android phone to develop for Android (and you don't have to spend anywhere near $400 on one if you do want one).
Looks like it'll be a pretty great app and hope you do manage to get the Android version up and running.
Mostly likely, they have an iPhone and this is for a need they had, so they developed it to solve their own need first.
I appreciate the fact that they're developing an Android version at all, because this sounds simple and useful for me!
I appreciate the fact that they're developing an Android version at all, because this sounds simple and useful for me!
My first thought was that it is listening to the scratches rather than the music, but I guess they speed up as the record gets played and the arm moves inwards. So, my second guess is that it's listening to the pitch of the notes being played. Of course, old albums (especially punk albums) are probably tuned to whatever worked on the day—maybe a tuning fork, possibly a piano, maybe just to one of the instruments.
Umm, no, scratches meet the needle once per revolution, regardless of the needle's position. So that would definitely be a possible method. But not all records have scratches, or they could be at an angle, which would give the wrong estimate. Also, actual sounds on the record could have scratch-like qualities.
>scratches meet the needle once per revolution, regardless of the needle's position
I need to go away and think about that :D
I need to go away and think about that :D
The needle doesn't pass at a constant "ground speed" everywhere on the record. On the outside the needle "travels faster" and in theory you have more detail. Near the middle the needle travels over the record surface slower.
That's one of the reasons you'd put your best song on side A, song 1 and your 2nd best song on side B, song 1 - you got the most detail on the outside track. I remember seeing an interview with Led Zeppelin quite a few years back where they were claiming they knew they'd have a smash hit with Stairway to Heaven. Which was funny, because I remembered then seeing an interview several years before where they said it was a track they never thought was going to go anywhere.
Which is it? It's track position - 4th track on the A side, i.e. the last track, tells you how important they thought it was. Which is to say, it was a "throwaway" track that made it big. It happens.
The other odd thing about that album is "When the Levee Breaks" is considered to be the 2nd-most popular song off of the album and it too was the last track on the B side.
What this tells me is the album's producer, one Jimmy Page, was out of touch with what Led Zeppelin fans liked most. Based off the sound of the next album, Houses of the Holy, I'd say Mr. Page got the message loud and clear.
Which is it? It's track position - 4th track on the A side, i.e. the last track, tells you how important they thought it was. Which is to say, it was a "throwaway" track that made it big. It happens.
The other odd thing about that album is "When the Levee Breaks" is considered to be the 2nd-most popular song off of the album and it too was the last track on the B side.
What this tells me is the album's producer, one Jimmy Page, was out of touch with what Led Zeppelin fans liked most. Based off the sound of the next album, Houses of the Holy, I'd say Mr. Page got the message loud and clear.
I’m not sure about this. Thriller (by Michael Jackson) is one of the biggest pop songs of all time. It was also the fourth track on the A side. Bohemian Rhapsody (another one of the best selling singles of all time) was the fourth track on the B side.
Those are two examples off the top of my head. If you give me a bit of time to put my kid to bed, I’m sure that I’ll find many more.
Those are two examples off the top of my head. If you give me a bit of time to put my kid to bed, I’m sure that I’ll find many more.
What you've just learned is that pop producers are not in tune with what's good. It's a hard lesson to learn.
Not really. I found data that shows that released singles aren’t necessarily placed first on a side.
As a turntable rotates at a constant RPM, scratches change in pitch (if there is such a thing) but it will always "pop" once per rotation.
My guess would be some filtering (to remove the actual music) and some kind of autocorrelation algorithm to detect some periodic patterns with a period matching the expected rotation speed of a record within a few percent (33.3 RPM, it doesn't talk about 45/78).
My guess would be some filtering (to remove the actual music) and some kind of autocorrelation algorithm to detect some periodic patterns with a period matching the expected rotation speed of a record within a few percent (33.3 RPM, it doesn't talk about 45/78).
ShazamKit, from that fetch the BPM, BPM detection from the mic, compare ?
It works offline, though.
I just tested and a song that works fine normally failed as soon as I turned Airplane Mode on.
Does it? I don't see that claim being made anywhere.
They do say that the audio is processed locally, but that does not preclude them from making an API call to find a signature match.
> The audio stream is processed locally on your device and never recorded.
They do say that the audio is processed locally, but that does not preclude them from making an API call to find a signature match.
> The audio stream is processed locally on your device and never recorded.
"Grooved does not use any third party library or API, just the built-in components provided by Apple."
ShazamKit is not third party, it is provided by Apple. Their website states "The audio stream is processed locally on your device and never recorded.", though this could refer to the audio statistics being collected locally, I assume ShazamKit still contacts an Apple API to get the classification.
You can extract pitch information and compare it to a set of quantized reference pitches as an instrument tuning app does, sure.
But you can also extract BPM info and compare that to a set of quantized reference BPMs that anyone would ever bother to use.
And also, since you’re getting multiple pitches from multiple instruments in a time series, if you can isolate particular instruments, you can calculate the key the melody and/or harmony of the song is in.
Then, you could either come up with a heuristic, or just train a Bayesian filter, using datasets of “real” and “erroneous” (key, BPM) pairs.
But you can also extract BPM info and compare that to a set of quantized reference BPMs that anyone would ever bother to use.
And also, since you’re getting multiple pitches from multiple instruments in a time series, if you can isolate particular instruments, you can calculate the key the melody and/or harmony of the song is in.
Then, you could either come up with a heuristic, or just train a Bayesian filter, using datasets of “real” and “erroneous” (key, BPM) pairs.
Are there really "standard" BPM? As far as I know, most music production is just "whatever tempo the band feels like playing." I haven't been in a recording studio, though, so maybe a use of a metronome is more common there?
In some countries there are legal and illegal BPMs, e.g. according to [0] only the BPM range from 80 to 116 is legal in Chechnya.
[0] https://www.npr.org/2024/04/09/1243632570/chechnya-music-ban...
[0] https://www.npr.org/2024/04/09/1243632570/chechnya-music-ban...
That moment when you read the first half of a sentence and know it's clearly sarcasm, and then you finish the sentence and realize it's not... :(
Adam Neely did a good video[1] showing just how silly it is.
[1] https://www.youtube.com/watch?v=Q811R6YsM0s
[1] https://www.youtube.com/watch?v=Q811R6YsM0s
I'm not in the music industry in any capacity myself, so take everything I say here with a grain of salt.
And more specifically, to address your question, I don't know enough about the recording part of music production to say whether most performers get a click-track played into their monitors or not. (I know that I've seen at least some performers using click-tracks for studio recording; but I'm not sure if that's only given if they ask for it, or if it's the studio pushing it on performer to make their jobs easier. I imagine click-tracks would always be used for multi-performer async studio recording — as otherwise you'd have performances that have conflicting BPM. But maybe not for single-performer pop/EDM songs, where it's just a vocalist laying down a track, and then everything else is done in software?)
The evidence I can cite, is from the outcome of the production process: I have a strong recollection from back in the late 2000s, of using some music library auto-tagging software that would, among other things, analyze the BPM of a song to populate the BPM ID3 field of MP3s. For at least the music I loaded into it, BPM did appear to be (mostly) quantized to nice, round numbers. (And it wasn't just the software being coarse-grained in its estimates; it did give weird numbers for unusually-produced songs.)
I do know that for any modern "produced" music (i.e. music not recorded as a live ensemble session), even if the performers did lay down their tracks at a weird BPM, the audio engineer is still going to be throwing their performances as separate tracks into a DAW. And one of the things you tell a DAW, when creating a project, is the BPM — which creates a grid of bars that tracks/samples want to snap onto. Even if you're not trimming or speed-adjusting performances so as to snap the ends of each track/sample to the DAW's grid, you're still likely snapping the beginning of each track/sample to the grid — you'd have to fight the DAW to not. Which means that, by default, if the song is "produced" enough — tracks cut up and slid around, reused, etc — then the output of this moving-and-snapping process will be a song that reads as the project's BPM.
