My first rehearsal room is next to finish...(new pics)

[hugo_inside]

Hi everybody,

As some of you knows, I'm building some rehearsal rooms and a recording studio.

Well, my situation was the next:

1.- We had 5 meter x 3 meter x 2,75 m height room where 3 walls were concrete block sand filled and the rendered with gypsium and then painted.

2.- My idea was floating the floors, the door were at 0,15 m heigh but EPDM rubber or Neoprene was very very expensive. And I build a floating floor with 6 mm panels of very high density made for floating floors instead of EPDM. Between the joist I put half room with 80 mm fiberglas low density and the next half with dry sand. Then I cover the joist with PVC sheet and 2 plies of fiberboard and 1,5 mm of linoleum.

3.- the front wall were the existing wall, and I try to absorb some reverb covering all the wall with rockwool 40 kg/m3 panels 40 mm thick. then I cover it with mosquito mesh...

4.- the ceiling is made of gypsium panels 15 mm and 80 mm fiberglass low density over them.

Well, I think the room doesn't sound well at all...

What can I do? ( I try to post some pics soon )

[hugo_inside]

I must say, the test I try it's only with empty room and bass drum and snare.

[John Sayers]

For someone who has made over 200 posts at this site I would have thought you would know why it sounds shithouse.

cheers
john

[hugo_inside]

Ok John ,

I know the walls are parallel and hard. Steve tell me about fill all the ceiling/wall corners and at least two wall/wall corners. But I have 2 problems here not solved:

1.- I have no space for corner traps. No space for 3' (90cm) wide corner traps, maybe only for one... One 3' corner trap is better than two 2' corner traps?

2.- the second problem is , how to attach panel to ceiling/wall corner?? Any idea?

Sorry if I so tedious... My building is very delayed and I don't wanna goof no more...

[knightfly]

Exactly what is behind your gypsum wall panels, and also what material is your ceiling joists made of? If I remember correctly, there was some pretty unusual construction in some of your pix... Steve

[hugo_inside]

Is not gypsium panels, it's 200 mm hollow concrete block sand filled and then rendered with gypsium.

Ceiling joist are concrete with steel bars inside.

Three pics of blocks, ceiling joists and rendering...

[drfrankencopter]

So, what's the problem? Flutter echo? Or a mode problem? Is the floor resonating?

In what way does it sound bad???

Cheers,

Kris

[hugo_inside]

two kind of sound problems:

1.- There are a lot of reverb No long reverb but I think so bad for practicing...

2.- I don't know how to explain the second problem. When I clap my hands it sound like very short delay, ringing sound, maybe paralell walls cause this sound. This is flutter?? I know the terms but no the sound

Any help?

[hugo_inside]

If you clap your hands in a room and hear an echo that is a spring type of sound (BBOOOIIINNNGGGG!!!!), that's flutter echo. It is unlikely that you would be happy with any of your samples that are littered with this. Flutter occurs in rooms with hard parallel surfaces, especially when they're close together. An easy fix is hanging blankets on the walls to absorb the high frequencies bouncing around that make the echo. Placing soft furniture in the room will also help.

yes, my second problem is this... [/i] But I think blankets is not a good way...

[drfrankencopter]

Good news....flutter echo is pretty easy to treat. You have three issues really:

• 1. Since your room is small it has a poorly developed reverb tail. By this I mean that there are few discrete reflections in the reverb. Think of this as like the 'density' control on a digital reverb.
  2. The hard walls mean that the few discrete echoes that you have will persist for a long time (i.e. longer RT60). This is like the reverb time control on a digital reverb.
  3. The parallel walls force the echoes to interact and cause comb filtering (the BOING sound). This would be like taking a digital reverb and turning the diffusion control to near zero.

The good news is that flutter is a high frequency problem. The solution is diffusion or absorbtion, or a combination of both. If your reverb time is too long, use absorbtion (remember that thicker treatments are better), and if you want to preserve the reverb time, use diffusion.

Try messing around with a digital reverb to simulate the effects of using diffusion or absorbtion to address the problem.

I would advise you to treat the ceiling with absorbtion. Use 703 or a local substitute across the ceiling. 1" panels spaced 1" from the ceiling should go a long way towards taming the problem. Then use spot treatments on the walls (combinations of diffusers and absorbers) to break up the flutter echo.

Remember that any edge in your wall produces diffusion, it doesn't have to be fancy special purpose (read expensive) diffusers. Put up some wall mounted book or CD shelves. Even the edges of wall mounted absorbers act as diffusers. From there you can do spot placement of 703 to tame any remaining flutter echo.

Hope this helps.

Kris

[hugo_inside]

thanks Kris,

I don't listen the room with all the band inside. Perhaps guitar and bass amps, hardcases, people, etc, acts as absorbers and difusors ... doesn't it?

the problem of hanging 703 panels is the toxicity of rockwool...

[AVare]

the problem of hanging 703 panels is the toxicity of rockwool...

??? Read:

http://www.recording.org/ftopict-21013.html

Healthy;
Andre

[hugo_inside]

Perhaps is not toxic like fiberglass but in my own experience touching rockwool panels and fiting in place, cause me irritation in my skin and my throat.

In the other hand I'm thinking of using 1" rockwool ceiling panels in the ceiling/wall corners



what about this idea?

[drfrankencopter]

I don't think that amps, cases, and people will make a big difference....well not as big a difference as some well placed absorbtion and diffusion will.

People, and amps/cases will diffuse the lower half of your room, so concentrate your efforts on the upper half. From midway up the walls and up, including the ceiling. Here is where cases, amps, and people have no effect (and it's right where our ears sit).

Regarding 703, it IS a fiberglass, just a rigid one. It is not a proven carcinogen, but it is pretty nasty to work with. Wear gloves, and a mask, and preferebly do any cutting outside. Cover your panels with fabric, and itf that isn't enough to keep the fibers in, put a thin layer of polyester batting between the 703 and the fabric outer covering. This will keep the fibers in.

Cheers,

K

[hugo_inside]

Thanks for your answer Kris

As you can see in the pic, the walls and ceiling are painted, and I want to keep the ceiling or big part of it with this paint...

I know cover all the ceiling with another removable ceiling will work, but it so much money and time and I don't have money and time...

Does my idea of hanging a removable ceiling on wall ceiling corners works?? what do you think?