quick polyfill question

[ajm 10+ year member]

Ive been looking to put some poly fill in my box because the airspace seems to be quite small for what I need but never did because I didnt want to bother with stopping it from blowing out of the ports etc. So the other day I went to pick some up for my FG speaker pods and noticed they had some polyfill in what looked like a roll that rolled out to sheets that were X" wide X inches tall and about 1/2" thick. Rather than loosly stuffing polyfill in the box would it be possible to just buy some of this "sheet polyfill" and spray the inside of the box with some spray glue and line the inside of the box with it?

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[Volenti 10+ year member]

The sheet polyfill will work the same as a similar amount of the loose variety.

 

[thai_creeper 10+ year member]

is that more expensive? i think you can put chicken wire or something over your port to stop the other kind if its cheaper

 

[azbass 5,000+ posts]

dont bother putting poly fill in a ported box. if the box is too small. then you would have to rebuild it.

 

[phantom240 5,000+ posts]

dont bother putting poly fill in a ported box. if the box is too small. then you would have to rebuild it.

x2

 

[ajm 10+ year member]

Im not goin against what you guys are saying about "no polyfill in a ported box" but if thats the case how come kicker puts it in theirs. Just curious. Not tryin to make some sort of smartass remark saying youre wrong....Im guessing just to make the sound "smoother"?

 

[Volenti 10+ year member]

Polyfill in an enclosure (be it sealed, vented or whatever) damps resonance to varing degrees at all frequencies and directly absorbs sound at higher frequencies, I consider the thermal effects of fill (making the enclosure appear larger to the driver) to be largely miss-understood and a minor component of the overall effect.

Since vented enclosures use resonance to increase ouput adding fill to one will decrease the output at the tuning frequency, this can be benificial if the enclosure is too small or tuned to high causing a hump in the response.