Separately, I know that people learning to play an instrument for classical/orchestra music, often practice their instrument using a metronome (at least at the early levels.) Which perhaps gives at least some of those people the speed equivalent of perfect pitch — the ability to "lock into" certain BPMs; and to know if other performers are running fast/slow vs the "expected" BPM of the song.
I would assume that even for rock performers with no classical training, the early-level "textbook" practice for drummers and rhythm guitarists also involves playing with a metronome. It might be a lot more tenable to play a rock song at e.g. 117BPM, if everyone's just playing on the down-beat of the drums; but these performers still don't want to have a sudden, unintended shift in their BPM due to not being able to do a drum fill / complex chord change quickly enough; nor to start rushing as the song amps up, forcing everyone else into increasingly-stressful playing. In doing drills with a metronome to keep their BPM constant, these performers are likely implicitly learning to lock into certain specific BPMs as well.
My impression is that the one case where this probably isn't true, is in live jazz performance, and more specifically in live jazz improv "jam sessions." In those, the percussion (if any) isn't driving the performance, but rather is just another component of the harmony, following the (often wavering!) BPM of the lead performer.
(Is this why the classic meme of classically-trained performers not getting along with jazz artists? Because the jazz artists won't stay on beat, and this irritates some perfect-pitch-like "out of tune" feeling in the classical musician?)
And more specifically, to address your question, I don't know enough about the recording part of music production to say whether most performers get a click-track played into their monitors or not. (I know that I've seen at least some performers using click-tracks for studio recording; but I'm not sure if that's only given if they ask for it, or if it's the studio pushing it on performer to make their jobs easier. I imagine click-tracks would always be used for multi-performer async studio recording — as otherwise you'd have performances that have conflicting BPM. But maybe not for single-performer pop/EDM songs, where it's just a vocalist laying down a track, and then everything else is done in software?)
The evidence I can cite, is from the outcome of the production process: I have a strong recollection from back in the late 2000s, of using some music library auto-tagging software that would, among other things, analyze the BPM of a song to populate the BPM ID3 field of MP3s. For at least the music I loaded into it, BPM did appear to be (mostly) quantized to nice, round numbers. (And it wasn't just the software being coarse-grained in its estimates; it did give weird numbers for unusually-produced songs.)
I do know that for any modern "produced" music (i.e. music not recorded as a live ensemble session), even if the performers did lay down their tracks at a weird BPM, the audio engineer is still going to be throwing their performances as separate tracks into a DAW. And one of the things you tell a DAW, when creating a project, is the BPM — which creates a grid of bars that tracks/samples want to snap onto. Even if you're not trimming or speed-adjusting performances so as to snap the ends of each track/sample to the DAW's grid, you're still likely snapping the beginning of each track/sample to the grid — you'd have to fight the DAW to not. Which means that, by default, if the song is "produced" enough — tracks cut up and slid around, reused, etc — then the output of this moving-and-snapping process will be a song that reads as the project's BPM.
Separately, I know that people learning to play an instrument for classical/orchestra music, often practice their instrument using a metronome (at least at the early levels.) Which perhaps gives at least some of those people the speed equivalent of perfect pitch — the ability to "lock into" certain BPMs; and to know if other performers are running fast/slow vs the "expected" BPM of the song.
I would assume that even for rock performers with no classical training, the early-level "textbook" practice for drummers and rhythm guitarists also involves playing with a metronome. It might be a lot more tenable to play a rock song at e.g. 117BPM, if everyone's just playing on the down-beat of the drums; but these performers still don't want to have a sudden, unintended shift in their BPM due to not being able to do a drum fill / complex chord change quickly enough; nor to start rushing as the song amps up, forcing everyone else into increasingly-stressful playing. In doing drills with a metronome to keep their BPM constant, these performers are likely implicitly learning to lock into certain specific BPMs as well.
My impression is that the one case where this probably isn't true, is in live jazz performance, and more specifically in live jazz improv "jam sessions." In those, the percussion (if any) isn't driving the performance, but rather is just another component of the harmony, following the (often wavering!) BPM of the lead performer.
(Is this why the classic meme of classically-trained performers not getting along with jazz artists? Because the jazz artists won't stay on beat, and this irritates some perfect-pitch-like "out of tune" feeling in the classical musician?)
> (Is this why the classic meme of classically-trained performers not getting along with jazz artists? Because the jazz artists won't stay on beat, and this irritates some perfect-pitch-like "out of tune" feeling in the classical musician?)
I think you’re getting tempo, pitch and time signature mixed up. Jazz musicians are excellent at staying on tempo. Staying on tempo is so important in jazz that when I was young, we had to earn the right to practice without a metronome. At the highest levels, jazz can be mixed with jazz because the tempo is solid enough.
Jazz though uses some time signatures that are hard to visualize. Once you’ve played them for long enough they become second nature but they’re likely the hardest part of learning to play jazz. Those time signatures are also common in classical music. Getting time signatures mixed up can sound absolutely awful and that’s a hard thing to fix on the fly unless you know the musicians extremely well (though then the odds of playing the wrong time signature are quite low). Learning to improvise is an entirely different can of poisonous snakes but in an ideal setting you wouldn’t start improvising until you can play.
Pitch can be a problem, but it’s easy to hear and correct on the fly.
As for classical and jazz musicians getting along or not, when I grew up the usual transition was classical to jazz. When jazz was first being invented, there were some racial issues between (generally Black) jazzbos and classical heads. But when I was growing up, we were all band geeks and had a lot of mutual respect for each other.
One thing I’ll note though is that music communities (much like software communities) can seem very toxic to outsiders. If you want to get good, you learn to take and give very direct feedback. It’s a problem when you have a very gifted musician playing with beginners, but amongst musicians of the same calibre, it’s a really warm, loving feeling.
I think you’re getting tempo, pitch and time signature mixed up. Jazz musicians are excellent at staying on tempo. Staying on tempo is so important in jazz that when I was young, we had to earn the right to practice without a metronome. At the highest levels, jazz can be mixed with jazz because the tempo is solid enough.
Jazz though uses some time signatures that are hard to visualize. Once you’ve played them for long enough they become second nature but they’re likely the hardest part of learning to play jazz. Those time signatures are also common in classical music. Getting time signatures mixed up can sound absolutely awful and that’s a hard thing to fix on the fly unless you know the musicians extremely well (though then the odds of playing the wrong time signature are quite low). Learning to improvise is an entirely different can of poisonous snakes but in an ideal setting you wouldn’t start improvising until you can play.
Pitch can be a problem, but it’s easy to hear and correct on the fly.
As for classical and jazz musicians getting along or not, when I grew up the usual transition was classical to jazz. When jazz was first being invented, there were some racial issues between (generally Black) jazzbos and classical heads. But when I was growing up, we were all band geeks and had a lot of mutual respect for each other.
One thing I’ll note though is that music communities (much like software communities) can seem very toxic to outsiders. If you want to get good, you learn to take and give very direct feedback. It’s a problem when you have a very gifted musician playing with beginners, but amongst musicians of the same calibre, it’s a really warm, loving feeling.
> In those, the percussion (if any) isn't driving the performance
Wrong, drums (or the bass) most usually is driving the rhythm, and jazz musicians are extremely adept at staying on tempo.
> Because the jazz artists won't stay on beat, and this irritates some perfect-pitch-like "out of tune" feeling in the classical musician?)
Try the exact opposite. https://www.youtube.com/watch?v=rEbUNDW9bDA
> you'd have to fight the DAW to not.
That's just outright false. This is a basic action in all commonly used DAWs. eg https://promixacademy.com/blog/how-to-nudge-tracks-in-logic-...
Wrong, drums (or the bass) most usually is driving the rhythm, and jazz musicians are extremely adept at staying on tempo.
> Because the jazz artists won't stay on beat, and this irritates some perfect-pitch-like "out of tune" feeling in the classical musician?)
Try the exact opposite. https://www.youtube.com/watch?v=rEbUNDW9bDA
> you'd have to fight the DAW to not.
That's just outright false. This is a basic action in all commonly used DAWs. eg https://promixacademy.com/blog/how-to-nudge-tracks-in-logic-...
There aren't really reference BPM's.
