First time box builder questions

JRX7

Member
2001-04-08 6:24 am
LI, NY
I'm about to start building an enclosure for my 8" Kicker CompVR. It's going to be a triangular shaped wedge, here are the proposed specs for the box:

8"Hx12"Dx28"W using 3/4" MDF.

This will give me an internal volume of 0.525 cubic feet. My driver is designed to work well within 0.4 to 0.6 cubic feet so this seems OK.
With those exterior dimensions I have come up with these sizes to cut the wood:

12"x26.5" for the base
7.25"x26.5" for the front
14.5"x26.5" for the back
2 - 8"x12"x14.5" pieces for the sides.

Did I do all the math right? I am going to mitre cut the piece for the back at 45 degree angles to it will mate with the front and the base. I am using 1" wood screws to secure the sides while the wood glue sets, and was told to coat the edges where the pieces meet with some rubberized undercoating to help seal them. Anything seem wrong with my design? Can anyone provide me with some tips or advice before I start? Thanks in advance.
 
Hello, you should use WinISD to design your box because I think your maths are wrong :)


If interior dimensions are 8"x12"x28" = 2688 cubic inches.
12"x12"x12" = 1728 cubic inches (1 cubic feet)
So, 2688 / 1728 = 1.56 cubic feet.

For your box, the internal volume is:
12"x26.5"x7.25" = 2305.5 cubic inches
12"x26.5"x(14.5"-7.25") = 2305.5 / 2 = 1152.75
Interior volume = 2305.5 + 1152.75 = 3458.25 cubic inches
3458.25 / 12x12x12 = 2 cubic feet.

Typical box between 0.4 and 0.6 is:
10"x10"x10" = 0.579 cubic feet.

Regards,
 
couple of comments from woodwork side

Okay, rather than approach the audio side of your questions, I'm going to look at the woodwork side of it. First, have you ever worked with MDF before? Its VERY dusty stuff, and can be difficult to work with. Make sure you pre-drill ALL of your screw holes first, before screwing in. Also, you should look into using screws designed for MDF instead of just plain wood screws. (Yes, there actually are screws specifically for MDF, and it does make a difference) If you want to use wood screws, use ones with a coarse thread, not a fine thread.

As to the "rubberized coating", simply caulk all of the interior joints to make sure its air-tight. Other than that, have fun with it!!!
 
FrankDIY said:
Hello, you should use WinISD to design your box because I think your maths are wrong :)


If interior dimensions are 8"x12"x28" = 2688 cubic inches.
12"x12"x12" = 1728 cubic inches (1 cubic feet)
So, 2688 / 1728 = 1.56 cubic feet.

For your box, the internal volume is:
12"x26.5"x7.25" = 2305.5 cubic inches
12"x26.5"x(14.5"-7.25") = 2305.5 / 2 = 1152.75
Interior volume = 2305.5 + 1152.75 = 3458.25 cubic inches
3458.25 / 12x12x12 = 2 cubic feet.

Typical box between 0.4 and 0.6 is:
10"x10"x10" = 0.579 cubic feet.

Regards,
Note that he said the box was a wedge, not a rectangular prism.