Polk Audio MM1540

Very Durable - Polk makes great speakers!

I own a 2005 GMC crew cab and wasn't too happy with the bass from four ported 9" subs. The bass was very deep but way too boomy for my taste. So, before I purchased this speaker as a sealed box replacement, I modeled it in a sealed box design using AJboxdesigner which is free off the net and it modeled very well. I also chose it for the efficiency. If my memory is correct, Polk recommends ~1.5 cu ft min. but I gave it just over 2 cu ft using as much space as possible behind the rear seat for a lower Qts of around 0.8. I filled the box loosely with lightly pulled fiberglass insulation. After some fine tuning on my Alpine 9861 DVD in dash with an PXA-H701 audio processor, I was very happy with the overall sound of the bass. If you own a earlier chevy or GMC crew cab truck as I do, the box design is very difficult to fit this speaker and I probably should have chosen three of the MM 10s or MM 12s instead. Yes, this 15" speaker is somewhat of a shallow woofer but the front extends out more than I thought which made the sub box tricky to build and fit this speaker as you have to recess it on the front box baffle 1/2" and if you aren't careful, teh rear magnet will hit the back of the box. My only other complaint is that I wished the speaker was in a diecast basket instead of plastic but that would have increased the overall cost of the speaker considerably.