I am barely starting to some slapping practice. I often get huge spikes when slapping (not popping) especially on empty strings. But I think the action on my bass is pretty high and the neck relief maybe a bit too much (I intend to make another post at some point to ask for help on adjusting those) and it doesn't seem to me that the strings are visibly hitting the pickups when slapping, although I may be wrong. The bass is an active Ibanez with humbuckers that have exposed poles. So I am...

Volume spikes on slapping