Is it safe to put polyfil in a relatively small box? Wouldn't it create extra heat by being close to the magnet?

 

mb1,

Oh contare, Polyfil which is usually a polyester, is used extensively
in boxes to make small boxes appear acoustically larger, Now, if it was dense packed then you might have a problem but loosely filled box will experience no problems.

dc

 

I'm getting a sealed box with a 1.75cuf of volume per sub. Thats not much space to play around with behind the sub. So I just wanted to know if polyfill would be dangerous since the sealed box can't dissipitate heat.

 

which sub are you going with? my sub takes less than a cubic foot of air space.. what's the spec for your sub? (the enclosure specs)

 

Unless you have a HUGE magnet, I don't think you'd have a problem w/a 1.75cu ft box. My enclosure is 1cu ft for a 12" with a beefy magnet, and I still put a good amount of polyfill in there.

 

im running two 12" HE2's in a sealed box thats 1.0 per sub, and i stuffed each chamber with polyfill up to the magnets. And yes i got a lil deeper bas using it.

Ant

 

The rule of thumb is supposed to be something like 1 pound of polyfill per sq ft of air space.

 

by the way, where is polyfil sold?

 

well I was told that you can go to your local Wally world or a fabric store to get it but I got mine from 'Stealen's' big brother Crutchfield. $8.00 a pound i think.

 

partsexpress.com has it for 8.50 a lb

 

Another thing to consider doing when using polyfill. I bought my polyfill from a retail crafts store. It's sold by the yard, and I bought a bunch of it. When I went to install it, I saw something funny.... my box cracks weren't sealed all the way. I took a hot-glue gun and proceeded to fill all the seals that weren't visible (the ones where the magnets are). Sure, it took about 30-60 minutes to do that for a 2-12" sub box. Then I took the polyfill, and hot-glued it to the sides, bottom, and top of the box. I cut each piece to the exact dimension of the location it was to be glued. That way, each crack was sealed with 2 pieces of polyfill, not 1. I glued all the pieces together, and even put pieces on the top, only leaving holes for the ports. So in essence, my entire box is polyfilled.

Another thing (on top of the last one) to consider was something else I tried. Most pre-made boxes are covered in carpet that is glued to the box. That glue breaks down over time and causes bubbles in the carpet. So to make sure that the front of the box is sealed from the back of the box, you can use that little foam tape that comes with your subs, or you can do what I did. Go to your local home repair store and buy some DENSE weatherstripping tape. Apply it to the back rim of your subs so that it's between the sub and the box. This makes for an airtight seal between the sub and the box. Then screw the sub in like normal.

The sound difference was NIGHT and DAY. No more distortion, no more vibration, and no more rattles from the box. Now, the rattles from the car is a completely different story.

 

Every box I've made I've used polyfill (polyester). Always found it at my local fabric store. My suggestion is to buy the fluffy stuff you make pillows out of (not the sheets) and fill the box up between 1/2 and 3/4 full and then use a staple gun to staple a few places down to the back and sides of the box. Then just re-fluff it in a few places. Never had a problem. If you don't pick it apart all the way it all pretty much stays together. Just minimize your handling of it when you put it in and you will be fine.

Tony

 

Instead of foam weatherstripping, try rope caulk. Because air can pass through open cell foam rubber. Thus the term, open cell.

 

Hey guys, It's been a while,,,,,hope all is well.

Anyway, my take on polyfill is this. I have built a few boxes over my 15 yrs or so playin around with this audio hobby....(some say obsession..hehe ), and I have used it in every box I have built. I use the same rule of thumb mentioned above by redmax, 1 lb. per cubic foot of air space. Yes, I feel that it makes a difference. I have read places that using it can make the box "sound" like it is .1 (1/10th)cubic foot bigger than it really is. Whether or not that is correct, I can't tell ya,,,, but I do use it and I have heard differences in boxes with and without.

I at one time bought mine from Crutchfield too, but I have since grown in knowledge and numbers of bills to pay...hehe,,,so I now get it from local cloth stores for like $2-$4 for a 1lb bag. They sell it in roll form also for like lining boxes if you wish. I have bought really cheap pillows at dollar stores and such for like $1-$2 each and they have the same stuffing. I have actually stapled house insulation in boxes before as an emergency tactic with very good results. Of course I stapled the paper side to the box,,,with the insulation facing into the box.

Well, that's enough babbling,,,,,whichever way you go,,,,Good Luck!!

DMAN