Not everything is recorded with a click track, though a lot is.
But even so, while it will usually be an integer BPM, it's not always rounded to the nearest 5. 120 might be too fast while 115 is too slow, so you pick 118.
For an app that's trying to correct your turntable speed by e.g. 3%, it couldn't even begin to guess the "correct" BPM.
Not everything is recorded with a click track, though a lot is.
But even so, while it will usually be an integer BPM, it's not always rounded to the nearest 5. 120 might be too fast while 115 is too slow, so you pick 118.
For an app that's trying to correct your turntable speed by e.g. 3%, it couldn't even begin to guess the "correct" BPM.
But would a large-enough majority of songs be recorded with a multiple-of-5 BPM, that this app could presume the first record you play has a multiple-of-5 BPM, and be right 80+% of the time?
If so, then that could still be how it was done here. It wouldn't always work for the first record, but you'd be highly likely to get a "good reading" by at least the third one you try.
If so, then that could still be how it was done here. It wouldn't always work for the first record, but you'd be highly likely to get a "good reading" by at least the third one you try.
So I found some data and the answer is -- definitely not:
https://assets-global.website-files.com/6188e55dd468b56ab674...
from:
https://blog.musiio.com/posts/which-musical-tempos-are-peopl...
There are plenty of songs ending in every integer.
https://assets-global.website-files.com/6188e55dd468b56ab674...
from:
https://blog.musiio.com/posts/which-musical-tempos-are-peopl...
There are plenty of songs ending in every integer.
All the turntables in my life as a kid had built-in calibration, in the form of four rows of repeating black/silver squares on the side of the wheel, a light flickering at the mains frequency, and a little dial to adjust the turning speed until the row of squares corresponding to your current combination of 50/60 hz DC and 33/45 RPM appeared to stop moving. It was a very clever trick.
You had access to nicer turntables as a kid! That was a distinguishing feature between the more "serious" music hobbyist and the person who just wanted to play some tunes.
I haven't messed around with a turntable in over 20 years but these days, only the supposed "serious" music hobbyist would be using a turntable and I'd think anyone making a turntable that didn't have this adjustment would be laughed out of the market. What are you going to tell me next - they're also using belt drive, a plastic needle, and a tone arm with a non-adjustable counterweight?! :)
I haven't messed around with a turntable in over 20 years but these days, only the supposed "serious" music hobbyist would be using a turntable and I'd think anyone making a turntable that didn't have this adjustment would be laughed out of the market. What are you going to tell me next - they're also using belt drive, a plastic needle, and a tone arm with a non-adjustable counterweight?! :)
My dad was a recording engineer, so he knew where to go to find the sweet spot between "this sounds great" and "this sounds insanely fabulous but requires a second mortgage".
And yeah honestly I'm surprised you can get a turntable that isn't made for the audiophile market any more, but the one shown in the video for this app sure does lack any fine speed adjustment. Just a little button labeled 33/45.
And yeah honestly I'm surprised you can get a turntable that isn't made for the audiophile market any more, but the one shown in the video for this app sure does lack any fine speed adjustment. Just a little button labeled 33/45.
> And yeah honestly I'm surprised you can get a turntable that isn't made for the audiophile market any more
It's because of the other re-emerged market for vinyl: the "not-so-enthusiastic" collectors, who just want the album "on vinyl" to say they have the album "on vinyl" or maybe "in every possible format"; or because they love the band and the vinyl is just what you happen to get when you buy the special collector's edition box-set; or because they want to display the vinyl album cover somewhere visible in their house as if it were a poster print; or because they consider "a vinyl collection" to be an aesthetic decor item, like some people consider a full bookshelf to be an aesthetic decor item.
A lot of these are people in their teens/20s who don't actually think that vinyl sounds better, so don't have much enthusiasm for actually listening to the vinyl release (as they're mostly buying new vinyl, and these tend to come with a code for a digital copy as well.) So if they bother to buy a turntable, it's the $30 one they say at Urban Outfitters. They know they're just listening to the vinyl as a novelty experience, something they're only going to be doing a few times — and so they don't want to waste too much money on it.
It's because of the other re-emerged market for vinyl: the "not-so-enthusiastic" collectors, who just want the album "on vinyl" to say they have the album "on vinyl" or maybe "in every possible format"; or because they love the band and the vinyl is just what you happen to get when you buy the special collector's edition box-set; or because they want to display the vinyl album cover somewhere visible in their house as if it were a poster print; or because they consider "a vinyl collection" to be an aesthetic decor item, like some people consider a full bookshelf to be an aesthetic decor item.
A lot of these are people in their teens/20s who don't actually think that vinyl sounds better, so don't have much enthusiasm for actually listening to the vinyl release (as they're mostly buying new vinyl, and these tend to come with a code for a digital copy as well.) So if they bother to buy a turntable, it's the $30 one they say at Urban Outfitters. They know they're just listening to the vinyl as a novelty experience, something they're only going to be doing a few times — and so they don't want to waste too much money on it.
Damn! I hadn't even considered that. You've opened my eyes to a world a never knew existed.
I would think that any turntable that allows for adjustment of the speed of the motor would have this already (based on my limited experience with turntables from decades ago). So, nice little app, but if it shows you the error of a non-adjustable turntable, it won't have a lot of practical applications.
For turntables which lack the inbuilt strobe but have the calibration pattern on the edge, you can also download a strobe app for your phone and use that to accurately measure and tune your turntable speed.
We have replaced a lot of stepper motors with a more refined version of this using stripes and a photoreceptor. Printers for instance. Surely there must be turntables doing the same thing?
And for those that don't have that, a strobe disc can be downloaded and printed.
On a quartz deck like the 1200 mk2, the strobe is also quartz right, not mains? (Otherwise the strobe would be far less accurate than the motor..)
Same here, so I was scratching my head about the need for this. For the turntables that for some reason didn't have this (one example would be one I built myself) you could get cheap strobe discs which you just put on the turntable, kind of like a tiny record.. start the turntable, and you would immediately see if it was in sync with (in this case) 50Hz.
I never knew what the heck those squares were for!
Just thought they were some funny aesthetic choice from the 70's and 80's.
Thanks for giving me the definitive answer for something that has always seemed odd to me.
Just thought they were some funny aesthetic choice from the 70's and 80's.
Thanks for giving me the definitive answer for something that has always seemed odd to me.
My Dual turntable from the 80ties is regulated by a quartz crystal. This thing calibrates itself. :-)
This is cool - not sure if it's possible, but it would great if you could determine other things, like is the needle weight correct, or is the cartridge aligned properly (maybe left / right channel would be louder / softer??).
I found the copy on the site a bit gross - I'm not sure something like this needs a critique of modern copywriting, and for me it gives that same weird sense of over familiarity ('we get you') that I think it's trying to criticise.
I found the copy on the site a bit gross - I'm not sure something like this needs a critique of modern copywriting, and for me it gives that same weird sense of over familiarity ('we get you') that I think it's trying to criticise.
I'm just here to say that I enjoyed that intro you gave to the website, and although I hate unitaskers in the kitchen, that intro helped to remind me of the magical wonder of them in the early days of "The Modern Smartphone".
Cool app and thanks for sharing! :D
Cool app and thanks for sharing! :D
I've tried this on a dozen or so records and all I get is "Please made sure your device can hear the music, and that you're using a modern song with a clearly defined beat."
(There is definitely a very well defined beat.)
(There is definitely a very well defined beat.)
That's odd, could you share an example of a record you use? Are those fairly popular/common records?
Also, do you see the little disk outline moving during the analysis? This would confirm that your phone can hear the sound coming out of your record player (just to be safe: you need to play the song out loud)
Also, do you see the little disk outline moving during the analysis? This would confirm that your phone can hear the sound coming out of your record player (just to be safe: you need to play the song out loud)
I've tried the White Album, Tiffany (I think we're alone now), and a bunch of songs on Cake Comfort Eagle.
No, the disk is not moving at all! It's turned up pretty loud.
No, the disk is not moving at all! It's turned up pretty loud.
