I bought a used fretless yamaha p bass a couple years ago. The guy who owned it before me installed alembic split p pickup replacements in it. Recently, the pickup height keeps raising by itself. One thing I hate about them is that there are no springs under the pickups on the height screws. the pickups are just loose sitting on foam squares. I like to play hard and i also like playing over the pickups. every time I dig my fingers in, the pickups recess deeply into the body of my bass. Would it screw up my pickups if I put springs under the pickups like normal pickups? Are alembic pickups normally set up the way I previously described? if so, whats the point? Should I just buy new pickups? that would be unfortunate because I really dig their tone. Would lock tight (the kind that still allows a set screw to move) fix my height raising problem?