Stuffing test report

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Just completed an "all things being equal" stuffing test.
.3 cubic foot sealed box with RS-150 driver.
I do not have a scale to measure the exact weight of the stuffing. The "fillness" seems very much the same.
Measured at 6 inches with TrueRTA quick sweep. Not looking for absolutes, but for the difference.

Compared:
Empty box
Dime store poly fill (the slick stuff)
Recycled cotton batting
Long hair wool
Maidsound special poly Acoustastuff that was on sale. (denser)

Empty box:F3 @ 85 Hz, about 1 dB more output from 50 to 200
Polyfill: F3 @ 80 Hz, less smooth below F3.
Cotton: F3 @ 75 Hz, much smoother clear across the spectrum
Wool: F3 @ 75, maybe a tad smoother
Acoustastuff: F3 @ 75 and just about an overlay of the wool.

Conclusion:
10 Hz for a little box is a big deal. 12% 'taint nutun to sneeze at!
Poly is better than nothing, but best left for stuffing craft pillows
Take your pick of the made for box stuffing materials. Maybe the edge goes to the wool, but you are splitting hairs.

Now I know.
 
great little test TVRgeek! I think youre right, no need for a radical test. Has the setup been dismantled? I wouldve liked to see polyfoam in comparison to the BAF wadding tested. I have a feeling, and it is just a gut feeling, that the BAF would be at the bottom of the list.

I once stuffed a small 2 litre bookshelf with teased cottonwool, and a block of foam in the centre of the box. Worked really well. I really have no idea why i didnt do so again. Correction, just remembered-i built vented boxes afterwards, and concentrated on reflective absorption.
 
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Just completed an "all things being equal" stuffing test.
.3 cubic foot sealed box with RS-150 driver.
I do not have a scale to measure the exact weight of the stuffing. The "fillness" seems very much the same.
Measured at 6 inches with TrueRTA quick sweep. Not looking for absolutes, but for the difference.

Compared:
Empty box
Dime store poly fill (the slick stuff)
Recycled cotton batting
Long hair wool
Maidsound special poly Acoustastuff that was on sale. (denser)

Empty box:F3 @ 85 Hz, about 1 dB more output from 50 to 200
Polyfill: F3 @ 80 Hz, less smooth below F3.
Cotton: F3 @ 75 Hz, much smoother clear across the spectrum
Wool: F3 @ 75, maybe a tad smoother
Acoustastuff: F3 @ 75 and just about an overlay of the wool.

Conclusion:
10 Hz for a little box is a big deal. 12% 'taint nutun to sneeze at!
Poly is better than nothing, but best left for stuffing craft pillows
Take your pick of the made for box stuffing materials. Maybe the edge goes to the wool, but you are splitting hairs.

Now I know.

You may have an aversion to fiberglass. If you had used that, you probably would have gotten down into the lower 70's. FG is the best stuffing for closed boxes, hands down. Many studies have shown this. PM me and I'll send you a summary table of a study done by Vance Dickason, author of The Loudspeaker Design Cookbook.

Check out this link to the best closed box site on the planet. I'm 'carlspeak' over there....
Some additional AR4x stuffing info. and off axis response testing - Acoustic Research - The Classic Speaker Pages Discussion Forums
 
SD,
Your PM seems to be off. I can try FG pretty easy. I always was told it was about the worst. When cool enough, I'll get into the attic where I have a roll I have not run out yet.

How can I have an aversion to FG? I did have a TVR for 20 years!

What's a TVR?

Try PM'ng again. I think it's on now. I have LOTS of documents to send. You may want to include your email address. I don't think the PM'ng system can handle a bunch of attachments.
 
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Maybe the edge goes to the wool, but you are splitting hairs.
Oh! Punny you should say that. :D The Bonded Logic cotton batting is really good, I second that.

What's a TVR?
A sportscar. There are other TVR fans on this forum.
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Except that none of those tested UltraTouch which has been shown to be better yet.

dave

Where's the referenced study?

Cotton fiber is pretty large in diameter. Fiber fineness is a key parameter in closed box stuffing performance. I've tried cotton batting sold in craft stores and it wasn't anything special.

As far as wool goes, I've tried Marino wool, pretty much the finest wool and compared it to wool stuffing sold by the speaker builder suppliers and it didn't perfom much better.
 
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This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.