That's super odd. So it's not even rotating? There might be an issue that occurs before the analysis starts.
If you don't mind, do you have any special setting on? Lockdown mode or something? Are you able to play the music back if you use the Voice Memo app to record a bit of it?
Sorry about all that, hopefully we can figure out what's wrong!
If you don't mind, do you have any special setting on? Lockdown mode or something? Are you able to play the music back if you use the Voice Memo app to record a bit of it?
Sorry about all that, hopefully we can figure out what's wrong!
Yep, voice memo works fine, not on lockdown (not sure what that is).
Basically it's a setting for people who are concerned about being targeted by 0days.
> Lockdown Mode is an optional, extreme protection that’s designed for the very few individuals who, because of who they are or what they do, might be personally targeted by some of the most sophisticated digital threats.
https://support.apple.com/en-us/105120
> Lockdown Mode is an optional, extreme protection that’s designed for the very few individuals who, because of who they are or what they do, might be personally targeted by some of the most sophisticated digital threats.
https://support.apple.com/en-us/105120
Very strange... Best I can offer is to delete and reinstall the app to reset the microphone permissions, or if you'd like you can send me an email via my website (okat.best) and we can try to troubleshoot it
OK, deleting and reinstalling works, and now it works.
I'm concerned that the app does not work at all in airplane mode - like, even navigating between pages ("return to home" from a failure).
It also doesn't work (even without airplane mode) for songs that Shazam fails on - so I guess we've confirmed that that's how this works!
I'm concerned that the app does not work at all in airplane mode - like, even navigating between pages ("return to home" from a failure).
It also doesn't work (even without airplane mode) for songs that Shazam fails on - so I guess we've confirmed that that's how this works!
I've used to use an app (there are many) which measures angular velocity using accelerometer and displays RPM (you place the phone on the turntable). I can't see why would anyone need something other than that.
Complete noob here, but wouldn't the phones weight (especially with how big phones are nowadays) have a significant impact on the RPM by slowing it down?
It's very possible, increased weight will increase friction in the bearing. However my iphone SE weighs almost the same as a 12-inch record (150g). BUT it is also more difficult to place symmetrically on the turntable, which also could affect friction.
So is this just a test to see if it's playing records at the right speed? Does it do anything else? Is it comparing it to a known-good recording of the song or is it measuring how many cents the song deviates from a natural key? If it's the latter, I can say that I have many many records don't play back in a natural key.
I have several records (45's) in my collection whose hole is not punched perfectly in the center and the pitch wavers up and down as the record rotates. How would this app react to that and what suggestion might it make to mitigate?
I have several records (45's) in my collection whose hole is not punched perfectly in the center and the pitch wavers up and down as the record rotates. How would this app react to that and what suggestion might it make to mitigate?
Oh, you could probably solve that concentricity error by looking at the subtle repetitive wobbles in the spectrum. Period of the wobble would be related to the radius from the center, and the amplitude of the spectral shift would be relative to the radius and the concentricity error.
I suspect modern direct drive could handle the modulation of their speed. I suspect this has been done already.
I suspect modern direct drive could handle the modulation of their speed. I suspect this has been done already.
What a perfectly simple app! Going to try this out with my Technics SL1200 mk2 tonight. Thanks for sharing.
P.S. Reading comments from a bunch of tech folks trying to wrap their heads around an app for calibrating analogue music playback device is very amusing. :-)
P.S. Reading comments from a bunch of tech folks trying to wrap their heads around an app for calibrating analogue music playback device is very amusing. :-)
I assume this is for belt driven turntables, not direct drive. I also have a pair of 1200's. Most mixers these days have BPM built in, and before that you had red micro bpm counters and headphone amps to validate BPM. Never once on my 1200's did it read something outside of the producers BPM count when pitch was locked.
My MK2 was off by about 3% when the pitch adjust was in the detent. To be fair, it had a rough life before it ended up in my hands. If you have a frequency counter they're pretty easy to calibrate the correct way though.
Did the delta show up on the strobe? Or is issue that the quartz is off and it’s feeding both the motor and the strobe? (Sorry if this is a dumb question. I don’t recall seeing speed calibration in the mk2 manual when I was setting up my secondhand decks)
I honestly can't remember if it showed up in the strobe or not, this was a few years ago. This procedure wouldn't be listed in the regular manual. It involves opening it up to adjust an internal potentiometer, and can't be reliably done without a frequency counter (I guess you could do it through trial and error, but it would take forever having to reassemble it and play a test disc after every adjustment,) so it is only in the service manual. You should be able to find a scan pretty easily though. Can't remember what frequency you need to hit, but it's low. If you don't have a proper frequency counter an Arduino will work just fine.
I'm skeptical; you have no idea whether a random song from a record player is in tune or not, without a reference copy of that song from digital media.
Is this zeroing in on traces of 60 cycle hum in the recording?
Or else, won't it adjust an out-of-tune song to be in concert pitch? (Mind you, that would be extremely useful if you're playing along with the track and don't want to adjust your instrument, or cannot do so.)
To get it to the correct speed, I would go through my record collection and find a tune with long, sustained notes. Find the same tune on Youtube and get a pitch reference for the note using a digital tuner. Then adjust the record player to match the pitch on that note, down to 1/10 of a Hz precision.
(In the first place, why would you have a record player without a built-in strobe light for adjusting the speed in 2024, when this was a common item even in lower income households in 1984.)
Is this zeroing in on traces of 60 cycle hum in the recording?
Or else, won't it adjust an out-of-tune song to be in concert pitch? (Mind you, that would be extremely useful if you're playing along with the track and don't want to adjust your instrument, or cannot do so.)
To get it to the correct speed, I would go through my record collection and find a tune with long, sustained notes. Find the same tune on Youtube and get a pitch reference for the note using a digital tuner. Then adjust the record player to match the pitch on that note, down to 1/10 of a Hz precision.
(In the first place, why would you have a record player without a built-in strobe light for adjusting the speed in 2024, when this was a common item even in lower income households in 1984.)
Unfortunately a lot of mid-range tables nowadays don't have the strobe (mine included), most likely for aesthetic reasons... Even just looking at online shopping right now I only see a handful that do have it.
As for being skeptical, good! That means I'm doing something great according to Clarke's third law.
You can see me testing out the app on multiple records here: https://twitter.com/OKatBest/status/1795453042994680148
The results aren't 100% perfect, and they definitely won't be as good as matching specific frequencies, but it'll get you very close to the ideal RPM.
As for being skeptical, good! That means I'm doing something great according to Clarke's third law.
You can see me testing out the app on multiple records here: https://twitter.com/OKatBest/status/1795453042994680148
The results aren't 100% perfect, and they definitely won't be as good as matching specific frequencies, but it'll get you very close to the ideal RPM.
Building a "strobe" is just a matter of putting an LED, some diodes, a resistor, and (optionally) a transformer together.
The idea is that the LED reaches peak brightness (and darkness) at twice the line frequency, just as ye olde fluorescent tubes did. (Or: Skip the extra diodes and have it work at 1x line frequency. I'm not your boss.)
After that, just print a strobe disc and use it.
The idea is that the LED reaches peak brightness (and darkness) at twice the line frequency, just as ye olde fluorescent tubes did. (Or: Skip the extra diodes and have it work at 1x line frequency. I'm not your boss.)
After that, just print a strobe disc and use it.
Or even simpler, use a Neon bulb. or even a Fluro light.
Indeed.
But little neons are getting scarce (they aren't dear -- they're just much, much less common than they used to be). And working fluorescents (with magnetic ballasts that actually run at line frequency) are pretty much that way are too.
LEDs and resistors, though? Bright, cheaper than chips, and ready for all kinds of modern digital shenanigans.
But little neons are getting scarce (they aren't dear -- they're just much, much less common than they used to be). And working fluorescents (with magnetic ballasts that actually run at line frequency) are pretty much that way are too.
LEDs and resistors, though? Bright, cheaper than chips, and ready for all kinds of modern digital shenanigans.
60 cycle hum probably would not work, europe uses 50hz
That's a big enough discrepancy that the program could have heuristics to figure it out, particularly if the record player is in the right ballpark.
