Corner superchunks with air gap?

[Glenn Kuras]

It should help a bit, but please test. Looking forward to seeing them.

[avare]

Originally Posted by tomeford

I've made 4 superchunks for my mix room. Triangle bits stacked up in the corners. They are in frames which make them completely portable and can stand up with no wall support. (this was done so I didn't have to damage the walls)

This gives me the possibility of moving it away from the walls a bit to create a bit of an air gap behind the triangles. I'm planning on doing some before and after tests when I have a chance but I wonder if anyone has thoughts or experience with the idea...?

Why? Superchunks are 17" deep. This gives great absorption down to ~31 Hz. Do you need lower absorption?

Andre

[tomeford]

I wasn't thinking of lowering the frequency so much as helping absorb a little more.

Will do some tests to see what difference it makes. I've got some pretty serious issues under 200hz still, after covering all walls and 6 corners. (4 wall corners and 2 front ceiling and floor)

I'm actually second guessing the insulation I used for the corners, but that's another topic...

[jwl]

Are these the 17" chunks, or the 24" chunks?

Depending on the answer to that, I'd except maybe a bit of improvement but not earthshattering. That said, I look forward to the results of your testing.

[sheggs]

Originally Posted by tomeford

I wasn't thinking of lowering the frequency so much as helping absorb a little more.

Will do some tests to see what difference it makes. I've got some pretty serious issues under 200hz still, after covering all walls and 6 corners. (4 wall corners and 2 front ceiling and floor)

I'm actually second guessing the insulation I used for the corners, but that's another topic...

You say its under 200hz, have you been able to identify exactly at what hertz you are experiencing these issues?

[tomeford]

Ok, here is my file from room EQ for before and after treatment.
I've not done the air gap test yet...

Obviously 143 is a problem. But i'm also concerned about what happens overall below 200hz on the waterfall. Doesn't look like my traps have been broad enough.

Some context. Room is 4.8m X 2.75m. Speakers facing long wall.
It's surrounded by double brick, which obviously makes things tricky.

I have 6 1200mm X 1600mm X 75mm acoustisorb 3 (48kg/m3) panels covering almost all the wall surfaces. They have a 75mm air gap behind them.
I have a 1200mm X 2400mm cloud made from acoustisorb 3. That has a little more air above it.. not sure how much.

I have 4 ~17" chunks made from fluffier stuff. I can't remember the kg/m3 but i have these specs here on my computer..

5000mks Rayls/m. and...
125 250 500 1000 2000 4000 5000 NRC
0.60 0.98 1.03 1.05 1.14 1.10 1.09 1.05

I've then got the offcuts of acoustisorb 3, 2 pieces of 1200mm X800mm resting in floor/wall and wall/ceiling corners at the speaker end of the room.

So straying from the chunk air gap question... what do you think? Hope this makes sense.. be kind. i'm doing my best.

[tomeford]

any thoughts?

[fsharpau]

"I have 4 ~17" chunks made from fluffier stuff. I can't remember the kg/m3 but i have these specs here on my computer.."

How tall are your chunks and which corners are they in? Also how high is your room? (I may have missed that)

I'm fairly new to acoustic testing - working on my small room at the moment (also in Sydney and using Acoustisorb 3)
Were your test mic and speaker positions exactly the same for each measurement? I'm no expert but have noticed the big differences that small movements in mic position can have on IR.

David

[tomeford]

Chunks are 2200mm high. Ceiling is 2300mm on the left speaker side and 2400mm on the right. Cloud sits about 2200mm high.

Unfortunately I wasn't able to ensure exact same position for both tests. (new carpet was put in between which lost my markings - I didn't know that was going to happen...)

First test I was looking for the best spot in the room to find the ideal mix position. Treatment was designed with that position in mind. Second test is in the final mix position. Which may be give or take 10cm in any direction from the first test.