Stuck, Factory HU with aftermarket Amps

[Bikeboy80]

Background:

2001 Yukon XL with non Bose, premium sound with sub

I have been working on putting in my amps and new speakers. I am planing on keeping the factory HU. I have a hi/lo converter to splice into the system but am having a tough time figuring where to do it. The factory amp seems to be making it complicated.

I was planing on splicing in to the speaker wires at the head unit but there seems to be common - lines for the front and rear pairs, I'm not sure how to hook to those.

Should I be picking up the signal at the factory amp? Before or after it?

I do have new speaker wire run from the amps out to the doors.

Also, by doing all of this will I lose the functionality of the rear entertainment console?

 

[el_flores]

Just need to pick up the signal at the factory amp, on the output side, after the amp.

 

[Bikeboy80]

So it won't harm anything to an amped signal through the hi/lo converter and then through other amps. I just want to make sure, thanks.

 

[el_flores]

No, not at all. Actually, that's where it has to come from
As for the entertainment system, it shouldn't be affected, unless you're tapping into that wiring for some reason.