Originally Posted by
HCSGuy
So, just for clarification, you are trying to use the speaker level subwoofer output from an OEM/stock audio system to feed into an aftermarket amplifier and subwoofer, correct? I also assume that the subwoofer amp you are using does not have speaker level inputs - RCA only. If so, you will first need to get a speaker level to RCA converter - very common at car audio shops, Crutchfield, etc. Do a Google search and you’ll find them. Once you connect that, you can use an RCA Y adaptor backwards to sum the two signals to a single mono RCA, or your amp may have this capability built in. One warning - if you use the speaker to RCA adaptor and wire one of the speaker wires out of phase, then combine them to mono, the left and right speaker wire feeds will cancel each other and you’ll get nothing, so if you get nothing, try reversing the phase of one pair. Hope this helps