Acousta-Stuf Polyfill Speaker Cabinet Sound Damping Material 1 lb. Bag

Acousta-Stuf, a synthetic material made from crimped fibers, is an excellent choice for filling or stuffing small enclosures or transmission line cabinets.
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Part # 260-317
  • Higher performance than natural fibers, easier to use than fiberglass
  • Improves bass, tightens midrange, increases dynamics
  • Super-stable, won't decompose, doesn't attract insects
  • No mask or gloves required!

Product Details

Acousta-Stuf Polyfill Speaker Cabinet Sound Damping Material 1 lb. Bag

Acousta-Stuf, a synthetic material made from crimped fibers, is an excellent choice for filling or stuffing small enclosures or transmission line cabinets. Long fiber wool has been a favorite among serious speaker builders but Acousta-stuf is less expensive than long fiber wool and does not have the problem of harboring moths. Acousta-Stuf™ also outperforms Dacron, foam, and fiberglass.

Acousta-Stuf sound absorption damping fiber deepens bass, provides cleaner midrange, and improves the dynamic extension of any speaker system. There are no health hazards with Acousta-Stuf and no mask or gloves are needed when using this product; the melting point is a very high 490°F. Most sealed and vented enclosures require 1/2 lb. of damping material per cubic foot of enclosure. For best results it is recommended to loosely fill the material throughout the enclosure.

Acousta-Stuf Polyfill Speaker Cabinet Sound Damping Material 1 lb. Bag
  • BrandParts Express
  • Part Number260-317
  • UPC844632037382
  • Product CategoryCabinet Damping Material
  • Unit of MeasureEA
  • Product Rating
    (66 Reviews)
  • Weight1 lbs.
  • California Prop 65

    Warning: California residents only. Please note per Proposition 65 that this product may contain chemicals known to the State of California to cause cancer and birth defects or other reproductive harm.

