[randytsuch]

All,
  I have to thank people who pointed me to this mineral wool alternative. Previously I have been looking all over Houston trying to find Owens Corning and Knauff fiberglass board but unsuccessful.

  I have managed to find IIG mineral wool product this morning though. The question I have is given this IIG MinWool-1200 pipe has density of 8lb, What would be the minimum thickness that I should get?

  And do I need different thickness for 1st reflection point vs using as bass trap at 4 corners?

  Thank you very much.
  RV

Here is the data sheet for minwool 1200 industrial board
http://www.intelligentinsulation.com/pdfs/IIG-402.pdf?PHPSESSID=1be46ead235481095251b22095821b88

I would think this is more appropriate for making 1st reflection absorbers, and it comes in different densities, and thicknesses.  I am a newbie to this stuff, so I don't know which combination is better, but I did see a post recently where it cost was a factor.  I guess how thick you are willing to make your trap is another factor.

BTW, the data sheet I linked to has acoustical data, which is not in the pipe data sheets, so that may help you decide.

Good luck
Randy

[bpape]

The 8lb material you described will work well for a bass absober in a 4" thickness.

For reflection points, you should try to find something less dense, like 3 or 4.5lb.  The 8lb can actually reflect upper mids and highs when the waves hit at a shallow angle like they do on side wall reflection points.

[95bcwh]

Thanks guys.. one last question, is there a particular type of fabric that's good for wrapping up these Mineral Wool materials?

Jon Risch mentioned that he prefers Burlap, but I thought Burlaps have some large gap between the threads hence it's not good enough to prevent the mineral wool from coming off.

I went to Walmart and saw some 100% Polyster fabric, thicker than most fabric and have no gap at all, is this a good choice?

[gonefishin]

Thanks guys.. one last question, is there a particular type of fabric that's good for wrapping up these Mineral Wool materials?

Jon Risch mentioned that he prefers Burlap, but I thought Burlaps have some large gap between the threads hence it's not good enough to prevent the mineral wool from coming off.

I went to Walmart and saw some 100% Polyster fabric, thicker than most fabric and have no gap at all, is this a good choice?

   I'd also be interested in the responses that you get.  I used a non-sheen loose interlocking weave fabric for mine.  But the difficulties of seeing the sheen or the differences in the weave (how restrictive they are) is very difficult to get a goo picture without looking, seeing, feeling the fabric itself.  

   I could never understand the burlap thing...especially considering that todays burlap is actually not real burlap(created from jute, hemp or flax fibers).  Most of todays "burlaps" are a desnse, yet open weave of 100% cotton.  

   either way...you've got some nice options out there...and DIY could be a nice way to go.

  dan

[Scott F.]

This is just an opinion but I think you should use either an open weave cotton or wool. Think about something on the lines of cheese cloth. My pea brain reasons that cotton and wool provide a (very) minor amount absorption and will also allow the sound waves to freely pass into your mineral wool. If you go with a synthetic blend such as polyester, with it's composition and weave density, you will likely get reflections off its surface. .... but then again, I' might be all wet.

[randytsuch]

This is just an opinion but I think you should use either an open weave cotton or wool. Think about something on the lines of cheese cloth. My pea brain reasons that cotton and wool provide a (very) minor amount absorption and will also allow the sound waves to freely pass into your mineral wool. If you go with a synthetic blend such as polyester, with it's composition and weave density, you will likely get reflections off its surface. .... but then again, I' might be all wet.

Hi Scott,
I am a newbie to this stuff, but I have read other posts, and articles that same the same thing.  Stay away from dense materials for this application, as they will reflect the higher frequencies.  

The point of this covering is to let the sound in, but keep the insulation particles from coming out.  Some of the how to articles recommend covering the insulation with batting first, then with a loose fabric cover.

I am getting ready to make some room treatments, and was thinking burlap, the fabric you use for speaker covers, or the Guilford of Maine cloth.  Since the first two are locally available, I will probably go with one of them.

Randy

[95bcwh]

To Scott, Ryan and all the experts:
  I was wondering, when you covered up these quad shaped MinWools pipes with fabric, what's the quickest way to join the fabric together?  I can only think of using a stapler or a duct tape? I don't want to get into sewing the fabric together, and I figure it's too much work to build a wooden frame to hold these quad shaped pipes.

 Thanks
  RV

[bpape]

If you're worried about fiber shedding, you can simply use a thin layer of poly batting around the wool before wrapping it.  Using a tight woven cloth can cause some reflecting of high frequencies in some cases.  This allows the open weave for good absorbtion but the batting is still absorbant enough to not change the HF absorbtion characteristics of the absorber in general.

GOM is a good choice but people still use a layer of batting sometimes.  

Another option is lightweight muslin.  It's relatively transparent, cheap, easy to dye to whatever color you want, etc.  Just be sure to apply the appropriate fire retardant to it for safety (this applies to any non fire rated fabric - GOM is already fire rated BTW).