Originally posted by nerdling
WC, cool, where are the caps in a car stereo installed?
Always across 12V powersupply side, on the wire between battery and headunit.
(off topic)
You never put powercaps across the speaker wires (hey, its also coil + magnet & it moves...!), but if you don't run crossovers between tweeter and woofer then putting signal caps can do some basic filtering for you.