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Acousta-Stuf Polyfill Speaker Cabinet Sound Damping Material 1 lb. Bag
Acousta-Stuf Polyfill Speaker Cabinet Sound Damping Material 1 lb. Bag is rated 4.4545 out of 5 by 66.
Rated 5 out of 5 by from works as expectedAcousta Stuf does a good job on damping. However, the shipping is more expensive than the product.
Date published: 2014-07-29
Rated 5 out of 5 by from Acousta-Stuf PolyfillProduct needs to be fluffed, 1lbs was about 1/2 a pound too much for my two tower speakers. Works well, and the sound is much better!
Date published: 2014-06-25
Rated 4 out of 5 by from Really Helps!I'm happy I bought Acousta-Stuf for my speakers really helped on sound. Just don't over stuff the speakers.
Date published: 2014-06-20
Rated 5 out of 5 by from Good stuff.This stuff does what it is supposed to do.BUT if you buy this by itself, the shipping charge costs more than the product itself.
Date published: 2014-02-22
Rated 5 out of 5 by from Works as advertised!I put this in a pair of sealed enclosure Dahlquist DQ10s I rebuilt and was very happy with the results, firm tight bass. I had a pretty good amount left over from the 5lbs. I bought so I put it my ported Reynaud Offrandes. I'm still evaluating them, but the bass tightened up and smoothed out, less boom. It certainly changed the voicing of the speaker. Not sure if I will leave it in but it definitely does what is is advertised to do.
Date published: 2013-04-12
Rated 5 out of 5 by from Low toneGreat used it to give my bass amp a deeper low tone. My Line 6 bass amp had no filling or damping of any kind, now it has a lower more solid sounding tone
Date published: 2013-03-22
Rated 5 out of 5 by from This stuffing stuff is some good stuff.I used this in a 8" sub. I only used about 1/3 of it. It is a litte clumpy straight out of the bag. Fixed easily. Works well and showed up quicker than expected. All in all a good deal to me.
Date published: 2013-02-19
Rated 5 out of 5 by from Works great!Says what it does, does what it says! (And no itching!)
Date published: 2012-09-03
Rated 5 out of 5 by from AR-3a RestorationAfter opening my 40 year-old AR-3as, I found them filled with glass wool. Any kind of handling generated tiny airborne shards of glass fiber which irritate the eyes and breathing. I had to use goggles, a mask and nitrile gloves. I decided then to try the Acousta-Stuf polyfill to replace the glass. It was a good choice and the results are very satisfactory.It is important to "fluff" this material properly to get the density desired. Using 1/2lb per cubic foot, three pounds just filled my AR-3as perfectly. The sound is as good as the glass, possibly better. It will take long listening to decide. It is certainly safer than the glass.
Date published: 2011-11-11
Rated 5 out of 5 by from No more spikesAfter building a line array box, I noticed a few odd spikes in the speaker so I tried to stuff the box with Polyfill. The difference was immediately clear. There was about a 3 db difference at 40 hz and 100-200 hz smoothed out as well. I didn't just stuff it in the box, instead I made a 1/2" thick mesh and fastened it to all surfaces. I am a firm believer in this stuff now. Grab a bag and see what your speakers are supposed to sound like.
Date published: 2011-11-10
Rated 5 out of 5 by from does what it's supposed tonever use home insulation in speaker cabs. It's a basis-measurement because it's regulated and widely available, only.Try 1/2 " duct fiberglass wrap, dacron (high) loft batting and this stuff to fine tune the cabinet after you have the correct dimensions/shape/volume of the cabinet for the driver that you are useing. There's no magic here. Only good physics and lots of math.. A good speaker cab. might be inexpensive but, only after you have spent money, knowledge and time building it !!
Date published: 2011-09-26
Rated 4 out of 5 by from Poly fill Who?I bought this product for sealed boxes that are going to enclose my new Pioneer components. I haven't used it yet, but it looks far more dense than poly fill. Hopefully, it will outpreform the mentioned product.
Date published: 2011-09-15
Rated 5 out of 5 by from worth the extra $$The midrange compartment on my DIY 3-ways was half stuffed with cheap pillow fiber. Decided to pickup a pound of Acoustastuf with my last PE order to see if it's actually worth it. It totally is! First off, there's a huge difference in a side by side comparison of cheap pillow stuffing to this stuff, Acoustastuf is much much heavier (more dense). Fully stuffed the mid compartments with this and it cleaned up their sound noticeably. There's a chance it's just the placebo effect, but I don't think that's the case! The heavier fibers must stop backwaves a lot more than the feather-lite cheapo pillow stuffing. I'll be using this stuff exclusively for fullrange sealed cabinets from now on, I have yet to try it on my DIY subwoofer.
Date published: 2011-09-14
Rated 5 out of 5 by from Does what I need it to do.I installed a cheap $10 10" sub in part #260-642 without Acousta-Stuf, and it sounded like the cheap $10 sub that it is. I fluffed up a 1lb. bag and stuffed it all in the box, reassembled the sub, and now it sounds more like a $30-$40 sub. Hits are deeper and there is less "buzzing" when turned up to higher volumes.All in all, it's a little spendy, but it is something you can do to improve SQ in a sealed box.
Date published: 2011-07-06
Rated 4 out of 5 by from Extremely versitileThis stuff is great! It makes tuning speakers for dampening so easy; just put in or take out as much as you need to get it to sound right. I've used it in a couple of sets of old Altec Lansing computer speakers (a ported 2.0 and a 2.1 system0. In the 2.1 system I stuffed the sub on the side of the driver up to the magnet and left the other side of the baffle open because of the port. It's a 6 inch sub but now it kicks like my 10 inch!! It totally revived these old computer speakers to sounding like high quality speakers.
Date published: 2011-05-06
Rated 4 out of 5 by from Improved Bass for my Infinity QLS-1I used this for my Infinity QLS-1 and with very good results!I stuffed two and a half pounds of Acousta Stuff in each cabinet and heard a great improvement in the bass !I also used a foam gasket for the woofers to seal the box.I recommend this to anyone wanting to improve their bass.
Date published: 2011-04-12
Rated 5 out of 5 by from Acousta-Stuf Polyfillwell it does it's job well, for the cabinets I put it in was a old Sony 2-way, ported, i have a GRS 8", nice speakers as well, the bass was a lot smoother, tighter, I'm going to get more and try it in a pair of 3-ways I'm replacing the speakers in, & YES With PE speakers.
Date published: 2011-03-21
Rated 5 out of 5 by from Tighter, deeper bass!Really tightened and deepened the bass in my Klipsch Heresy's. After having seen the inside of a pair of Advents stuffed with foam, I decided to try filling my Heresy's. The difference was amazing!
Date published: 2010-06-27
Rated 5 out of 5 by from So Easy A Cave Man Can Do It.Cured all my speaker box ills. Thanks Acousta-Stuf
Date published: 2010-06-14
Rated 4 out of 5 by from Good basic dampingThis filling material does what it is touted to do. I would like to see it be a little less lumpy, however
Date published: 2010-03-21
Rated 3 out of 5 by from Works great if used correctlyTHIS IS NOT A LINER. You are to fluff it up to fill voids, and spaces to tighten up sound in cabs, etc. If you want a liner, and you are rich you should us studio foam. If you are poor you can use fiberglass insulation. This works well, but much precaution should be taken to insure that you don't get fiberglass in your eyes, or underwear(don't ask). For my 4x12 I cut up a $40 egg crate style mattress topper to line the inside. Then FLUFFED up the Acousta-Stuf Polyfill and filled about 3/4 of the cab. Took about 2-2 1/2 lbs. Worked great! Don't forget to buy a new topper for your bed. Didn't sleep very good that night.
Date published: 2010-02-11
Rated 1 out of 5 by from Expensa-StufPurchased and deployed 2 lbs of this product:Pros: - the product performs okay- no protective gear needed for installation/use- comprehensive labeling and MSDS noticeCons: - far too expensive- sonic properties = Mid-Fi, not Hi-Fi- inconsistent material thickness/density- difficult to apply in even layers- inefficient : various sized chunks of material in the bag, forcing the builder to piece/patch together to get adequate surface coverage without wasting material.Bottom line: Expensa-StufFrankly, I expected a better product for that price. Next time, I'll either go the fabric store and buy coarse polyester batting, which in my opinion, sounds almost as good. Or, I'll use fiberglass insulation which has way better sonic properties. Both alternatives COST FAR LESS than Acousta-Stuf. Both alternatives have far more consistent thickness/density. Both alternatives are far easier to install, even considering the well documented itchy fibers of fiberglass.I would not use this product even if someone gave me a bag for free, because it takes so long to achieve an acoustically clean installation.
Date published: 2010-01-15
Rated 5 out of 5 by from Good ValueProduct was as expected, good quality maticulously packaged along with my other items and shipped in an acceptable time frame. Shipping Cost.....Well....Mother always said!!! lol
Date published: 2009-12-19
Rated 5 out of 5 by from The Right Stuff(ing) !!!After using regular polyfill from fabric stores or pillows, fiberglass, foam of various types, and basically any other material I thought would act as cabinet damping material, finally, I tried the real thing: Acousta-Stuf. I bought a few pounds of this with plans to use it in a future project. But, I have a amplified subwoofer as part of my home theater that I just could get a satisfactory sound from. I adjusted the EQ, phase, moved it all over the place.For the heck of it I decided to replace its stuffing with Acousta-Stuf.I could not be more pleased! Wow. What a diference this 'stuff' made.Buy it, use it, and you will be happy that you did.I never thought it would make such a big diferemce in the sound of my subwoofer. The bass is full but much more even with very little in the way of peaks. Very little EQ needed.
Date published: 2009-12-11
Rated 5 out of 5 by from Does what it saysGood product at a great price. Easy to use, no itching or odors. Installs easy, goes where you want it to go.
Date published: 2009-12-04
Rated 5 out of 5 by from Good stuffUsed it many times, and it is a must for any speaker cabinet.
Date published: 2009-09-26
Rated 4 out of 5 by from I am a beleiver nowThis stuff is amazing. It made the bass and mids much tighter. I bought the 1 pound bag on a gamble and it paid off. Now I plan on putting 2.5 lbs in each of my tower speakers and at least a pound in my 10 inch sub. Too bad it will be $55 to do this.
Date published: 2009-08-25
Rated 3 out of 5 by from Try it, you'll like it.This material does make an audible difference in the performance of loudspeaker enclosures. A little experimentation is necessary in order to 'dial-in' the right sound, but I view that as a positive learning experience. In small amounts, the price is reasonable, but it will add up quick if you need several bags.
Date published: 2009-08-10
Rated 3 out of 5 by from What a difference! Acousta-stuffI built a small bass guitar speaker,and it sounded terrible until I used the Acousta-stuff
Date published: 2009-06-11
Rated 5 out of 5 by from best fill everworks better than wool, fiberglass or any other fill i have tried in a sealed box.
Date published: 2009-06-05
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Product Q&A

