no sound from subwoofer

So, I have a 2009 Acura TL technology package and decided to put in an aftermarket 12" subwoofer but since I'm keeping the factory head unit, I bought a loc and wired it to my rear deck speakers L and R but when I play music the subwoofer doesn't have any sound, but it has power and has a good...

I came across this 15 and it was cheap so I just bought it without hooking a multi meter to it or testing it, and Dude was willing to trade l back if need be, (i’ve made my fair share of mistakes in the past in which I have learned from and have a damn near full proof system to where I don’t...