ceiling treatment and diffusor questions

W

wannabecomedeat

New member
Hey, I just finished treating my room with owen's corning 703, 4 bass traps, 4 2" pannels and 4 1" pannels. Now it's time for the ceiling. If i go with the owen's corning solution, it will cost be as much as the treatment I have done from now (350$ CAN). I saw in another post someone got 6 pieces of 4" mineral wool from home depot or something like that for 50$CAN. At that price it would cost 100$ MAX to treat the ceiling.

What's the "gauge" of mineral wool for this purpose? as an example, if you buy fluffy, you'll have choice between r28, r42, etc. What is the one to ask for mineral wool?

I'll also be building 2 diffusers like this one in 2 weeks:
http://www.pmerecords.com/Diffusor.cfm
(I know some say diffusors aren't much useful, but the look will be awesome :D )
Which kind of glue should I use?

many thanks again!
 
The Roxul stuff (& most mineral wool products I've seen) are graded by density. In the US, that's pounds per cubic foot (pcf) (I guess kg/m/\3 elsewhere). Roxul 40 is 4pcf, Roxul 80 is 8pcf, etc. Delta/Rockwool company uses a similar system (e.g. Delta-8 is 8pcf).
 
6pcf and 8pcf have quite similar absorption, with the 8pcf being slightly better in the bass. However, a 24"x48"x4" board of the 8pcf weighs over 20 pounds (plus the frame), so mounting to the ceiling may become an issue.
 
I have a suspended ceiling, I have no frame to build since I just have to remove a part of the ceiling, place the mineral wool, and replace the part of the ceiling, altough I don't think my ceiling will be able to old 160 pounds... I've seen the safe'n sound roxul. Do you know what's the weight for a 24"x48"x3" pannel?
 
wannabecomedeat said:
I have a suspended ceiling, I have no frame to build since I just have to remove a part of the ceiling, place the mineral wool, and replace the part of the ceiling, altough I don't think my ceiling will be able to old 160 pounds... I've seen the safe'n sound roxul. Do you know what's the weight for a 24"x48"x3" pannel?
Click to expand...

looks like the "Safe" is 4.5 pcf, which would work out to about 12 pounds per panel of the 4 inch.
 
A ceiling is a wall.

We give these things different terms based on our orientation but to sound it is just a surface in a box. So your two concerns are first order reflections from the speakers and slap echoes between the walls and the floor.

For the first you will usually be placing a 'cloud'...essentially a suspended midrange trap above and just ahead of the listening postion.

For the second you need to look at what is on the floor. If it is a hard surface then you will want something absorbant on the ceiling such as an additional cloud or possibly diffusing instead. if the floor is already absorbant then you most likely do not need anything all that special on the ceiling
 
Safe n Sound seems to be 2.5 pcf(fluffy), SAFE is 4.5 pcf

http://www.bobgolds.com/AbsorptionCoefficients.htm

I t seems commonly that diffusion(1d style) with less than 11' to the source would just
skew things, but someone (with seemingly acoustical stature)said it does'nt matter-though it seemed to be from someone that sells these new diffusors. I need to search for that thread.

T
 
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