stuffing a sub with polyfill? (1 Viewer)

[tom_furman]

my friend has an audiosource 15" sub that sounds a bit "boomy" to me...we did some searching and on audioreview.com alot of the people said they stuffed teir sub with polyfill sheets and that made a world of difference.
now exactly how do you do that? just unscrew the bottom of the sub, and line all the inside walls with the polyfill sheets? is there more to that or am i missing a step?

 

[Saurav]

That's pretty much it, based on what I've been able to gather. Polyfill isn't very good for you if you breathe it in, basically, you don't really want it in your environment. So make sure you keep it away from the port opening, and some people put some sort of netting over the polyfill and staple the netting to the cabinet, to keep the stuff from moving around. Also, the best way to get into the sub varies - for instance, for the Sony SA-WM40, the easiest way is from the front, by removing the driver.

 

[John Garcia]

You can either get it in sheet or loose. I prefer the sheet, since you just cut it to size (and it doesn't tend to "shed"). I sprayed it with some "tack" spray and just stuck it to the sides, with one staple in the top corners. Basically, it slows down the back wave within the sub, and minimizes the reflections inside. Don't go crazy though, since you don't neeed much to do the job.
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[Edited last by John Garcia on August 15, 2001 at 12:34 PM]

 

[tom_furman]

whats a good store where i can swing in and pick some up?

 

[Saurav]

Any fabric or craft supply store. I found it in the pillow-making section, but that wasn't the polyfill sheets, it was a big chunk of the stuff.

 

[John Garcia]

I got mine at a

craft store. They had the pillow making stuff, and the sheet stuff too. Most fabric stores will likely only have the pillow stuffing, but it's worth a shot. The loose stuff does a better job, because it tends to be more dense, but the sheet stuff is easier to use, if you can find it.
[Edited last by John Garcia on August 15, 2001 at 02:57 PM]

 

[Scott Quick]

Before you run out and buy some poly fill, is your sub a ported design or a sealed design. My bets are a ported design if its a LFE sub. If so, you want to avoid poly fill and use sheets of acoustic foam. The cheapest way to get "acoustic" foam is to go to kmart or walmart to the bedding section, and grab a foam mattress pad... yes really. Line the rear, top, sides, and bottom. NOT the rear of the baffle (the inside surface of where the driver is mounted).
The poly fill messes up the tuning frequency in ported boxes. If sealed, then go ahead and use poly stuffing. Most often, its also found in the bedding section, usually pillow stuffing. Also, at arts/crafts stores. Line the same surfaces as mentioned above for above with poly stuffing. The lining with poly should be at least 2 inches thick. If the bass is still to "boomy," you can add a big wad of stuffing in the middle of the box. For lining the edges, rule of thumb is a half pound/cubic foot.
HTH,
Scott
>

 

[John Garcia]

One last thought has nothing to do with poly fill, and that is: Have you tried different locations for your sub and is it calibrated to match the rest of your system's reference level? These two things can have a significant effect, particularly placement.
Yes, if your sub is ported, this will help only marginally, and will certainly affect the tuning of the port.