Light weight sub enclosures


Active Member
Nov 11, 2002
New England
Well, I pulled all my stereo crap out of my GT, but I'm hesitating on putting it in my Cobra. The main thing is the weight, those MDF boxes are heavy. So I got to thinking: when I worked in car audio years ago, we frequently put plexiglass windows in high end sub enclosers. Assuming it's lighter than MDF, is there any reason why I couldn't build a complete box out of plexi? I know it's stronger than MDF, so 3/4" may not even be nesessary, saving even more weight. What I don't know is how a plexiglass box would sound compared to the traditional MDF. Thunderforms are made from ABS, I'd think it could only sound better than that, right? Anyone with [more experience than me] in the business know why this would or wouldn't work? Would it be just as heavy? Or, do you have any other suggestions for a lighter material than MDF to make my box out of?
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plexi is not that light, unless your using something as thin as 3/8". For serious bass, you want at least 1/2" and the plexy cant flex, thats lost energy or dB. You might save a few pounds, but probably not much if the box is built and braced correctly
Well, I have audio carpet that's a perfect match for my interior, so I was planning to carpet whatever it ends up being. I never did fiberglass work though, so I'd have to farm it out... I was hoping for a material I can work with myself. I've built hundreds of boxes, but all out of MDF. Unfortunately.

Mines pretty light.. Just use an efficient sub and small amp to keep it light...


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Too late, I already have the components. It's a system I built and have been using for years. The only thing I may do is go from two 12's to one, since I always felt the bass was a bit overkill for me. I'm not buying any new components though, and what I have is heavy. That's why I want to save weight wherever possible, and the only place I can see to do it is in the sub box.
It will never see the track. It makes a difference in how the car handles in daily driving, and I just don't want to pork this car out in general like the last one... which was actually about that much too heavy for the specific rate coilovers in the rear anyway. I still haven't done anything. I did decided to go with a single Boston SPG555. 1000 watts, 26lbs and requires less than a cubic foot of air space. This should save me well over 50lbs from my two Alpine R12s, and I should be able to get a model specific Boston enclosure as well.
That boston sub that you are considering requires a very deep box with it having a 8-3/16" mounting depth. Are you trying to save space also? I was going to tell you to build the sub box in the tire well out of fiberglass and ditch the spare, but the sub you want to run is probably too deep. You can still however get some fiberglassing ideas from this site. Fiberglass is probably the lightest and is not that hard to work with if you have patience and a bisic understanding of what you want to create. Check this out and tell me what you think

Ithink you can pull this off if you tried.