Replacing speakers and sub and amp

[19964x4HOE]

I have a 2001 Tahoe LT with a NON-Bose stereo system with onstar. It has the factory 8" sub in the rear and i am guessing it is all amp powered. But i am wondering if all the speakers are powered by the amp or is just the sub powered by the amp? So my next question is if i decide to replace the speakers do i have the do anything special? or will they hook up just fine?
My next question is if i decide to replace the factory sub and put a little amp in place of the factory one to power the aftermarket sub what do i have to do to bypass the factory amp? or can i use the wires that power that sub? where is the sub located?

If anyone can give me some info please let me know Thank you

 

[Jaxon1023]

Amp to everything is behind glove box. I just ran wires from my aftermarket radio to the fosgate speakers the po installed and ran off the amp. Sounds so much better.

 

[19964x4HOE]

so if i replace my door speakers i cant jsut hook them up to the stock wiring?

---------- Post added at 07:25 PM ---------- Previous post was at 07:22 PM ----------

or are you saying that you ran wires form the headunit to the speakers and had the wires from the amp going to the speakers to? i ahve stock headunit and wanna keep stock headunit i am just wondering about replacing the speakers to make it sound a little bit better

 

[Jaxon1023]

In your case I would just add new speakers. When I got the tahoe it had an aftermarket radio and aftermarket speakers. They sounded like crap off the stock amp so I wired them today to the new radio I bought.

 

[The 'ER]

After market speakers will work. Just might have some fitment issues. My Sony's did not cooperate so I trimmed and then installed with self tapping screws with heads painted to match the door so no one knows.

 

[19964x4HOE]

painted to match the door? arent they behind the stock grill on the door panel anyways?

---------- Post added at 11:05 PM ---------- Previous post was at 11:05 PM ----------

In your case I would just add new speakers. When I got the tahoe it had an aftermarket radio and aftermarket speakers. They sounded like crap off the stock amp so I wired them today to the new radio I bought.

how did they sound like crap? like distorted? or barely any sound? under powereD?

 

[Jaxon1023]

I have 6 1/2 Rockford fosgates front and back. Previous owner installed them. Backs fit fine. Front he had to screw into door frame but can't see it behind the grill.