"Blade" type guitar pickups don't pick up horizontal vibration (2015)(alexkenis.wordpress.com)
alexkenis.wordpress.com
"Blade" type guitar pickups don't pick up horizontal vibration (2015)
https://alexkenis.wordpress.com/2015/10/22/guitar-pickup-theory-1-blade-vs-pole-pieces/
This has implications for timbre, because the horizontal component from pickups that have individual pole pieces is a distortion. The fundamental (first harmonic) translates to a double frequency signal, due to the string approaching the pole piece twice per cycle.