odd harmonic ringing in bass after changing pickup heights

[shoelessgrooves]

I recently lowered the pickups on my Squire fretless jazz and I started hearing this high pitch mixed in with the pitches I play. I'm not positive its a harmonic but that's the only thing I can figure at the moment. This sound is especially obvious when I play a G anywhere except the open G string. I know this is sort of a vague description but if anyone has had this problem then it should be pretty obvious what i'm talking about. My guess is that one of the pickups is causing a node on the strings which is making the harmonic, but that just a guess. Also I hear this same sound if I tap on the bridge pickup with my finger so maybe that defeats my previous idea but i'm not sure. Let me know if you have any other questions.

Thanks

[curbowman]

Check out the pickup mounts. If you have springs holding the pickups, they can vibrate at a fixed frequency. The way to test this is to mute the strings and tap the body of the bass. If the springs are vibrating, the sound will be heard clearly. This happens a lot on strat-like guitars, especially with the big tremolo springs of the back.

If the springs are causing the sound, find a way to avoid them to vibrate. I use a small piece of foam around the spring to act as a mute pad.

[SGD Lutherie]

The pickup might be too close to the string, which causes the magnet to make the string vibrate out of tune. You get a funny warbling tone.

Try lowering the pickup slightly and see if it goes away.

This is common with Fender style pickups, and is commonly known as "Stratitus", though it does happen on bass too.

[shoelessgrooves]

well i'm pretty sure that the only thing the pickups are mounted on is foam pads but thats a good thing to check, i'm pretty sure though that the pickups aren't too high cuz this problem started when I lowered them, but thanks for the responses