when adding filling in my box, do I glue it to the walls or do I just stuff it with 1 1/2 lbs of it? does anyone know any tips or things that you do to improve your enclosure? I have a twin box with two RF 10" 200w max and a RF 250.

 

Don't glue it. You want it to be able to 'move around'. There are several theories to how the polyfill works but the most scientifically sound is that it acts to reduce vibrations of the air waves by converting that energy into heat energy. The polyfill vibrates, heats up, disipates the soundwaves. Unless you have a really accurate scale it is difficult to weigh polyfill. If you have test equipment, which most of us don't, you can keep adding polyfill till you get the Q you want. Otherwise keep adding it till you get the SQ you want. Once you add too much you will start haveing less deep bass and more pronounced midbass - similar to not haveing any polyfill. Other than that you want the box to be as stiff and sturdy as possible. Use plenty of bracing. If you have a wooden box I recomend a cote of good waterproof paint on the inside. I use the rubberized undercoating stuff that can be bought at Wal-Mart or any auto parts store. This seals all of the wood joints as well as the wood fibers. Should help give a tighter sound.

 

Where can I buy this polyfill stuff and what does it look like. I just made a custom fitted box for my Maxima and need some. How much does this stuff go for?

 

You can find polyfill at any fabric craft store. Its in a bag and it looks just like a large mass of cotton ***** only its just polyester fiber. I got mine for under $3.00

 

Now another question- what type of polyfill??? there were 2 choices of this stuff at the store, the regular polyfill where pull it apart to stuff it and there is the kind that comes in sheets where apperantly you unroll it and cut It. I bought the "regular" kind that comes in one big piece.
So does it really matter? or is polyfill just polyfill?

 

You can get it at places as Nismo stated. It's also sold at Wal-Mart and the like. I can't seem to locate my copy of Vance ****inson so I won't quote the best densities or the best materials for the purpose. If you plan to build more than one enclosure or if you have friends who might be building one I recommend going to Lowes or Home Depot. Go to the insulation section. Find an Owens Corning insulation called Myraflex. This is a polyester fiber specifacally designed as an insulating material with more bends per inch and a softer texture than the stuff you will get at a fabric store. A single roll should be less than $10. It will probably contain 5-10 lbs of a material that has a higher R-value than fiberglass. You can use some extra to stuff the rear quarter panels. And even fill large ziplock bags to put it in the doors. The loose material could get caught in the window mechanism and it also does not work well when wet.

 

When I make a stupid suggestion, "Don't glue it", I have to admit it. In a perfect world it wouldn't be needed. But this world is far from perfect. Your enclosure will be subjected to vibration not only from the moving sub but also from the rolling, twisting ride. This and other factors may cause the fill material to settle. To help alleviate this you can use some spray adhesive on the walls of the enclosure to keep the polyfill spread evenly. The number of individual fibers held in place will be insignificant compared to the total fill material. As an alternative to using the spray adhesive you can stuff the box prior to the full cure of the undercoating spray. Use it as a sealer and a glue. Allow the box to sit in a warm(68F) and dry room for 24-72 hours before installing the subs.