[nodiak]

I found this locally:

http://www.intelligentinsulation.com/pdfs/IIG-406.pdf

http://www.specjm.com/pdf/iig416.pdf?PHPSESSID=69ef6ec247a4f6eb751324fd3ac06d33

It's $45 for three 2' x 4' sheets that are 4" thick. I have to go there to see which type it is to be able to tell the density. Hoping it is 4-6 lb/ft3, and not 8 or 12. I think it's the "Safing"  IIG-403, 4lb. I'll check.
Does this look good for corner traps?

Thanks, Don

[bpape]

If you can only go 4" thick, are going to straddle corners, and this is at least 6lb or 8lb density, it's probably the best way to go.

If they carry IIG and they can get it, look for IB1280.

Bryan

[nodiak]

Bryan,
For the corner trap idea which works lower - IIB1280 vs. the 5.5" Cotton you stock? (The price is the same).
And which would have better broadband absorption? I realize it may not be the same one for each effect.

Don

[JoshK]

Don that looks good to me....

For bass traps though you might need to make a circle out of it in a 18" or thereabouts.  This will make a decent bass trap.   Stuff the center...even better.

[nodiak]

Hi Josh,
I'm making two front corner traps, using the design of angling 24" wide framed insulation across the corners. So i won't be making those cylinder types. I hear they work well, hoping this type does too.
I don't know if you saw the closet trap thread but if that is a good idea I'd use the same material on those, which are in the rear corners. The closets would provide 30" depth behind the insulation so it seems would trap deep bass. But I'm inexperienced at this. There is definitely bass lift in the closets waiting to be swallowed up.
If possible the same material used will be good for broadband absorption too.
The other part of the plan is to do broadband on side walls of front and rear corners, and 1st reflection points (walls and ceiling). I'll get a 1" or 2" material for this.

Don

[fajimr]

I'm making two front corner traps, using the design of angling 24" wide framed insulation across the corners.

don,  I did the same thing with 4" 6 lb. ottawa fiber mineral fiber.  I just asked the guy at the insulation place which was the closest to the owens corning 705 (?, I think that is the right one as the 703 is used for 1st reflections).  They worked out great!!!

here is a link to my gallery pic.  http://www.audiocircle.com/index.php?action=gallery;area=browse;album=832&pos=1

I've got some 3lb that I hope to build into 1st reflection traps also.. in the near future.  good luck!

[bpape]

They're just different.  The thicker material will go a bit deeper and has a hump in absorbtion around 250Hz which some rooms like - some don't - but you can balance with other things.

The mineral wool is the most space efficient.   It won't go quite as low but it's pretty close.

The best solution would be 6" of IB1240

Bryan

[nodiak]

fajimr,
thanks for the photos. That's inspiring if that panel controls bass issues to some degree for your room. Does it also do anything for reflections?
Don

[fajimr]

don

the traps certainly did a job taming the bass and, in the process, allowing the mids and highs to come out (or at least that is how it seemed to me). 

I'm not so sure what they did for reflections and the soundstage (what the first reflection traps affect more, if I understand correctly).  The sound is much more lifelike but not more spacious and separate...  hopefully when I get the 1st reflection traps built and installed, I'll be able to report back about that.  I do have wood floors and plaster walls so I imagine that I have more reflection issues than others....

one note- when I was looking for the pine to build my bass traps, the friend I was with strongly suggested that I get the better quality pine and then sand and stain it.  I was thinking that it wouldn't matter much but in the end I was happy with the quality of the look so I would suggest the same.

good luck and keep us posted on your progress
jim