Also west Japan is 50, east 60.
The main problem is: (1) there isn't a lot of hum on professionally produced records; (2) but there may be hum from the equpiment itself.
Also west Japan is 50, east 60.
The main problem is: (1) there isn't a lot of hum on professionally produced records; (2) but there may be hum from the equpiment itself.
Cool idea but for a surprising reason I don't need it.
Towards the end of the classic era of Japanese hi-fi, even mid-fi turntables out of Japan made this app superfluous. There were quite a few "quartz locked" models which offer great speed fidelity without having to muddle around with anything.
As an example, the Technics SL1400 Mk 2 is a quartz locked, direct drive table that has a little window so you can see the speed on the turntable markings AND has digital adjustment of the speed, not that you ever need to move it off 0 because it's already spot on.
I also have a cheaper JVC table (QL-A2) which doesn't have the crazy adjustability of the Technics, but is still spot-on all the time.
I can see this app being useful for cheap, modern belt drive garbage they are shovelling out now.
Towards the end of the classic era of Japanese hi-fi, even mid-fi turntables out of Japan made this app superfluous. There were quite a few "quartz locked" models which offer great speed fidelity without having to muddle around with anything.
As an example, the Technics SL1400 Mk 2 is a quartz locked, direct drive table that has a little window so you can see the speed on the turntable markings AND has digital adjustment of the speed, not that you ever need to move it off 0 because it's already spot on.
I also have a cheaper JVC table (QL-A2) which doesn't have the crazy adjustability of the Technics, but is still spot-on all the time.
I can see this app being useful for cheap, modern belt drive garbage they are shovelling out now.
You talk like belt drive turntables are something new. Most people had belt turntables.
Direct drive and stroboscopic quartz are only a must for djs.
Direct drive and stroboscopic quartz are only a must for djs.
This is cool although it very confidently asserted that a 45 rpm 12” single was a perfect! 33 1/3 rpm.
Which suggests this is using song recognition and not discovering some underlying truth of the spinning platter.
Which suggests this is using song recognition and not discovering some underlying truth of the spinning platter.
Very good data point for the folks wondering if it's detecting the period of wow or scratches -- this likely proves that it's not (unless it can adapt to all common RPMs, but then it would show that).
frequencySkew from ShazamKit, as mentioned elsewhere here, is my guess.
frequencySkew from ShazamKit, as mentioned elsewhere here, is my guess.
Great idea! Thank you!
However, I don't think I'll ever use it.
My turntable doesn't have an adjustment for speed outside of 45s. So, if I find out that my table is too fast or slow, that's just going to bug me forever. So, I'd rather not know, seeing as I'm enjoying the music just fine as is.
If you can, try selling this out to an adjustable turntable manufacturer in stock options, so that when all the people find out their turntable doesn't spin quite right and then go spend to buy a new one they can adjust, you'll make even more money.
However, I don't think I'll ever use it.
My turntable doesn't have an adjustment for speed outside of 45s. So, if I find out that my table is too fast or slow, that's just going to bug me forever. So, I'd rather not know, seeing as I'm enjoying the music just fine as is.
If you can, try selling this out to an adjustable turntable manufacturer in stock options, so that when all the people find out their turntable doesn't spin quite right and then go spend to buy a new one they can adjust, you'll make even more money.
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This is a neat idea. I don't know why it needs to be an app on a phone though. I guess you "know" a phone has a microphone and the setup is minimal and you have a api for everything? It being a phone app leads me to believe the 'no data collected' bit is temporary as all phone apps eventually gobble data to sell.
I have an Android so I can't try this out, as its in 'private beta' on Android currently.
Would love to see this as a open source project that I can install on Windows or Linux though.
I have an Android so I can't try this out, as its in 'private beta' on Android currently.
Would love to see this as a open source project that I can install on Windows or Linux though.
Probably a smart idea to be suspicious of new apps, though I will say I am someone who care deeply about privacy. You can take a look at my previous project Boop ( https://boop.okat.best/ ), which is open source and has been on the App Store for 6 years, yet I still don't have any analytics or data collection in it. I have no clue how many people use it beyond download figures I get from Apple.
I have considered making this app open source, and it may still happen in the future, but I do want to release the Android version first. I'm worried that somebody will see my code, repackage it with a new name, beat me with better SEO (which would be easy considering how dumb the copy is on my website) and sell it for profit before I have a chance to reach a wider audience. This is something that did happen with Boop, not a hypothetical.
The reality is that this app cannot collect anything valuable either way. It's a simple serving app that only uses your microphone for a couple of seconds at a time, and I assume most people will delete it once it serves its purpose. If I wanted to monetize it, the best way would be to add a "Pro" version with a subscription or to add ads, but I have no interest in doing either. This is a fun side project/portfolio piece, and I'd rather collect internet love distributing a ton of free copies, rather than sell a small fraction of that number of paid copies for $0.99 and have to deal with things like marketing, taxes, and customer support.
I have considered making this app open source, and it may still happen in the future, but I do want to release the Android version first. I'm worried that somebody will see my code, repackage it with a new name, beat me with better SEO (which would be easy considering how dumb the copy is on my website) and sell it for profit before I have a chance to reach a wider audience. This is something that did happen with Boop, not a hypothetical.
The reality is that this app cannot collect anything valuable either way. It's a simple serving app that only uses your microphone for a couple of seconds at a time, and I assume most people will delete it once it serves its purpose. If I wanted to monetize it, the best way would be to add a "Pro" version with a subscription or to add ads, but I have no interest in doing either. This is a fun side project/portfolio piece, and I'd rather collect internet love distributing a ton of free copies, rather than sell a small fraction of that number of paid copies for $0.99 and have to deal with things like marketing, taxes, and customer support.
I understand your hesitation in opening the code. Still, the idea seems really great, low complexity (quick local processing, no database of songs needed) and robust (any reasonable vinyl could work).
I suggest considering writing about it. Maybe a whitepaper? A publication? A patent application? May be colab with audio researchers? Or get sponsored from an audiophile record player manufacturer?
I suggest considering writing about it. Maybe a whitepaper? A publication? A patent application? May be colab with audio researchers? Or get sponsored from an audiophile record player manufacturer?
> I'm worried that somebody will see my code
But you're not worried that HN folks might run the app through a decompiler and find something approximately as revealing as your source code would be? The results might not be ideal depending on how much obfuscation you use, but I think it would be enough for someone to get the gist of how to replicate.
But you're not worried that HN folks might run the app through a decompiler and find something approximately as revealing as your source code would be? The results might not be ideal depending on how much obfuscation you use, but I think it would be enough for someone to get the gist of how to replicate.
I have no issue with people decompiling my code for fun or curiosity. I often put easter eggs in my code or built files for this specific purpose. I never use obfuscation unless there is a security component.
The important part is the rest of that sentence, I have an issue with people who steal the code (or concepts) and charge money for it. If I do end up open-sourcing the code later, people will see the code and I have no issue with that.
The important part is the rest of that sentence, I have an issue with people who steal the code (or concepts) and charge money for it. If I do end up open-sourcing the code later, people will see the code and I have no issue with that.
Funny, I have the exact opposite intuition as you. It being a totally-sandboxed phone app means I can trust it not to collect any data without my knowledge, without me having to spend hours looking through the source code for some trick I might miss.
Random though from non-vinyl-aficionado here: Is there an easy way to temporarily leave a mark (and thus a sound) on the surface of the record, so that you can easily measure the time of each revolution without damaging the record or the needle?
At first I thought of a small square of scotch-tape, although I expect that might "catch" and damage the stylus. Perhaps blu-tack? A big water droplet?
At first I thought of a small square of scotch-tape, although I expect that might "catch" and damage the stylus. Perhaps blu-tack? A big water droplet?
There are weights with strobe patterns that you can put on.
I know you can buy strobe mats/discs and view them under a precisely flickering light (sometimes fluorescent lights with the right power-grid frequency) but I guess I was trying to think of something one could use in a pinch that wouldn't involve a separate purchase of things beyond household items. (Excluding the smartphone, which I assumed would be ubiquitous.)
