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.
.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.
Another interesting test, in Swedish though but tests stuffing in a tube:
http://www.faktiskt.se/modules.php?name=Forums&file=viewtopic&t=40658
http://www.faktiskt.se/modules.php?name=Forums&file=viewtopic&t=40658
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.
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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Another interesting test, in Swedish though but tests stuffing in a tube:
http://www.faktiskt.se/modules.php?name=Forums&file=viewtopic&t=40658
Google has a built in translator. Just copy and paste the URL address of the swedish thread into Google's search window. Hit search and you'll see one of the hits is the swedish thread and over to the right the word translate. Click on that.......
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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Oh! Punny you should say that. The Bonded Logic cotton batting is really good, I second that.Maybe the edge goes to the wool, but you are splitting hairs.
A sportscar. There are other TVR fans on this forum.What's a TVR?
Long hair wool
Just got back from the Sannich Agricultural Fair where we got the opportunity to "make" long haired sheep's wool.
dave
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.
Except that none of those tested UltraTouch which has been shown to be better yet.
dave
Except that none of those tested UltraTouch which has been shown to be better yet.
dave
You mean this? http://www.bondedlogic.com/
You say TVR, and I think of Granturas or Tuscans.
A 289 version of one of those scared the crap out of me more than once.
dave
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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