How to Connect to Factory HU
 

I have XM Radio, Onstar, and the upgraded pioneer system. If I added a Sub to a Class D Mono Amp and some extra speakers to another amp, what is needed to connect them to the factory HU.

P.S. I am new to amps and everything if you can't already tell. Does the Class D amp connect to the Extra Speaker amp. And how do I run my Factory HU to only use the Factory Speakers when I dont want all of the power of the extra sub and speakers.

Please Respond if anyone knows any answers to these questions. Anything will help

You can also post on my other thread if you would like:
https://www.chevyhhr.net/forums/audio-video-17/speaker-amp-pre-setup-questions-9048/

why keep the factory unit? it is a rip off for what you could get in an aftermarket deck. there are adapters to keep your onstar(about $150-225). what sub amp and 4 channel r u looking at? i saw your last thread and being an installer by trade we would charge anywhere from 1200-2k for a system of that nature and thats just for a decent entry-mid level system.

I was thinking the sub amp would be Earthquakes Powerhouse PH2000W/D1 and the speaker amp be Earthquakes TNT T2000W/4. Again i am not sure about the compatibilities of these amps. Installing the entire system would probably be less expensive because my uncle works at Livernois Auto Shop and he has a buddy who is amazing at setting systems up. Really though I may just keep the factory speakers and sub the same, and instead of adding a sub, maybe just make a folddown of speakers off the tailgate for when i am at tailgates. In respect to the HU, I like the appearence of the HU but I cant afford to add the expense of a new one, at least right now. Maybe Pioneers AVIC-D3.

Just replace it.. the factory HU is garbage... speaking from experience

I liked the factory HU, still got it in my wife's with no plans on changing it out. IMO, for most people it's fine. If not for a great deal of hassles, i wouldn't have changed mine (LONG story)