Alternative absorbent acoustic material?


I finally read the owner’s manual that came with a pair of speakers I bought last spring (Revel M126Be) and there is a a couple of paragraphs that talk about treatment materials. Revel states that: "There are numerous options for absorbent material. None are superior to low-cost fiberglass." And it goes on to say that "It is important to use absorbers that are at least 4 inches thick, to avoid altering the spectral response of the loudspeakers." It also says that "Sculpted foam is less efficient" and needs to be "at least 8 inches thick."

I assume that the low cost fiberglass that Revel is referring to is the insulation that comes on a roll that is available from, for example, Lowes? Has anyone tried this, and if so how did it work out?

 

immatthewj

I don't believe that's what they are talking about about it isn't very dense.  Panels made of "fiberboard " is what's generally used.  Mineral wool panels are also an option.  Lots of YouTube videos about it.

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The other posters are correct re: Owen’s Corning 703.

Of course, any mineral wool/rockwool that is high density is fine (i.e., Rockwool (100kg/m3 or higher).

The reason to use other materials is sometimes rockwool can absorb too much or you specifically want a frequency range to not be absorbed.

Or, more likely, you don’t want to work with rockwool, which is a PIA to deal with, mildly dangerous if you are an idiot, and can really make a mess.

I heard a room at a shop that was extensively treated with Dow Corning fiberglass panels with Dow Corning supervising the design/installation.  This room, at a local audio store was intended to showcase such treatment.  The result, to my ears was odd sounding and too dry and dead sounding.  Musi9c was clear and detailed, but sort of lacking in liveliness and energy.  To me this was excessive damping, but, I have no idea what a lesser level of treatment would sound like.

In most rooms a combination of absorption and diffusion will result in the most pleasing acoustics. Too much absorption can result in a dead sounding room which is not pleasant to be in, let alone listen to music in. GIK website has lots of info. Their SlatFusors combine absorption and diffusion.

I went down this road recently and have done a fair amount of research on the subject but by no means am I an expert.  A few things I walked away with.  1.  It depends on the size of your room.  My room is pretty small, so it is recommended to trap as much Bass as you can.  2.  4" minimum is required to capture much base at all and it doesn't discriminate, so you need to use some sort of deflector so that it doesn't absorb all the mid and higher frequency (which is what makes your room sound dead 3.  there is very little difference between Rockwool, Fiberglass insulation and the different densities of those products.  

I made some 8' corner base traps using 2' x 4' x 7 1/2" that I found at Lowe's.  Generally the big box stores don't carry much in the 2' wide size.  It's usually the 15.25" x 3 1/2" size which fits between standard wall studs which is a little shy on what you need for depth.  I opted to be that from ATS as mentioned above.  

Thanks for the input and the clarification on the Dow Corning 703.  I did some searches and I think I am going to play around with some of that.

When I built my panels I got Rockwool and 703 from my local insulation supply business at about 40% less than the price from online suppliers. 

@mashif +1 for using local insulation distributors. Couple years ago purchased a case of twelve for around $135.00. Tried to get a current quote but the guy went home for the weekend. So it can’t be much more than that today. 

I built 28 panels, polycylindrical diffusers, and bass traps out of the Rockwool Safe & Sound from Lowe’s. Works brilliantly. However, Menards has a cheaper mineral wool, Johns Manville Sound & Fire Block, that is the exact same thing.

Basotect(click)....way more efficient than any of the ATS and GIK materials....and waaay more cheaper. It’s used in trains, plains, industry and probably (90% chance) in your car’s headliner.
And ehm rockwool, mineral wool and other fiberglass insulation materials are soo 1980....I thought we’ve already evolved from the olden days. devil

I’ve used about two cubic meter to treat my living room.

Super easy to use, and, more important...no need to change your shirt !! wink