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View Full Version : A few quick ?'s about sealed boxes



BaTooK
12-24-2003, 08:03 AM
About to build a sealed box and thought I'd get a few things straight first. Okay so the 10" subs I bought say to use .6-1 ft^3 per sub for a sealed box. Why this range? What is the difference of the 2 extremes (bigger=louder? lower?)

Ok so I want to put 2 of these subs in a sealed box. Should I separate the box to make 2 chambers with a board sealed in the middle, or just build a box that has a total volume of 2 cub. ft? Does this matter/ what is the difference?

Finally, is it a good idea to use polyfill in a sealed box? What is this used for?

Thanks for any help.

Trixter
12-24-2003, 10:41 AM
About to build a sealed box and thought I'd get a few things straight first. Okay so the 10" subs I bought say to use .6-1 ft^3 per sub for a sealed box. Why this range? What is the difference of the 2 extremes (bigger=louder? lower?)

The larger the box the lower the freq. it will be tuned to. Also the larger the box the less power it takes to move the sub; the sub becomes more efficient. On the flip side, if you plan on sticking a lot of power to the sub (rms value or higher) you can by making a smaller box.


Ok so I want to put 2 of these subs in a sealed box. Should I separate the box to make 2 chambers with a board sealed in the middle, or just build a box that has a total volume of 2 cub. ft? Does this matter/ what is the difference?

If you go with a sealed box it is best to seperate the chambers. By doing so you are preventing the chances of ruining a sub if the other one blows. If a sub blows and the chambers are open to each other, the blown sub will act as a passive and could damage the good one...because you now have twice as much air space.


Finally, is it a good idea to use polyfill in a sealed box? What is this used for?

Thanks for any help.

Polyfil is used in sealed boxes to "increase" the internal volume of a box. It slows down the back waves of the sub so it acts like it's in a larger box. It is ideal if you don't have enough room to build the box to the size you want. About 1lb per cu' should be used as a rule of thumb.