What is 'polyfill' stuffing?

[JoeM]

Im building a project that requires polyfill stuffing but here (Australia) I've never seen it. I have an idea it may be some form of cieling insulation in the US? Can anyone point me to some info or a pic so I can find an equivilent downunder. Pink batts? Fiberglass? Tontine?
Thanks.

[Nuuk]

It's the sort of stuff they put in pillows, quilts and sleeping bags to provide insulation!

If you can buy cheap pillows, they are a good source!

[infinia]

Hi
Pollyfill = polyester fiber filling. Think fabric store or hobby store, usually for stuffing pillows and such.

[HiFiNutNut]

JoeM,

Get it at Spotlight - your best and cheapest choice.

A second choice is Jaycar. I bought some from them.



Hi Guys,

I am looking for wool material stuffing. Where can I find it in Australia? This is kind of funny since Australia is a wool exporter.

I am sure I don't have to spend big dollars to build a wool quilt for speaker stuffing. I need quite a bit of them.

Any advice?


Regards,
Bill

[Volenti]

Probably your best bet would be loose fill wool insulation, it comes insect and fire treated. Most insulation companies should be able to supply it.

[jackinnj]

Originally posted by JoeM
Im building a project that requires polyfill stuffing but here (Australia) I've never seen it. I have an idea it may be some form of cieling insulation in the US? Can anyone point me to some info or a pic so I can find an equivilent downunder. Pink batts? Fiberglass? Tontine?
Thanks.

you can also get it a a pet food store -- the polyfill is used in fish-tank filters as the removable media.

[dnsey]

Probably your best bet would be loose fill wool insulation

Wool has different properties - superior in many ways, but the results will not be as expected.

[infinia]

Don't forget the mothballs if you use wool or other animal furs.

[HiFiNutNut]

Thanks.

Different materials have different ability to damp resonance at different frequencies and by no means they are linear.

I think polyfill is rather hopeless at low frequencies and wool would be better.

I saw a link long time ago listing the effectiveness of different materials at different frequencies and I have lost that link. If anybody has one please kindly provide it here.

I want to damp the woofer resonance at around 160Hz. I may try ringing up an insulation company.

Regards,
Bill

[Svante]

Filling material has two effects:

1. It introduces an acoustic resistance which attenuates acoustic resonances ("standing waves").

2. It makes the compression/decompression of air inside the box isothermal, rather than adiabatic; this has the effect that the box appears to have an up to 40% larger volume.

Different materials have different properties. Some materials, like polyfill mainly has the (2) property, others like fiberglass does both (1) and (2). If an assembly instruction suggests polyfill, then using fiberglass will give a response different from the intended. Polyfill is good for bass-reflex subwoofers with a sufficiently low and steep crossover frequency, where standing waves isn't a problem. If it is replaced with fiberglass there is a great chance that the frequency response drops several dB at low frequencies.