HEY, i just bought my 2002 tl type s and i wanted to install an amp (rockford bd1000) and 2 12s(haven't bought them yet) without changing the HU, i know i have to buy an LOC but what i want to know is how do u install in, my car has an stock amp so do i tap the wires before the stck amp or after also do i tap the wires in the stock subwoofer or speakers, PLease HELP, really confused

 

Well, if you are installing subs, I would tap your LOC in at the factory sub's wire leads (after the amp)..

 

I Gotta disagree, If you use the speaker lines after the amp, you'll get more noise, poor sound and you'll be limited to whatever frequency response the factory crossover/amp was made for.
I'd tap into the line level before the factory amp and use a good LOC with a crossover, preferably with a remote sub control.