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expanding foam

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=112891
Printed Date: May 16, 2024 at 12:17 PM


Topic: expanding foam

Posted By: bemendozer
Subject: expanding foam
Date Posted: April 03, 2009 at 1:30 PM

Hello

Am abit baffled about expanding foam and sub enclosures. I was told today that instead of using speaker box wadding in the sub box I should use expanding foam. So heres my question if I build a box that is 2CuFt then fill hald with expanding foam is this not going to make the box 1CuFt instead? I don't see how the foam with work like wadding.

Any body got an opinion on this?




Replies:

Posted By: ckeeler
Date Posted: April 03, 2009 at 3:04 PM
if you fill your box halfway with expandable foam, by the time its done expanding you will have zero airspace left as is will fill the entire box! lol. seriously though, use polyfill, not expandable foam.




Posted By: haemphyst
Date Posted: April 03, 2009 at 3:18 PM
Expanding foam is a "closed cell" product. This is why you use it to fill gaps in window frames or ledges and the like. It is "non-permeable" to moving air. You wouln't ever want to fill (and by "fill", I mean insert into) an enclosure with it, unless you were actually using it to adjust the volume of the enclosure, due to it's being too large. Stuffing works the opposite way - it actually makes the driver think it's in a larger volume than it is (but only up to about a 10% gain).

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."





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