Hey,this is what I want to do; My 04 QC 4x4 has an Infinity Sound system with an amp mounted behind the dash, tweeters in the pillows and speakers in the doors. I am wanting to install aftermarket speakers in doors (Polk Audio 6x9 coax and 6 1/2 coax, using factory head unit and amp). My question is, is there a crossover built in the factory amp or is it located elsewhere? I have been told that there was a crossover and that there wasn't. Needless to say I am confused. Any help would be greatly appreciated.

 

I have an 04 QC 2500 with the Infinity as well. I replaced all of the door speakers on a whim. The front doors only get the bass, the highs are directed towards the tweets in the dash. Not sure where the crossover is. The rear speakers receive 100% of the frequencies...

My next move is to replace the head unit, and rewire the whole thing...

 

Hey, I must apologize, my truck is an 03 instead of an 04. I guess I had a brainfa** when I was writing. Sorry about that.