View Full Version : Built my box too big. Help!

12-02-2006, 08:56 PM
So I built my box too big and the internal volume turned out to about 1.8 cf. The box is sealed and I need it to around 1.15 cf. I am leaving the box the dimensions it is since it fits just the way I wanted it to. My question is can I use expanding foam to fill up the extra airspace. I am going to make a square block and when it dries I will cut it too the right size and glue it in the box. I was going to use wood but I want to keep weight down.

Thanks for any help in advance.

12-02-2006, 09:04 PM
I would leave it alone more then likely will sound better at that size and have a lil more lowend.

12-02-2006, 09:08 PM
The sub was previously in a 1.10 box and it sounded great. It had an amazing lowend. I listen to mainly rock and metal so I like to keep it tight.

12-02-2006, 09:15 PM
just try it @ 1.8 and if it sounds bad make it smaller.

12-02-2006, 09:17 PM
I am trying to avoind making a new one since I had to use someone elses tools to build this one. I am just curious if this would be an ok way to fill up the airspace. Or if any one has any other ideas on how to fill up the airspace and stay light.

12-02-2006, 10:31 PM
Try it out as it is. If you don't like it, glue some pieces of 2x4s in the enclosure. That will help brace it as well as take up some space.

12-02-2006, 10:34 PM
Try it out as it is. If you don't like it, glue some pieces of 2x4s in the enclosure. That will help brace it as well as take up some space.

x2. i did that exact same thing a couple years ago and adding some bracing worked fine.

12-03-2006, 10:56 AM
Like I said in the original post I am trying to stay away from using wood so I can keep weight down. If the expanding foam will not work can someone let me know so I can try and figure something new out?


12-03-2006, 10:58 AM
what are the demensions? sounds like you may be measuring external demensions....

12-03-2006, 11:05 AM
I used the calculator on the12volt.com and it takes into account for wood thickness.
The dimesnions are 12.75 deep bottom 16 tall 5.75 top depth 30.75 wide and the front face is 17.5 made with 3/4 mdf.

12-03-2006, 11:10 AM
Dude a couple pieces of 2x4 is not going to be that heavy, hell a whole board isnt that **** heavy, you probably wont notice hardly a difference in the size of the box but just try it how it is now and if you dont like it put in some 2x4's, foam would prolly work but its gonna be a lot harder to calculate the airspace of rather than a 2x4.

12-03-2006, 11:15 AM
I am actually going to make one big block of foam and cut it to fit in the ends of the box. The peices will be pretty much square and easy to measure and figure out the volume of the pieces I use.

Thanks for the good input everyone.

12-03-2006, 11:15 AM
yep, 2x4's is where its at.

12-03-2006, 11:19 AM
just get a sheet of that thick, rigid foam from home depot and cut to size with a knife.....but i would try it at the current size to see if you like first

12-03-2006, 04:03 PM
wow, audio people really have trouble listening sometimes...

I had similer problems myself, first off reguardless of what "they" say Bigger is not better for what you want to do.

Ive even found 1cu to be rather large for one 12"

If you listen to rock stay with a small sealed you will be happy you did, I love my Brahma in .75 cu personally and listen to rock,country

second I like the Home depot foam idea, it might be alright to use the spray foam but I havent tried it, just make sure its dense foam that you cant blow through, Good luck with it bro.

12-03-2006, 08:11 PM
Thanks guys for the input. I have had the sub in a larger box, about 1.5 and it sounded sloppy. As soon as the foam dries I will see how dense it is. When the whole can is sprayed it takes much longer than the four hours stated on the can.

12-04-2006, 12:42 AM
ohhhhhh my