Need help with studio design

[Darm]

I've been reading this forum for a long time. Now I am finally about to
have a studio outside my bedroom, so I need a little help with the
acoustical design.
What I will have is an almost square room 4.05*4.2 meters, with a tiny
1.3 *2.54 meter room connected with it. The room height is 2.65 meters
I am planning to use the big room for mixing and production, and the tiny room for recording some sketch vocals.
So far my plans are putting a glass door at the tiny room entrance,
putting an armstrong ceiling. I don't know what would be the best
option for eliminating reflections in the vocal booth- would it be ok,
if I just put a broadband absorbers on all of the walls, or should I
cover the wall from the bottom to the top? would it be better if I cut
one of the corners with an absorber, making a room weird shaped?
And how should I place the traps in the control/production room?
Should I do the armstrong ceiling a little slanted?
Here's a little pic. The triangles are nearfield monitors tat I am planning to put on stands. I am also wondering if I should put them wide, or not?
I can't really rebuild this room, since I am renting it. All the walls are made of brick, and covered with cement and wallpaper on top.
http://farm3.static.flickr.com/2265/...9cebacd420.jpg

[Ethan Winer]

In a square room like that you need as much bass trapping as possible, and in the booth you need bass trapping and also a lot of mid-high frequency absorption to kill everything. Small room ambience is always bad ambience, so you'll just add whatever ambience and reverb you want later electronically.

As for all of your other questions, see my Acoustics FAQ:

Acoustic Treatment and Design for Recording Studios and Listening Rooms

This will also be useful for you:

RealTraps - How To Set Up a Room

--Ethan

[BudgetMC]

Mr. Winer speaks the truth. And he plays a mean cello.

[tINY]

This is the kind of room where 2 or 4 sub woofers can even out the bass a lot when placed properly. You'll still need traps in 8 of the 12 corners....



-tINY

[Darm]

Thanx a lot Ethan, I had already read your book, and well, then I will try to buy as much rockwool as I can, put it in the frames, and just place it everywhere!
Still is it ok at first to put bass traps in the booth a bit up from the floor? or is it that important to cover the whole height of the room?

[Ethan Winer]

Originally Posted by Darm

Still is it ok at first to put bass traps in the booth a bit up from the floor? or is it that important to cover the whole height of the room?

The more corner surface you treat with bass traps, the better. Always.

--Ethan

[Darm]

Got another question for you Ethan
If I am going to put these
http://www.ethanwiner.com/basstrap.gif
in the corners of the big room, and one cutting the corner of the booth, Do I cover the back with plywood, or do I just put the plywood on the front, and leave the back with fibergalss open, or maybe covered with fabric?

[Glenn Kuras]

Originally Posted by Darm

Got another question for you Ethan
If I am going to put these
http://www.ethanwiner.com/basstrap.gif
in the corners of the big room, and one cutting the corner of the booth, Do I cover the back with plywood, or do I just put the plywood on the front, and leave the back with fibergalss open, or maybe covered with fabric?

That is a tuned bass trap not a broad band bass trap. Those you would not straddle corners and I would not recommend those in a small vocal booth. For that you are much better to stick with a broad band bass trap that will absorb more of the over a frequencies instead of a target area.

Glenn

[Ethan Winer]

Darm,

I'm with Glenn. In a room like yours you want broadband bass traps, not tuned panels. If you look at my bass traps article again, you'll see this note in bold text at the very top:

Please understand that the bass traps described in this article are intended mainly for larger rooms. For rooms smaller than 25 by 15 feet you'll usually do better with broadband bass traps made from thick rigid fiberglass placed in the room corners. This is described in my Acoustics FAQ linked above. Once all of the corners are treated, then it makes sense to consider adding bass traps like these flat on the walls.

--Ethan

[Darm]

ok, sorry for not paying enough attention
is that the right way to treat a corner ?
http://www.ethanwiner.com/corner-trap.gif
And yeah, I should place the traps on the side walls halfway between me and speakers, cause theat would be the first reflection point, right?

[andrebrito]

Bass traps on corners. Absorption on first point reflections.

I prefer to place absorption on the front wall.

As important is 1) size of speaker and 2) listening position and location of speakers.
Best way to check this: measurements !
(altough there are software for prediction (some more complicated to use then others) it is always better to make measurements).

You can use two cheap mics for this: Behringer ECM 8000 or Beyer MM1. Search on the internet for Room EQ Wizard, it is a free software that you can use to make measurements, it is easy to use.

[Darm]

Yeah, I forgot to ask that- why do I need placing broadband traps behind the speakers? I've seen it a lot, and never understood why

[Glenn Kuras]

Originally Posted by Darm

Yeah, I forgot to ask that- why do I need placing broadband traps behind the speakers? I've seen it a lot, and never understood why

It will help with SBIR (Learn what is SBIR (Speaker Boundary Interface Response).).

Glenn

[andrebrito]

If you have your speakers mounted in the wall then the front wall can be an hard surface but I think this is not your case. You should place also a corner trap in the front wall because of tangencial modes and as Glenn told about SBIR effect

[Darm]

Yeah, I wan to put the monitors on a stands made out of steel tubing and filled up with sand. I am also going to put some rubber on top of them.
This way I be able to put a table off the wall, and put monitors 10-20cm off the wall too

[Darm]

Originally Posted by andrebrito

Bass traps on corners. Absorption on first point reflections.

I prefer to place absorption on the front wall.

As important is 1) size of speaker and 2) listening position and location of speakers.
Best way to check this: measurements !
(altough there are software for prediction (some more complicated to use then others) it is always better to make measurements).

You can use two cheap mics for this: Behringer ECM 8000 or Beyer MM1. Search on the internet for Room EQ Wizard, it is a free software that you can use to make measurements, it is easy to use.

What kind of preamp shold I use if I consider getting ECM 8000?

[Darm]

So I bouth the mineral wool makred as p75 mineral basalt wool.
Now I would like to find out what's the best way to mount it on the wall?
And how do you mount it in the corners?

[andrebrito]

Any clean mic pre will do.

What is the density of the mineral wool ?!

[joelpatterson]

Good God, this stuff really hurts my head....

[Darm]

Its 50-70kg/m3.. seems like its okay.
I amde a few traps, and I wonder if that cheap thin material I am covering it with will hold it good enough. I don't want people to be breathing basalt...