Trying to figure out this audio issue

The black wire under your front seat most likely is the door speakers. If you wanted to, pop your door panel and see if there is a matching 16 awg there. If so, that would be awesome.

If you are looking for a good 4 channel amp, the Soundqubed S4-100 is solid. Rated at 100 watts per channel and has pass band cross overs. It has been dyno'd (find it on youtube) and was shown to put out 150 watts per channel.

Thats insane from a company like SQ for that price and reputation.

$150
Pass band crossover, thats unheard of on budget amps.
Potential of 150 watts per channel, also unheard of on a budget amp.

Just throwing that out there cause they're a great company to deal with.

 

Agreed. You have plenty of options that will basically just pop right in without any hassle.

 

I love myhttps://soundqubed.com/product-tag/hds2-108/

 

Havent heard them yet but when they came out i would of bought some but i was happy with the hds212.

Rocking an American bass xr 12d2 now. Was a tough call between that and the hds312.1