If my car is wired for a 6 disc CD pioneer player that sits in my trunk, does that mean it's wired for subwoofers?
Not necessarily. It will have power and signal back to the deck. To be wired for subs you need the amp and amp wiring. Usually a large gauge positive with fuse from the battery, large gauge neg, remote on (from the deck) and a set of RCA's or high level inputs (sound signal from the deck to the amp). Then the subs get wired to the amp. Most of the time the amps are mounted in the trunk but some people do put them under the seat.
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