Nice work! This looks really good.
I'm not in the intended audience as I don't have a turntable, but if I had one I feel like I would be much more likely to use this if it was a web app. If I didn't know about this app beforehand, I'm pretty sure I'd be looking on Google rather than the App Store.
That being said, you made this app for yourself and it looks great. Congrats on shipping!
I'm not in the intended audience as I don't have a turntable, but if I had one I feel like I would be much more likely to use this if it was a web app. If I didn't know about this app beforehand, I'm pretty sure I'd be looking on Google rather than the App Store.
That being said, you made this app for yourself and it looks great. Congrats on shipping!
This is awesome. As a fellow (dare I say luddite), technologist that hates the centralized greed digital internet tech has enabled with media, vinyl records are an outstanding hold out for individuals to still archive (and OWN!) their music. Thank you for investing in the movement with your valuable hours in making this app.
I don't like how it doesn't explain how it works.
Does it rely on the fact that music has a concept of notes with well-defined frequencies and that there is no such thing as 216 Hz (must be 207.6 or 220 Hz) when the music is played on a properly tuned instrument? Or does it use other heuristics?
I tried it out and the instructions have tips on what record to pick, they say to pick a well known version of a song (like not a live version etc), and preferably song with a beat, but it says it doesn’t use any 3rd party APIs or libraries, only Apple APIs. So my guess at to what it’s doing is using a ShazamKit recognition behind the scenes and looking at the frequencySkew value of the matched result. It also gives you one answer after listening, instead of a continuous gauge, which seems to corroborate song recognition. It probably won’t work with an obscure record that is not Shazamable. And so I don’t think it can measure wow & flutter as a result.
Still pretty cool for those that need to calibrate a turntable, or verify 33 vs 45 PRM for a record.
Still pretty cool for those that need to calibrate a turntable, or verify 33 vs 45 PRM for a record.
I love that everyone is guessing all these methods of detecting pitches or using the camera to count rotations, and it turns out that they're most likely literally just using a built-in API and displaying a return value [0].
0: https://developer.apple.com/documentation/shazamkit/shmatche...
0: https://developer.apple.com/documentation/shazamkit/shmatche...
I guess a phone's camera can be used to count the RPM, e.g. by filming the label and counting how many milliseconds it needs to do a full rotation (1818ms for a 33 RPM record)
I tried to build a prototype of something like this with opencv once, didn't get it to work reliably though. I have a feeling there should be a relatively simple signal processing version of this, basically a spatiotemporal Fourier transform, that should solve it.
I would go with something like sift features (or a non patented variant thereof if you plan commercial usage).
You analyze a first picture and extract the center part. You run a feature detector on each image and the can cheaply match (scale and rotation invariant) against each other - this gives rotation and scaling.
Yea that's precisely what I ended up doing, but the frame extraction was quite finicky.
How can it use ShazamKit if it processes everything on-device?
I'm really really curious how this is done now...
I'm really really curious how this is done now...
They don't claim everything is done on-device, just that the audio stream processing is.
> Grooved does not collect any data, whatsoever. The audio stream is processed locally on your device and never recorded.
Which is consistent with how ShazamKit works [0]:
> Audio is not shared with Apple and audio signatures cannot be inverted, ensuring content remains secure and private.
0: https://developer.apple.com/shazamkit/
> Grooved does not collect any data, whatsoever. The audio stream is processed locally on your device and never recorded.
Which is consistent with how ShazamKit works [0]:
> Audio is not shared with Apple and audio signatures cannot be inverted, ensuring content remains secure and private.
0: https://developer.apple.com/shazamkit/
I'm not a turntable owner myself, so the app doesn't offer a lot of value to me. In thinking about it though, this app reminds me of the early days of mobile apps, where folks made neat, useful little tools to make life better. It wasn't about making a platform, or figuring out how to make a six figure sum, just a neat little ecosystem of fun and useful tools made by folks that had a problem to solve, and thought someone else might find it useful.
I see that it's free, but I feel like this could have easily been a $1 app.
Grats on making a really neat little focused tool!
I see that it's free, but I feel like this could have easily been a $1 app.
Grats on making a really neat little focused tool!
Looks amazing and useful for me! The links don’t take me to the app store on my iphone and the app name is not in the heading I need to scroll past the copy to find what to search for. Minor annoyance but for some reason annoyed me a lot. That annoyance led me to hate the copy as I was searching for the app name and tried to skim the text. This is probably the first time I write any feedback to internet. I am usually not one that does that kind of thing haha. Ok, now I will search and install the app. I bet it’s great.
Hey that's very odd, would you mind telling me which country/region you are located in?
I actually released the app yesterday but didn't post about it til today because it wasn't being indexed properly on the App Store yet, it's possible that it's still not live everywhere. I have an image link to the listing in the first section of the web page and if on iPhone it should show you the classic "this website has an app" banner at the top.
If you're searching for it, "Grooved" has many results but if you accept the suggestion of "Grooved: turntable calibration" it'll come up.
This is a direct link to the store page: https://apps.apple.com/app/grooved-turntable-calibration/id6... Please let me know if it still doesn't work and I can take a look... Thanks!
I actually released the app yesterday but didn't post about it til today because it wasn't being indexed properly on the App Store yet, it's possible that it's still not live everywhere. I have an image link to the listing in the first section of the web page and if on iPhone it should show you the classic "this website has an app" banner at the top.
If you're searching for it, "Grooved" has many results but if you accept the suggestion of "Grooved: turntable calibration" it'll come up.
This is a direct link to the store page: https://apps.apple.com/app/grooved-turntable-calibration/id6... Please let me know if it still doesn't work and I can take a look... Thanks!
I figured that the site breaks with apple lockdown mode on. I think that appstore links usually work still, but might be that that’s one of the lockdown mode protections. The spinning animation also was not there so I didn’t see the app logo there.
That's very good to know, I didn't even think to test it with lockdown mode! I'll see if I can add a fallback page if the content is missing. Thanks!
This just tells you the speed, not the variation in speed over time?
That's correct. The analysis takes a few seconds so even if I take more samples, it all gets averaged over time and won't be able to do instant read. If you're interested in measuring wow and flutter I think you'll need to look at more traditional calibration methods unfortunately.
You can get apps where you place your phone on the turn table and it directly measures the turntable speed using either gyroscope or compass
https://play.google.com/store/apps/details?id=com.vinylrpm&h...
This is how this project started! I thought I was super smart figuring out I could do that, then I realized there are many apps that already do the same thing. Eventually I decided to see if I could find a novel, more user-friendly approach that doesn't require you to put a thousand-dollars phone on a fast moving spinning thingie, and that's how Grooved came to be.
Here I was thinking it'd be smart to have the app use the camera to figure out how fast the middle label is spinning around but this seems way simpler now that you mention it.
Great! In the past I've used the app that measures the turntable speed through its accelerometer...it's somewhat uncomfortable and weird to set the mobile on the turntable, start and stop once and again. Would love to see a comparison of measurements taken with your app and the one using the accelerometer...calibration is a huge thing in engineering.
I'm gonna be honest, using the accelerometer will definitely be more accurate because you can take more samples over a longer period of time. That's how this project started, but I also felt uncomfortable putting my brand new phone on a fragile player and even more so asking other people to do the same.
Grooved is still very accurate, especially if you run multiple measurements to confirm on multiple songs/records. The threshold for "perfection" in the app is 0.01%, which to me anything beyond that is a rounding error and I could not tell the difference in my tests. This is equal to a drift of about a third of a second over an hour of listening.
Grooved is still very accurate, especially if you run multiple measurements to confirm on multiple songs/records. The threshold for "perfection" in the app is 0.01%, which to me anything beyond that is a rounding error and I could not tell the difference in my tests. This is equal to a drift of about a third of a second over an hour of listening.
I wonder how this would behave with the two different speed versions of the Beatles song revolution
So this is super cool but i am questioning its reliability after playing a song from Spotify on my Sonos and then letting the app listen: the result was 0.1% too slow? I guess that’s a very small difference, what’s the degree of error to expect here?
