I read through the master thread and got more confused as I read. I have a room that is 12x12X8. I covered the front wall with 1' x 1' x 2' (the 2 is thickness) Auralex SonoFlat Panels except where the screen is. I have an ez elite screen which I belive is reflective?????? I did the refelection points on the side walls with 2x2x2 SonoFlat Panels. My sub is placed on an Auralex Subdude. For the rear wall should I use the Sonoflat Panels that I used everywhere else directly across from the screen only or should I use the panels on the whole rear wall. Or should I be using difusion and absorbstion across from the screen. Or all Difusion or nothing at all. I really want to finish my theater so any help would be great. One more question, should base trapps be used in all corners or jsut in the front or rear. Thanks in advance.

Here is my thread on the topic.

http://www.avsforum.com/avs-vb/showthread.php?t=1071797&highlight=back

I was not allowed to build the wall. I ended up moving my subs, placing some bookshelves and decorations in the back for diffusion. I'm also having to beef up absorption everywhere else. I have to equalize the rest.

I am not an expert on the subject but have done a lot of investigating for my room which is 13 x 17 x 8. From what I have read I determined that my room is too small for diffusion to be effective. I was considering diffusion on my rear wall but read in several different articles that 2 to 3 meters distance is needed from the diffusion to the seating area in order for the diffusion to be effective. I can’t recall the specific articles just to a search on diffusion.

I used absorption at the reflection points, on the rear wall, and bass traps in the corners. I covered approximately 35 % of my room with absorption. The percentage is calculated using the square footage of the walls and ceiling. Do not include the floor – again determined from my investigating and can be found on the web. Some manufactures websites can also be very useful.

I made my own acoustic panels. A description can be found at:

http://www.avsforum.com/avs-vb/showthread.php?t=1089543

Mike

Is 35% the standard amount of absorbtion in a room? Right now I am at 18% with the rear wall, sides and front using your calculation of all the walls and the ceiling. Thanks

Is 35% the standard amount of absorbtion in a room? Right now I am at 18% with the rear wall, sides and front using your calculation of all the walls and the ceiling. ThanksYour going to need to measure the room to find out, but try using this. Enter your room size and scroll down to the area that reads similar to this. http://www.bobgolds.com/Mode/RoomModes.htm

Absorbtion to achieve ITU RT60: 523 sabins
Volume: 2322 ft^3
Surface Area Total: 1116 ft^2
Surface Area Floor: 270 ft^2
Surface Area Ceiling+Floor: 540 ft^2
Surface Area Front Wall: 116 ft^2
Surface Area Front and Rear Wall: 232 ft^2
Surface Area Left Wall: 172 ft^2
Surface Area Left and Right Wall: 344 ft^2
Surface Area 4 Walls: 576 ft^2
Surface Area 4 Walls + floor: 846 ft^2
(sabins - front wall - carpet) / Left+Right+Rear wall: 29 %
(sabins - front wall) / Left+Right+Rear wall: 88 %
Schroeder Fc: 108hz
Frequency Regions:
- No modal boost: 1hz to 28hz
- Room Modes dominate: 28hz to 108hz
- Diffraction and Diffusion dominate: 108hz to 432hz
- Specular reflections and ray accoustics prevail: 432hz to 20000hz
Count (28.2-193hz) : Axials=12, Tangentials=44, Obliques=48
Count (28.2-100hz) : Axials=6, Tangentials=7, Obliques=2
Critical Distance (direct = reverberant field): 14.50ft

So if I'm reading that data right, you would need to treat 29% of the left/right/rear wall surface area, assuming that you fully treated the front wall and have carpet?? It's a bit confusing.

So if I'm reading that data right, you would need to treat 29% of the left/right/rear wall surface area, assuming that you fully treated the front wall and have carpet?? It's a bit confusing.

It looks like to me like it is using the floor with carpet as a standard caculation. This way if you wanted to factor the absroption for that you could be more careful as to not overtreat the room. This would be taking more than one approach which will vary from designer to designer. That is just what I see. Sorry I can't find the instructions.

So if I'm reading that data right, you would need to treat 29% of the left/right/rear wall surface area, assuming that you fully treated the front wall and have carpet?? It's a bit confusing.

I used this one to caclulate sabines. It's a little more complex, but you can enter your own here.

http://www.marktaw.com/recording/Acoustics/RoomReverbSabineCalculato.html

Check out this link for room coverage.

http://www.truesoundcontrol.com/products/roomkits.html

Mike