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Discussion Starter · #1 ·
After reading various negative comments on using poly fiber fill to stuff enclosures to bring qtc down and make the driver think it is in a larger enclosure I am starting to think I should use something else.

What are people's thoughts on fiber fill and what is the best stuff to use. Excuse the pun!

cheers

Graham
 

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Yes, where are you reading negative comments? I recommend using poly fill.

And by the way, it does not make the driver "think" the enclosure is larger, it effectively makes the enclosure larger by increasing the density and complexity of air flow paths inside the enclosure.
 

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Is there a "Best" material to use for fill? (sub will be sealed) My mains are filled with fiberglass in the woofer chamber and lambs wool (DIY upgrade) for the mids and tweets. I read a review on Parts Express where the author said Acousta-Stuf Polyfill worked much better than your basic polyfill and comments on other boards that claim fiberglass is better then ployfill.
 

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Discussion Starter · #6 ·
Hi guys,

I bought this stuff.

http://www.worldofwool.co.uk/products.php?cat=68

I have read positive and negative comments but I have seen some people use sheet type fill to line the walls of the sub and some use like what I have to stuff the middle of the enclosure. I wasn't sure if it was there was any advantages/disadvantages of lining the wall of filling the middle of the enclosure.

cheers


Graham
 

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Is there a "Best" material to use for fill? (sub will be sealed) My mains are filled with fiberglass in the woofer chamber and lambs wool (DIY upgrade) for the mids and tweets. I read a review on Parts Express where the author said Acousta-Stuf Polyfill worked much better than your basic polyfill and comments on other boards that claim fiberglass is better then ployfill.
I believe it is wool, then fiberglass, specialty fill, and then regular pollyfill. The difference is not that great though. I have seen it wool, fiberglass, and polly tested somewhere, but I can't remember where.
 

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Hi guys,

I bought this stuff.

http://www.worldofwool.co.uk/products.php?cat=68

I have read positive and negative comments but I have seen some people use sheet type fill to line the walls of the sub and some use like what I have to stuff the middle of the enclosure. I wasn't sure if it was there was any advantages/disadvantages of lining the wall of filling the middle of the enclosure.

cheers


Graham
That will work fine.

With subs you stuff a sealed enclosure, and line a vented one. Some people choose to just line a sealed sub instead of stuffing it, to each his own. :T

If you are talking full range speakers, you can just add some lining the wall behind the driver to help dampen rear wave reflections. You could also stuff a sealed, and completely line a vented enclosure.
 

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I personally will always stuff a sealed enclosure.

One day I was building a pair of subs (Peerless XXLS 12's) for home audio and was mounting the drivers. I had bought pollyfill to try and did a stupid but effective test. I did some shouting/low humming into the enclosure and listened for the decay. Then stuffed it and tried again.

The stuffed enclosure had less echo and reverberation. I thought about how an echo/reverb would negatively influence the rear of the cone of a speaker and decided after that to always stuff my enclosures. How much? Well that depends on the application.
 

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Discussion Starter · #13 ·
Is there a fine line of adding too much. I am going to be building 2 8 cu ft sealed subs in a couple of weeks so in theory it will need 8lbs of fiber fill per sub which equates to about 3.5kg in each.

So if you add 3, is that not enough and if you add 4 is that too much. You see what I mean. Is there a rough gauge to go by to stop you adding too much.

cheers

Graham
 

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The line isn't as fine as you might think and the ratio isn't always the same. It's stuff to taste really. It can be different for different setups too depending on how well you've hit the enclosure requirements.
 

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Discussion Starter · #15 ·
My subs will have a qtc of 0.83 so to bring it down more what would be the suggestion if the average is to add 1lb per 1 cu ft. Would adding an extra 1 kg of fiber fill bring it down much more.

The reason it is quite high is because they are FI Q18's and they normally need a massive box but I don't have room.

cheers
Graham
 

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The differences reported by some people using various materials to stuff enclosures has no impact on the sound quality, only on the effectiveness of the materials per ounce added. All fiber stuffing will cause the same effects on the enclosure: physics is physics. Generally 16 ounces of fill per cubic foot of volume is considered 100% "stuffed."

As an aside I have had some bad results using woofers with vented pole pieces and fiberglass house insulation. The fibers in house insulation are friable and can get into the woofer motor, causing eventual failure. At least this is what happened in my installation. I recommend using polyester material (or wool) as it is far less friable.
 

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Discussion Starter · #17 ·
I just had some fiber fill get caught in one of my t nuts when I went to take out my driver. Really stuffed me up as the t nut popped out from the inside and as I tried undo the screw all it did was tangle the fiber fill in it. Real Nightmare.

Oh! and it happened twice. Boy did I sware!


cheers


Graham
 

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The differences reported by some people using various materials to stuff enclosures has no impact on the sound quality, only on the effectiveness of the materials per ounce added. All fiber stuffing will cause the same effects on the enclosure: physics is physics. Generally 16 ounces of fill per cubic foot of volume is considered 100% "stuffed."

As an aside I have had some bad results using woofers with vented pole pieces and fiberglass house insulation. The fibers in house insulation are friable and can get into the woofer motor, causing eventual failure. At least this is what happened in my installation. I recommend using polyester material (or wool) as it is far less friable.
I think it goes without saying. Make sure you wrap anything you stuff with. No reason to risk it.

I suggest you use pillows it's just easier that way.
 

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The differences reported by some people using various materials to stuff enclosures has no impact on the sound quality, only on the effectiveness of the materials per ounce added. All fiber stuffing will cause the same effects on the enclosure: physics is physics. Generally 16 ounces of fill per cubic foot of volume is considered 100% "stuffed."

As an aside I have had some bad results using woofers with vented pole pieces and fiberglass house insulation. The fibers in house insulation are friable and can get into the woofer motor, causing eventual failure. At least this is what happened in my installation. I recommend using polyester material (or wool) as it is far less friable.
Yeah, the pantyhose trick works quite well that someone mentioned above. I've done this quite a few times. Kinda interesting walking into the store and scoping out the pantyhose section.
 
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