You tap into it at a speaker line. Then it outputs to an amp. Some amps have it built in and you would get some taps and run speaker wire from a speaker to the amp and attach it to the speaker inputs. It will convert it on board the amp.
So I can tap in like where the rear door speakers come into the pillar behind the trim? And I have to do one left and one right right?
This is what I bought for my sequoia but never installed. I havent decided if I want to put it in my Honda or the burb.
Alpine Electronics PWE-S8 Restyle Compact Powered 8-Inch Subwoofer https://www.amazon.com/dp/B00OYGGMXK/ref=cm_sw_r_cp_apa_i_ZG4sCbEAQWE1Z
It has built in speaker level inputs.
Is this something that is "all in one" so i can just tap into the speaker wires and run the power and grounds for the amp?