So this is an excellent question, because no joke I have noticed the same thing testing with Spotify. Apple Music does not have that issue.
Makes me wonder: do different streaming services get different masters? Or, is Spotify having playback issues? To the app, they both should sound the same. I intend to do some research with that when the fog clears out a bit and the Android version is out.
Makes me wonder: do different streaming services get different masters? Or, is Spotify having playback issues? To the app, they both should sound the same. I intend to do some research with that when the fog clears out a bit and the Android version is out.
I just played Bad Religion - Incomplete on YT Music through Sonos, app said "That's pretty much perfect". Played the same track on vinyl, app reported 3.5% too fast. Dev answered elsewhere on the post that .01% is required for the perfect message.
I'm not an expert on vinyl. The only record players I've interacted with have only had two speeds. Do most of them do variable spin rates?
How frequently do the rates get out of sync? What causes it? Do they vary on an album by album basis?
How frequently do the rates get out of sync? What causes it? Do they vary on an album by album basis?
So you have multiple speed settings (33.3RPM, 45RPM etc.), but most if not all players also have a little adjustment knob to tweak those settings more precisely.
Good players will have it on the front, and will have a strobe to help you adjust that (the little dots you see on the outside of the platter on fancy players). However, cheaper players may not have an easy way to adjust, and some (like mine) hide the knob under so it's a pain to adjust.
Cheaper players are more likely to come misconfigured from the factory. I asked a lot of friends (who are amateurs, not audiophiles) to test this app out and every single one had a turntable that required adjustment. Mine's running at 34.6 RPM which is just 3% off, but when listening to my favorite albums I can definitely tell that it's too fast and too high pitched.
The speed will also sometimes drift slowly over time, which is why it took me a while to notice my table was off.
If you have a turntable, you can try listening to the same song from a record and from a digital release, and see if you can hear a difference. If you do, I know just the app for you!
Good players will have it on the front, and will have a strobe to help you adjust that (the little dots you see on the outside of the platter on fancy players). However, cheaper players may not have an easy way to adjust, and some (like mine) hide the knob under so it's a pain to adjust.
Cheaper players are more likely to come misconfigured from the factory. I asked a lot of friends (who are amateurs, not audiophiles) to test this app out and every single one had a turntable that required adjustment. Mine's running at 34.6 RPM which is just 3% off, but when listening to my favorite albums I can definitely tell that it's too fast and too high pitched.
The speed will also sometimes drift slowly over time, which is why it took me a while to notice my table was off.
If you have a turntable, you can try listening to the same song from a record and from a digital release, and see if you can hear a difference. If you do, I know just the app for you!
Fancy record players have a trim setting where you can fine adjust the speed up or down a semitone. But all of them have a built in stroboscope/calibrator to help get the speed right. I think the drag of the needle impacts the speed, hence the desire to tune it per record.
Audioplebs need not apply.
Audioplebs need not apply.
> I'm not an expert on vinyl. The only record players I've interacted with have only had two speeds. Do most of them do variable spin rates?
Lots of turntables have variable speed, DJs can tell you more about it :)
> How frequently do the rates get out of sync? What causes it? Do they vary on an album by album basis?
When you're DJing, one of the main things you'd deal with, is making things be in sync, one way or another. I'm not sure how much value you'd get from an app like this that seems to be more "fire and forget" and not for on-the-fly matching.
I'm guessing this app is for people who do their own maintenance, repairs and such of turntables, so they can easily verify their work.
Lots of turntables have variable speed, DJs can tell you more about it :)
> How frequently do the rates get out of sync? What causes it? Do they vary on an album by album basis?
When you're DJing, one of the main things you'd deal with, is making things be in sync, one way or another. I'm not sure how much value you'd get from an app like this that seems to be more "fire and forget" and not for on-the-fly matching.
I'm guessing this app is for people who do their own maintenance, repairs and such of turntables, so they can easily verify their work.
I don’t think this would be aimed at DJ turntables. It doesn’t matter if those things drift because you’re never playing anything locked in at a specific RPM.
Plus DJ turntables tend to be direct drive, which should be pretty consistent. Where as consumer record players tend to be more belt drives. And I’m assuming those belts can stretch with time?
Plus DJ turntables tend to be direct drive, which should be pretty consistent. Where as consumer record players tend to be more belt drives. And I’m assuming those belts can stretch with time?
> I don’t think this would be aimed at DJ turntables
I agree :)
> Plus DJ turntables tend to be direct drive, which should be pretty consistent
Indeed, but once you start doing repairs and/or modifications, things can get fuzzy. Maybe the app would help those people?
I agree :)
> Plus DJ turntables tend to be direct drive, which should be pretty consistent
Indeed, but once you start doing repairs and/or modifications, things can get fuzzy. Maybe the app would help those people?
People who are serious about turntable repair have calibration records with sine waves for that purpose.
So really short description, you have 33, 45, and 78 rpm.
Most record players are belt drive. Anything that is belt drive usually has some slip / variation (if more familiar to you, imagine the belt drive on a lawn tractor). Many have a finer adjustment to tune the spin rate. +- off of the selected rate. (Perhaps you selected 33 rpm but it’s really spinning at 32)
I’m sure someone who knows much more then I do, could give a much better explanation along with other types of tuning. (Arm weights, needles, etc etc)
Most record players are belt drive. Anything that is belt drive usually has some slip / variation (if more familiar to you, imagine the belt drive on a lawn tractor). Many have a finer adjustment to tune the spin rate. +- off of the selected rate. (Perhaps you selected 33 rpm but it’s really spinning at 32)
I’m sure someone who knows much more then I do, could give a much better explanation along with other types of tuning. (Arm weights, needles, etc etc)
Is the problem really the slip in the belt drive? I thought its just the motor driving it at a slightly wrong speed.
That may be the case, my experience is with a limited number of record players.
I only commonly use a dual 1219, dual 1229, (both purchased for under $30), and a victor victrola from 1908 so my knowledge is severely limited despite having played with others it’s focused on those units.
I only commonly use a dual 1219, dual 1229, (both purchased for under $30), and a victor victrola from 1908 so my knowledge is severely limited despite having played with others it’s focused on those units.
Models targeted at DJs will have variable speed adjustment on the front panel to allow beat-matching. Some turntables for home listening will have 2 or 3 speeds with a fine adjustment for calibration.
Rates will be off due to manufacturing tolerance or mechanical wear (i.e. a loose belt slipping on a motor).
Most people don't worry about it.
It doesn't really vary album-to-album, unless you have some ridiculously heavy records that slow the motor.
Rates will be off due to manufacturing tolerance or mechanical wear (i.e. a loose belt slipping on a motor).
Most people don't worry about it.
It doesn't really vary album-to-album, unless you have some ridiculously heavy records that slow the motor.
Even a cheaper record player will often have some kind of adjustment on the motor itself. There is sometimes a small screw on the motor that can do some fine adjustments of the speed.
Belts age. Friction within the motor and the table's bearing will change over time. It is not necessarily a frequent thing that needs to be done, but usually the speed will change slightly over the life of the table.
Belts age. Friction within the motor and the table's bearing will change over time. It is not necessarily a frequent thing that needs to be done, but usually the speed will change slightly over the life of the table.
Yes, it turns out that it is rare for mass-produced mechanical devices like record players to spin at exactly the rate they are supposed to (eg 33.3 or 45). Or they can drift put of calibration over time. Often they will be a few % off or worse for really cheap players. Usually there is a way to adjust calibration by turning a small screw someplace on the machine.
DJ turn tables have a pitch fader and lights for calibration: https://www.youtube.com/watch?v=KbdK94vl_Bs.
I used to DJ with vinyl at clubs and I don't think I ever knew a DJ that looked at those lights even once.
A DJ has no use for knowing if the turntable is calibrated correctly in an absolute sense. Only whether this song is calibrated with that song. And for that, good old fashion human ears will suffice.
