Buzzing from sub?, I'm getting an annoying buzz with my new custom sealed box Options

[Noahwhite2014]

So I made a sealed box that takes up the inside of the spare tire well and has a false floor baffle flush with the rear seats in the down position. The volume on the interior is around 2.85 cubic feet and there is cushion foam lining the floor pan in the back. The whole box is bolted down to the spare tire tie down hole and that is also the ground point I'm using for the amp. Here's a picture of it.

Looks great and sounds great, but at certain frequencies I get a buzz from my plastics in the back. I believe it's also buzzing the bumper and license plate bezel (not the license plate itself since it has a rubber "anti vibration" frame.

Anyone have a good way to quiet that crap down? Lol

[Box]

Not all 15's have terrible response, of course a 10" or the like will ultimately be quicker but it's not going to move as much air and won't reproduce lower frequencies as well. That's why you use both as smaller woofers take care of higher frequencies and the attack, and the larger woofers take care of the lower frequencies. Of course the crossovers aren't so clear cut, but you get the best of both worlds that way.

This post has been edited by Box: May 3, 2015 - 12:59 PM