Small mix room of death. HELP!!!

[College_Records]

Here are the dimensions of the space I have to work with. I must add that the ceiling is unfinished 10" deep beams running bottom to top on the diagram I drew below. The cavities in between the beams are filled with 10" of paper faced R30.




My original plan was to make a sort of mix trapezoid with slanted side walls and coat the inside of it out with 703 and rock wool (I have a lot at my disposal). I want the room to be as dead as possible. I have wayyyy too small of a space to shoot down the long length of the room, install diffusers, etc. The room is hopefully going to be big enough for 2 people and as dead and flat as possible.

I have a referance mic and REW and I will most likely be posting pics and results of tests.

By the way, I'm mainly mixing for computer speakers so a smooth, flat top end and mids is a must before any concernes with the sub 100hz frequencies.

Thanks so much Jens, Glenn, Andre, DanDan, John, and Rod. Your contributions to this forum have already helped me a ton!

- Sincerely, Andrew Winkler

[jwl]

Should be workable with the standard treatment strategies.... bass traps in as many corners as possible, absorption at first reflection points on the side walls and ceiling, and a good rear wall strategy.

RealTraps - Acoustic Basics

When testing, I'd be curious to see what effect the ledge has on your low end, you might focus some of your tests there to gather more info.

[College_Records]

Originally Posted by jwl

Should be workable with the standard treatment strategies.... bass traps in as many corners as possible, absorption at first reflection points on the side walls and ceiling, and a good rear wall strategy.

RealTraps - Acoustic Basics

When testing, I'd be curious to see what effect the ledge has on your low end, you might focus some of your tests there to gather more info.

Should room modes be a problem??

[Ethan Winer]

Originally Posted by College_Records

Should room modes be a problem??

Room modes are always a problem. That's why bass traps are needed.

--Ethan

The Acoustic Treatment Experts

[DanDan]

Modes are usually one of the problems. However you have sheetrock walls which may weaken the modes a bit. Also that 10 inches of trapping overhead should 'relieve pressure' for all the modes to some extent.
I would start testing. Use the results to decide which way to fire your speakers. Then do your side reflection points fully and carefully.
The Waterfalls will tell a lot about modes and may even distinguish BIR.
DD

[Glenn Kuras]

Originally Posted by Ethan Winer

Room modes are always a problem. That's why bass traps are needed.

--Ethan

The Acoustic Treatment Experts

+1

[Snatchman]

Hello..I've wondered about this since I've seen them made in different materials..What is the performance difference between wood and lighter materials in diffusors ( if any)..?..Is it just the variable hieghts/wells that matter or do weight mean anything..? What about cardboard diffusors..? Thanks..!

[College_Records]

Originally Posted by Snatchman

Hello..I've wondered about this since I've seen them made in different materials..What is the performance difference between wood and lighter materials in diffusors ( if any)..?..Is it just the variable hieghts/wells that matter or do weight mean anything..? What about cardboard diffusors..? Thanks..!

A diffuser's density, depth, and shape determines it's response to certain frequencies. For example, people new to acoustics are commonly mislead that cardboard egg crates or egg crate foam will diffuse sound. This might help a bit with the highs, but it leaves nasty low and mid reflections to deal with. Base frequencies take a much larger space and thicker, denser material to have any affect at all.

Space and diffusion
Lower frequencies take a longer distance to develope; that being said, once you get under 100hz, the sound waves can be anywhere from 5ft to 32ft to even longer. Generally speaking you need to affect 1/4 of the wavelength to make a difference. And 1/4 of 32 ft ( the approximate length of 35 hz) is 8ft... 8 ft deep traps to diffuse 35hz!!! My room's 10x10 and I don't have the room!!!

Density and diffusion
Do you really think 2" of cardboard will reject the same amount of lower frequencies as 2" of wood or 2" of metal. The denser materials reflect more sound. The goal of diffusion is to evenly distribute the reflections in the room ~ to reflect lower fequencies at all you absolutely need density.

That being said you need both SPACE and DENSITY to adequately diffuse a room.

Note: A lot of diffusers require you to be a certain distance form the wall (especially the low end) to achieve diffusion ~ that being said, if you're in a small room like me with scarce space, diffusion won't really work. The're just not enough room and you'll have a lot more success applying absorption and absorbing the modes before standing waves can build up.

Good luck! It's an uphill battle - Andrew

[Jens Eklund]

Originally Posted by Snatchman

Hello..I've wondered about this since I've seen them made in different materials..What is the performance difference between wood and lighter materials in diffusors ( if any)..?..Is it just the variable hieghts/wells that matter or do weight mean anything..? What about cardboard diffusors..? Thanks..!

Diffusors: opinions about EPS polystyrene?

But as stated previously; your room is a bit too small for diffusers to work as intended but if you still have the urge to use it:

Does my room need diffuser?

ISD gap for my room help pls!

[moorethanart]

So, I have a v small room too.
I understand about the need for bass traps in corners and back wall etc. I can't seem to find from my reading, do the bass traps also absorp a little mid and high necessary, or do they only trap low frequencies?
From my reading I understand that some mid and high frequency absorption is also necessary.

[Stackx]

yes they also absorb some mids and highs.. i don't know how much although there are some very very smart people here that im sure do. I think it depends on the thickness as well to how much low end it will catch and how much higher end it wont catch. there are also things you can do from my understanding that will help you keep some of your higher end if wanted like plastic and frk <--- but don't hold me to that i could be totally wrong.

[DanDan]

do the bass traps also absorp a little mid and high

A simple fibre panel will absorb HF very well. Thicker ones have a lower cut off point getting into the MF area. An airgap lowers this cut off point.
Corner placement greatly enhances the LF absorption, in ways similar to the bass boost a loudspeaker will experience in a corner.
The HF and MF remain the same.
If you want to lessen the amount of HF absorption, without losing LF performance, a layer of HF reflective card or plastic or much better a nice looking grid of laths will do it.

DD

[Glenn Kuras]

Originally Posted by moorethanart

So, I have a v small room too.
I understand about the need for bass traps in corners and back wall etc. I can't seem to find from my reading, do the bass traps also absorp a little mid and high necessary, or do they only trap low frequencies?
From my reading I understand that some mid and high frequency absorption is also necessary.

Above Dan Dan is talking about broad band absorption, which if you have a smaller room that is what you would want to focus on. You could also use Tuned as more icing on the cake, which is bass trapping that only deals with a certain frequency range. The following is using both tune and broadband.
http://www.gearslutz.com/board/7597560-post146.html

[moorethanart]

Thanks all!