speaker upgrade on 08 sierra

[Mikes08GMC]

Hello guys im new to the forum and i just bought a 08 gmc sierra Z-71! I love it! Anyways i wanted to upgrade the speakers in the doors and the back. I have an extended cab with all 4 doors that open. I have read on Crutchfield that some of the speakers require a speaker bracket since the openings in the rear are square? Anybody help me out on this on? I plan on keeping the stock deck since im keeping the Sirrus radio.

Thanks
Mike

 

[SonofaSierra02]

I have an 02 with the same thing. I put JL speakers in all of my doors (I also ordered from Crutchfield) and I did need a bracket for the rears. I believe I just put 4.5 inch round speakers in and used an adapter plate to bolt up to the rectangle hole. Hope this helps