[Ron]

 I recently built a pair of GR Research AV-3 speakers using No Rez damping material on the interior walls per Danny's recommendation.Really glad that I did. No Rez works very well in damping out resonance. In addition, the construction plans also specified using either loose poly fill or fiberglass insulation, so I opted for the poly fill. Even though the speakers sounded great using the poly fill,I decided to experiment by replacing it with 3 ounces of Acousta-Stuf damping material in each speaker to see if it made any difference.To my ears,the AV-3's do sound better with the Acousta-Stuf compared to poly fill. Bass seems to be tighter,cleaner,and better defined.Also,the midrange seems to be smoother and more natural sounding.I would like to know if anyone else has tried Acousta-Stuf.If so,your opinion.

[Bill Baker]

Hello Ron,

 I have been using Acousta Stuff for years. When I originally built my GR Research OB-7 speakers, I used a minimum amount of it, about 1/2 lb. in the bass section (the bass enclosure is sealed in the OB-7). I wanted to start with the minimum amount so I could experiment with adding more.

 Last week I took the speakers apart to apply more oil finish and install more fill and ended up with about 1.25 lbs in each cabinet and things were noticeably better. The mid bass was tighter and upper bass frequencies were more refined.

 I have no doubt you noticed an improvement with the Acousta Stuff. I still have about 20 lbs of normal poly fill that I no longer use since going strictly with the Acousta Stuff. Maybe my wife can make some pillows or something

[darienlake]

How much Acousta-Stuf would you recommend for an LS-6 with no-rez already installed.  I'm thinking about 1/2 to 3/4 lb per driver section.  Does 4 to 5lbs per speaker sound like the appropriate amount?

Appreciate any input.

Thanks
Liv

[Ron]

 The recommended amount of Acousti-Stuf is normally 1/2 lb ( 8 ounces) per cu-ft of internal volume assuming no other damping material is being used. Since your LS-6's already have No-Rez installed,I would suggest using approximately 4 ounces per cu-ft to start and then adjust  the amount as required until it sounds best to you. I have found it helpful to use ounce kitchen scales to measure out the Acousti-Stuf so that you can place equal amounts in each woofer comparment.Remember too that when using Acosti-Stuf,it needs to be teased out the same way as if you were using long fiber wool.Also,be sure to keep both the No-Rez and the Acousti-Stuf at least 1-1/2 inches away from the back of the woofer.Hope this info is helpful to you.

[darienlake]

Ron... thanks for the help.