Im going to build a box for a 12" sub, i plan on using MDF board 3/4 thick. What do you use to seal the joints in the box to help keep it air tight?

 

silicone caulk should work fine. just make sure you let it cure before you mount your woofer into the box. best thing to do is keep your joints to zero clearance, ie don't leave any gaps. where are you gonna put the box?

 

i think you could also counter sink the holes and then use wood screws to hold the box together , but dont quote me on that.

 

I just built a box for 2 10's. I used 3/4" MDF and short drywall screws to hold the box together, using some liquid nails on the seams will help give an even better hold and a help to get a more airtight seal. 1 tube of silicone was more than enough to seal the gaps after the box was assembeled and it works excellent. As motown suggested don't forget to let the silicone dry overnight before you install your sub. Best of luck to you. Hope to see some pics when ur done.

 

I just built my box, 3/4" MDF, held together with lots of liquid nails and 2.5" drywall screws.

 

wow, 2.5 " screws seems a bit excessive

i'm going to try to build my own box as well, but will be using
1 5/8" drywall screws.

yeah, i've read the product to use is liquid nails, both to glue the MDF together as well as fill the seams inside the box.

 

Yeah I use 2"+ screws and liquid nails, which rocks, I used the same combination to build ramps, so that says how strong it is.

Its also a good idea to go on the inside corners with sealing caulk (but let it dry before you install the sub.

Straigt cuts help a LOT. You can pick up a $100 Ryobi 10" tablesaw Home Depot which is worth its weight in gold for tihs kind of stuff...

 

yeah, x 2 on the cheap table saw. money well spent IMO. 2 inch screws should be fine. but if you really wanna be slick, buy yourself an air stapler. they're used for making furniture. 2" staples and you're done with your box in like half an hour. i miss working at a well-equiped shop...

 

i say use 1-5/8" drywall screws... space them out every 2"... wood glue between the boards.... silicone all the seams.. inside and out... i would also counter sink the holes to make it flush...

 

I actually work at home depot so i made all my cuts on their lumber saws.....everything is very straight. The box is .85 cubic feet and its for one rockford 12" sub which i plan on fitting under the rear strut bar. What do you guys use to carpet the box? I cant seem to find black carpet, or anything that will match the black interior.

 

try a fabric store.... i know of places here in chicago... don't know much about a nation wide deal.... try to find automotive carpet or even a textured vinyl would look nice