Boxes for 12" Subs, a Tight Fit, Done-ish

[Kyken]

Finished my sub boxes a while back, except I still want to cover them with thin carpet, and bracket them in place.  I wanted to be able to have 2 x 12s, which is overboard I know, and space was tight.  I originally had round boxes in mind, but I could not get a 12" cylinder reliably with kerf cuts in MDF.  I measured and found that I had the clearance, barely, if I cut the corners off of square boxes, so ta-da, octagonal boxes.  The are a little less than ideal in terms of cubic feet, so I added some fiberfill. 

First pic is from behind, in the trunk.  I experimented with different screw locations.
Second pic is from inside of the car.

[MEK-Dangerfield]

Wow!   

 That should knock your fillings loose when you turn it up. Nice job.   

[GreenFishie]

Interesting choice. Were you set on a tube?

Empty sub tubes are pretty easy to find, but if you just wanted to make one ... get a 12in concrete tube form at home depot or any building supply store. It's what we did in the early 90s because we weren't impressed with SAS and their bazooka subs ... powered or otherwise.

One form is good for maybe 4-5 enclosures depending on if you're porting or not. You just have to join some MDF to the ends with gorilla glue after you have attached the hardware you need.

[Kyken]

I did consider that exact thing, I think you or another member mentioned that in passing when I was searching for ideas, but I wanted 3/4" MDF for beefiness.  I almost added internal supports to the boxes I made, but I did not want to decrease the volume any more from what is considered ideal.  Not sure if that much support is needed, but I work with a lot of structural engineers, so I err on the side of too much support.