when should u use polyfill?

Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=22330
Printed Date: May 10, 2025 at 8:41 PM

Topic: when should u use polyfill?

Posted By: maxx3616
Subject: when should u use polyfill?
Date Posted: December 04, 2003 at 10:19 AM

i gots some of that acoutic mat...or call polyfill....when and how much should i use?

Replies:

Posted By: forbidden
Date Posted: December 04, 2003 at 1:01 PM

Lightly stuff the box, what kind of box is this, sealed, ported, compound trapezoic flux capacitor slot load or what? and the subs?

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Posted By: Durwood
Date Posted: December 04, 2003 at 1:56 PM

I use polyfill in sealed boxes - about one pound per cubic foot of enclosure space. Polyfill works by absorbing some of the pressure waves from the sub and converting that energy to heat. This makes the box "appear" bigger to the sub. If you have room in your install to make the box as big as you want, you probably don't need polyfill. If you use it, do what Rob suggested and pack it in very lightly, like tufts of cotton candy. You want all the fibers loose and free to vibrate. It won't work if the stuff is clumped back in one corner of the box.

Scott Gardner

Posted By: maxx3616
Date Posted: December 04, 2003 at 3:33 PM

it a sealed....mdf/fiberglass box.

Posted By: Ketel22
Date Posted: December 04, 2003 at 7:12 PM

usually polyfill is used only when your enclosure it too small for the sub. polyfill can create the illusion that the box is up to 20% larger. if your box is only a cuft and you need it to be 1.25 cuft then you would add polyfill. if your box meets the requirements of the sub then i would advise against using polyfill in the box.

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