In a recorded phone conversation with Larry of Aero Pickups, he discussed many things, and one of them was single-pole-piece-per-string vs. two-pole-pieces-per-string.
I always say when you have two pole pieces per string, the note is picked up twice every time the string vibrates over the magnets.
There have been times when I’ve sent single-pole-piece-per-string pickups to professional players, where they will reply back to me and say, “What happened to my bass tone?” Some can hear the difference between single-pole-per-string and two-poles-per-string.
There is a difference and those with very good ears will hear the change. Not necessarily in a bad way, but the sound changes the way the player feels about their instrument.
