C
catcando
New member
I will preface this request with the information that I am not building a studio, but a listening room.
Many of the same principals apply, hence my post here.
About 12 years ago, I paid an acoustic consulting company to design an external room for me. I had an existing barn, which was about 18' by 27', with an open raftered roof. The completely free standing room I now have , is about 16' by 25' by 8'. The only thing in common, is the solid slab concrete floor, which is covered with a dense felt underlay, and high quality dense carpet. The walls are built of very high density concrete blocks 8" thick, and then covered with an 1" of plaster. The ceiling is made of three different thicknesses of plaster board, all cross laid, covered with a layer of plaster. Above the ceiling is 12" of fibreglass, made up of, three different densities of 4" slabs.
If I can figure out how to introduce a drawing of the the shape of the room, I will, later.
The door to the internal room is made up of two 1" thick pieces of marine plywood, for the door facings, built on a 2" by 4" frame, and the hollows are filled with sanitised sand, so the door is about 3" 7/8" thick, and weighs over 200 pounds. This is mounted to an acoustically sealed door frame.
After reading Ethan Winer's writings on building acoustic resonant panels, and some information I found about the resonant frequencies of plywood, and the absorption characteristics of 703 and 705 rockwool, I have a few questions.
. Approximate full sheet [4' x 8'] plywood panel resonances when mounted on a 1x4 frame 3.5" deep are:
• 1/8" plywood = 150 Hz
• 1/4" plywood = 110 Hz
• 3/8" plywood = 87 Hz
I am guessing that 1/2" plywood would be about 55 Hz based on the above figures.
As the resonant panels that Ethan recommends are all built on half width plywood, the resonant frequency, is going to be even higher. If we are trying to control low frequencies most effectively, why are we not using full sheet panel sizes? Ethan uses 1/8" and 1/4" ply, on 2x8 frames, and not 4x8 frames.
As I am preparing to build some of these resonant panels in my room, I would like to verify what the best combination of panels sizes, panel thickness, and rockwool density to use are. I also have 8 RPG abfusors to use as well. My initial idea is to build 2 bass panels, full size, using a different thickness panel on each one, and 703 in one, and 705, in the other. The high bass panels, I would do the same, just using thinner panels.
Another question I have is whether it is useful to dampen the back of the resonant panels, so they do not "ring" as much, either with the bitumen based products that you can buy in sheets or rolls, or maybe something cheaper like liquid bitumen, and roofing paper.
I hope this is alright as an opening salvo, to my project.
Thanks in advance for any help.
Many of the same principals apply, hence my post here.
About 12 years ago, I paid an acoustic consulting company to design an external room for me. I had an existing barn, which was about 18' by 27', with an open raftered roof. The completely free standing room I now have , is about 16' by 25' by 8'. The only thing in common, is the solid slab concrete floor, which is covered with a dense felt underlay, and high quality dense carpet. The walls are built of very high density concrete blocks 8" thick, and then covered with an 1" of plaster. The ceiling is made of three different thicknesses of plaster board, all cross laid, covered with a layer of plaster. Above the ceiling is 12" of fibreglass, made up of, three different densities of 4" slabs.
If I can figure out how to introduce a drawing of the the shape of the room, I will, later.
The door to the internal room is made up of two 1" thick pieces of marine plywood, for the door facings, built on a 2" by 4" frame, and the hollows are filled with sanitised sand, so the door is about 3" 7/8" thick, and weighs over 200 pounds. This is mounted to an acoustically sealed door frame.
After reading Ethan Winer's writings on building acoustic resonant panels, and some information I found about the resonant frequencies of plywood, and the absorption characteristics of 703 and 705 rockwool, I have a few questions.
. Approximate full sheet [4' x 8'] plywood panel resonances when mounted on a 1x4 frame 3.5" deep are:
• 1/8" plywood = 150 Hz
• 1/4" plywood = 110 Hz
• 3/8" plywood = 87 Hz
I am guessing that 1/2" plywood would be about 55 Hz based on the above figures.
As the resonant panels that Ethan recommends are all built on half width plywood, the resonant frequency, is going to be even higher. If we are trying to control low frequencies most effectively, why are we not using full sheet panel sizes? Ethan uses 1/8" and 1/4" ply, on 2x8 frames, and not 4x8 frames.
As I am preparing to build some of these resonant panels in my room, I would like to verify what the best combination of panels sizes, panel thickness, and rockwool density to use are. I also have 8 RPG abfusors to use as well. My initial idea is to build 2 bass panels, full size, using a different thickness panel on each one, and 703 in one, and 705, in the other. The high bass panels, I would do the same, just using thinner panels.
Another question I have is whether it is useful to dampen the back of the resonant panels, so they do not "ring" as much, either with the bitumen based products that you can buy in sheets or rolls, or maybe something cheaper like liquid bitumen, and roofing paper.
I hope this is alright as an opening salvo, to my project.
Thanks in advance for any help.
