whats up guys, my friends dad has a BMW in which he wiring his fader adjustment to be his bas **** control from his aftermarket amp. a direct through stock headunit changing fader is controller bass. i was wondering if anyone has heard of something like this and if this is do-able. suchas when i adjust the bass from my stock headunit it will actually control the bass going to my subs, VIA bass control ****.

i hooked up 2 12" Kicker CVX subs powered by 2 ZX750.1 mono block class D amps. custom box, nice...posting pics next weekend...but all this is wired to the stock head unit. il llet you know how this turns out. but if you hgave some better ideas, im ready

 

He is probably has the sub hooked to the rear channel and just fades it out for level control.