So i'm just starting to treat my 'mixing' room - aka the spare room... and have purchased a pack of Unsulco Polycoustic insulation and some Auralex Mopads for the task.
I've seen people cover DIY rockwool treatments with various cloth materials to keep the fibres from floating around, and for the most part these are ok, but tend to look a bit too DIY in some cases... And thats ok for basments and corners where the visitors never wander. But what if your mixing space is somwhere in your home thats near the main living area? Where people will see your stuff?
I know some wont care too much... and think nothing else matters but the sound. It's a very valid point.
But you guys need to meet my wife.heh
So after that little rant, here is what I'm thinking.
1. Box-frame the batts (std Batt size is 1160mm x 580mm x 90thick) using 90mm x 35mm framing timber.
2. Macenite backing.
3. Glue the batts inside the frame
4. cover the whole thing (frame and all, if you so choose) in some cool fabrics.
The idea being that thee things will actually look like painted canvas', or close enough not to look cheap and crappy (remember were attempting to 1. keep the wife happy, and 2. get her involved in the process...)
So assuming that the 'looks good' criteria has been addressed (yeah yeah yeah, I know it should be the LAST thing on the list), will this actually work?
Do the sides of the insulation need to be exposed to be effective? Will the wooden sides of teh box-frame impede the absorbtion propoerties of the Polycoustic Batts? What about fabric types for covering? Are there types that should NOT be used for acoustic reasons (excepting the obvious... like sheet metal!!)
I plan to make up 7 or 8 of these things and hang them off the walls in the mixing room. Should look killer. But will they be effective, as I've described?
Cheers narco. The batts are acoustic specific and are as dense as a really dense thing.
then my guess it they're not the right ones? Actually I'm serious, the stuff they market here in New Zealand as "acoustic" batts are only slightly more dense than normal thermal insulation. To get the real dense stuff I had to go insulation specialists and get stuff that is made for insulating furnaces. When I mentioned it was for acoustics they tried to sell me the "acoustic" stuff which wasn't suitable. So watch out for that.
I took some pointers from the John Sayers and built these 2x4 Panels that might give you some ideas. If you were to use OC 703 or equiv. then your fastening methods could change since its rigid & easier to handle. I used muslin fabric which alone in the end held my insulation in place.
Also, I think it is important to distinguish between acoustic panels, and gobos.
If you want gobos, you need something to stop the sound, ie, the masonite back you mentioned originally (though I'd use something thicker than masonite, ie, plywood, MDF, or even sheetrock). Put absorption around that, and it will do a good job of stopping sound down to a certain point in frequency.
Without the back (masonite or whatever), the sound will travel through the absorber some, but you will get more low end absorption. This is what you want to do with your corner panels, if you put a back on them they won't absorb nearly as much low end (since the low end will "go around" the gobos rather than "go through" the absorbers).
Would a deeper frame with the insulation held at the front work? Also is this gap just for lower frequencies or just a general rule for absorption?
The general rule of thumb is that you space the absorbation panels away from the wall the same distance as they are thick (a quarter of the wave length from the wall with a panel that is a quarter of the wave length thick) to get the best performance. This sets the lower cutoff frequency. The gap apply mostly for lower to mid frequencies since the panel usually is thick enough to dampen the higher frequencies on itself.