I wonder if this would work playing The Shaggs' Philosophy of the World record? It's notorious for having untuned guitars and the drummer doesn't seem to be following any kind of pattern.
You can get test records which have a constant tone recorded. That's the right tool for this. Not only can you measure speed, you can see small speed variations - wow, flutter, etc.
I have zero use for this app (I own no turntable), but I absolutely dig the website. Well done on what you wrote, how you wrote it, and how good it all looks!
Neat idea.
For some reason I thought this might be for calibrating cartridge alignment. If someone can come up with an easier way to correct that it would be amazing.
For some reason I thought this might be for calibrating cartridge alignment. If someone can come up with an easier way to correct that it would be amazing.
This is fantastic. In the span of 5 minutes I had my old record player calibrated. Really great work.
Wow really cool! I am going to be setting up my SL-1200 soon and I can't wait to test it out with this app.
You'll have the calibration strobe markings built in which are at least as accurate.
Thank you for your work! I‘ll download it and calibrate my WEGA P3440 turntable as soon as I‘m back home.
Very nifty; thanks for building this. Great excuse to put a record on my player.
Mine was 0.2% slow apparently…
this is very cool! Just tried this on my TT (Pro-Ject Carbon Debut EVO) and got a perfect 33 1/3 and had to brag
thanks for making this, and in general I love digital experiences that match with analog media, please keep making more and lmk if you want any free ideas
thanks for making this, and in general I love digital experiences that match with analog media, please keep making more and lmk if you want any free ideas
Neat POC, are you doing a song fingerprint then comparing speed/stretch?
It would be exciting to try your app, cause I have 2 turntables to calibrate, but I don't use google play store. Could you make it available on f-droid?
thank you Ivan looking forward to an android version!
This is really cool.
Made with Flutter?
You are genius.
sounds very niche and very useful.
+1000 coo pints from me that you don't even try to monetize via BS.
I hope that you have an option for happy customers to buy you a beer or make a donation!
+1000 coo pints from me that you don't even try to monetize via BS.
I hope that you have an option for happy customers to buy you a beer or make a donation!
Very cool. Great aesthetic and copy. No notes.
Strongly recommend updating your website to lead with some variation of "This is an offline iPhone app to help you calibrate your turntable's speed, all you need to do is play your records and the app will show you the current RPM" — wayyyyyyy too many words and other nonsense before I could figure out this is what it did.
Embed the demo video (the tweet you linked) too!
Looks great and if I still used records I would try it out! Congratulations on the launch.
EDIT: keep the rest of the writing if you'd like, I have no objection to it and I thought it was funny. But lead with what the app is and what it does!
Embed the demo video (the tweet you linked) too!
Looks great and if I still used records I would try it out! Congratulations on the launch.
EDIT: keep the rest of the writing if you'd like, I have no objection to it and I thought it was funny. But lead with what the app is and what it does!
That is fair criticism, I expected for the website itself to be polarizing. At the end of the day because this is a tiny free app I made for fun, I am willing to throw some people off of the sake of the joke, and judging by a lot of the comments I have succeeded!
Overall, my assumption is that by the time you make it to the website, you'll already know what the app does, and most people will link to the App Store directly (which is why the store listing is much clearer on what the app is/does). if not, my second assumption is that people will scroll right past that giant block of text and go to the last line which does explain what the app is in one sentence, because there isn't much more to say about it in my opinion.
If I made money off of the app I'd have a widely different approach, but in this case all I get paid with is strangers' attention and it is _very_ funny to me to spend that attention on a useless 2AM irrelevant tirade.
Overall, my assumption is that by the time you make it to the website, you'll already know what the app does, and most people will link to the App Store directly (which is why the store listing is much clearer on what the app is/does). if not, my second assumption is that people will scroll right past that giant block of text and go to the last line which does explain what the app is in one sentence, because there isn't much more to say about it in my opinion.
If I made money off of the app I'd have a widely different approach, but in this case all I get paid with is strangers' attention and it is _very_ funny to me to spend that attention on a useless 2AM irrelevant tirade.
Fair enough, congratulations on your launch and I hope you see continued success!
Don’t throw away the “this is off the record, player” line. That’s gold.
Maybe they already changed it, but there's a chapter "As easy as 1-2-3."
I'd personally move that way up. I had to scroll across all sorts of fluff and effects. I was sold by this (edit: this chapter, not the fluff)
Maybe I'd personally even research how to make the entire website just that. Where maybe step 0 is "install the app" :D
The (promised) simplicity of the app doesn't show in the communication of the website at least.
I'd personally move that way up. I had to scroll across all sorts of fluff and effects. I was sold by this (edit: this chapter, not the fluff)
Maybe I'd personally even research how to make the entire website just that. Where maybe step 0 is "install the app" :D
The (promised) simplicity of the app doesn't show in the communication of the website at least.
I thought the copy was fun and don't mind a good soapbox every once in a while, but yeah, wouldn't hurt to slip in a few words about what exactly the product does earlier on.
I'll definitely be trying this out on my decks before my next set :)
I'll definitely be trying this out on my decks before my next set :)
Updated my comment for clarification, agreed the extra copy is fun.
Also hi joe :^)
Also hi joe :^)
Yeah, but he gets great time-on-site engagement numbers by doing that. Somebody give this guy a job in Silicon Valley!
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> Let's be real, if this charade of a website was an actual startup, we'd probably wear t-shirts that say...
It's intentional. The app is free. There is a statement about this whole corp mission mindset.
This is the way it is. If people don't like it or push it away from the product, they are not the target audience.
I think this is brilliant. I understood immediately what the app does and kudos for the courage in setting the website the way it is. Was also impressed with the aesthetic of the site.
If only I had a turntable...
It's intentional. The app is free. There is a statement about this whole corp mission mindset.
This is the way it is. If people don't like it or push it away from the product, they are not the target audience.
I think this is brilliant. I understood immediately what the app does and kudos for the courage in setting the website the way it is. Was also impressed with the aesthetic of the site.
If only I had a turntable...
This is a Show HN, so I replied with my feedback. The author explicitly invited this, too, by writing:
> Would love to hear what you think about it!
> Would love to hear what you think about it!
An this is hn, where you post comments and people reply. Doesn't change the fact that I think the original comment misses the purpose of the website. Doesn't matter the downvotes I'm taking, I stand by my comment and I think there are better ways to critique the work other than to bash on an obviously conscious aesthetic choice.
So here's another method that doesn't rely on the song being detected or even a song at all:
The gyroscope on your phone is accurate enough to measure RPM to about the first decimal place at 33 1/3 - 45 rpm's just by placing your phone on the turntable flat and letting it spin.
The gyroscope on your phone is accurate enough to measure RPM to about the first decimal place at 33 1/3 - 45 rpm's just by placing your phone on the turntable flat and letting it spin.
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Great copywriting. It's very rare that I read an entire paragraph without skipping a word.
I actually disagree. There's a lot of extraneous stuff about app stores that's probably appealing to app developers but are developers the audience or audiophiles?
Agreed—and it does feel like the Apple-inspired copywriting style the author is complaining about is feeling extremely (wait for it) played. Absolutely every site is like:
"Lawn Order.
The X900's diamond-tipped rotary blades cut your grass to within 50 microns of your desired length. Overkill? Absolutely. Because it's not just your lawn—it's our passion."
"Lawn Order.
The X900's diamond-tipped rotary blades cut your grass to within 50 microns of your desired length. Overkill? Absolutely. Because it's not just your lawn—it's our passion."
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I made a little app that lets you to calibrate your turntable by putting on any record and tapping a button. It's called Grooved and it uses your phone's microphone to see how fast your platter is going, almost like magic.
You can see what it looks like in action here: https://twitter.com/OKatBest/status/1795453042994680148
The app itself is free without ads, subscriptions, or trackers. It's a tool I built for myself, and I just thought someone else might want to use it too. I have never seen this technology being used before, all other apps require you to either print something and use the camera, or to place your phone on the spinning platter and use the accelerometer.
You can grab it on the App Store, and I am working on an Android version I hope to release at some point in June.
Would love to hear what you think about it!
Ivan_