2010 Sierra Extended Cab

[Mason Moody]

I have a 2010 GMC Sierra extended cab and I was looking to do 8 audio legion 12s. Does anybody have any idea if this will work. It’s gonna be tight and I know it has been done in other extended cabs but I don’t know about my model. Any feedback would be helpful, thanks.

[Joe X]

Whats the model of the subs and the max dimensions of a box?

[JerryWilliamson]

Audio Legion has several (I mean *several*! 😆 ) subwoofer product series -- like eleven! --. For sake of example, say you are going with the Armada Series 12". Recommended box volume is 2 cu. ft. per speaker *plus you will need surface area for the port. That is 16 cu. ft minimum in the back of the cab. A total enclosure size would be something like 60" wide x 30" high x 16" deep. The concern would obviously be the width.

In my Pilot, the maximum width I can do in the back is 55" or so unless I want to take out the OEM interior panels and go full custom that way (which is a one month project in and of itself), 55" is my limit.

With a height of 30" (assuming you are removing the rear seats) you *also* will be losing at least some of your rear window visibility. So what I would do is simply get out your tape measure and measure the width especially. If you are short of 60" in terms of what will fit, you can have the enclosure point the outer subs (this is a 4 wide by 2 high layout) in at 45 degrees which will save you possibly 4-5 inches. But that is a very complex design which will require top notch fabrication skills not to mention some decent tools (including a table saw). Yes, it will be tight no matter which approach you take.

If you do a 3 wide by 2 high layout (6 subs total), your enclosure dimensions then would be 45" wide x 30" high x 16"  deep and I will guarantee you that configuration will fit in just about any truck or full size SUV. So the next question is do you absolutely need eight? Check out Steve's Escalade build on YouTube and that monster box he built (needed a fork lift to install it since it weighed several hundred pounds) used six 12" B2's. The enclosure looked like around 52" wide.

Depending on your amplifier configuration, a six sub layout would likely result in a 2.66 ohm load (instead of 4 ohm load) so going from eight to six subs would save you space AND the lower impedance would still give you a higher power output with just the six. Just make sure your amplifiers are *at* *least* 2-ohm stable. I always recommend doubling the minimum impedance the amp can handle to allow the amp to run cooler AND to extend the life of the amp. It also further minimizes distortion which will improve sound quality. Clipping will kill tweeters and mids. With subs, you might get away with it but the system at max volume level will still sound like garbage. Get a distortion detector (recommend the SMD DD-1) throughout the entire tuning process to guarantee you can get maximum performance without damaging your speakers (or the amp) via clipping. Good luck!