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Acousta-Stuf Polyfill Speaker Cabinet Sound Damping Material 1 lb. Bag

i have a speaker box

that is 2't x 13.5"w X 15"d and its all sealed its got 2-SELENIUM 6.5" and a SELENIUM -ST 200 supper tweeter in it. should i use this to bring the sound down? if so how many bags?
Asked by: big white
A good rule of thumb is about a half pound of stuffing per cubic foot of volume in the elcosure. Assuming those are external dimensions, you have around 2.5 cubic feet of total airspace.
Answered by: MattP
Date published: 2013-02-22

What is the denier, fiber type and cross-sectional shape of the fibers?

Asked by: Beacon of knowledge
The cross-sectional area and shape of this is known as 'trifilar', or most like the Mitsubishi logo. This is why it stays put and how you place it as it holds itself well.
Answered by: Wolfy
Date published: 2013-05-31

Does acousta-stuf increase the Vas?

I am creating a portable dock and i would like to cut back on the massive size required by the manufacturer. Is using acousta-stuf a way around using the full required Vas? I am using 3 inch tang band full range speakers and they each require .05 cu. ft. which seems to be quite a lot. And if i do use the acousta-stuf can I port the enclosure? Will the acousta-stuff damped the bass output?
Asked by: BeetzyBoy
Technically yes but it also lowers the "Q" of the enclosure which makes the woofer act like it is in a slightly larger box. The best way to take up volume in an enclosure is with small blocks of wood or anything with solid mass like this.
Answered by: MattP
Date published: 2014-08-06

What is the best way to fluff Acousta-Stuf?

Asked by: Moose68Bash
Acousta Stuf comes in a bag and is pretty compacted together. All you have to do is pull apart the fibers as well as you can. Think about how you fluff a pillow.
Answered by: MattP
Date published: 2013-04-17

how man cubic inches/feet per 1lb bag, please?

Asked by: hapiniregon
That depends on how much you tease it apart, the concept of volume doesn't really apply. Speakers typically specify damping by weight. One of the kit speakers I had came with four bags of the stuff, each measured out by weight for different compartments.
Answered by: AlonzoTG
Date published: 2013-01-25
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