how to build studio windows....?

Posted: Sat Feb 28, 2004 9:11 am

Hi.

Iam building a studio. Ca. 250m².
ground plan here: http://www.nrgrecording.de/assets/images/2.jpg
come pictures here: http://www.nrgrecording.de/html/pics1.html

And now i'm thinking about...
how to build the windows between recording room and control room.

Yesterday i got 10 glass panels. 10-12mm thickness.
:confused:
picture a,b or c ?

Are there some links about building a studiowindow? Are there problems with condensation water between the glasses?
The glasses are a bit heavy. How to mount them?

<img src="http://www.nrgrecording.de/assets/images/fenster.jpg" alt=" - " />

Kind regards,
Frank.
http://www.nrgrecording.de/diy.html

Posted: Sat Feb 28, 2004 9:21 am

I believe the rule of thumb is that C gives the largest isolation (sound transmission loss) because it has the largest airspace between the panes of glass.
On the other hand, you might choose A or B if you want to RFZ reflections off the glass somewhere other than the same direction as the wall.

http://www.saecollege.de/reference_material/pages/Windows.htm
http://www.customaudiodesigns.co.uk/articles/windows.htm

from studiotips

Quote:

Windows. For Windows, again DO NOT use triple leafed systems. Also, apply the concepts of air tightness, mass, mechanical decoupling, cavity absorption, and differentiation of materials. A simple but effective design for a window is to build a deep frame in the wall (in excess of 4”s) and line the interior with cloth covered 703, do not make the two sides of the wall more mechanically connected than they already are, then install two panes of heavy glass in different thicknesses resting on neoprene bumpers as far apart as the frame will allow (at least 3.5”s), finally caulk around the gap at the edge of the panes with butyl rubber to make the window air tight on both sides. Laminated is an excellent choice for this sort of system. Some folks slant one pane of glass - but others think this is a bad idea and recommend that maximum air gap be maintained, follow up by defeating flutter echo off the glass by treating the opposite wall with absorption or diffusion.

Posted: Sat Feb 28, 2004 9:31 am

Thanks z60611.

I'd just seen another direction of the glass at galaxy studios:
Rolling Eyes

Has someone technical drawings or pictures about the windows constructions?

Regards,
Frank.

Posted: Sat Feb 28, 2004 12:06 pm

Sorry, I don't do windows. So the only links I have are the two I posted above.
(I mention this in case we posted at the same time)

Posted: Sat Feb 28, 2004 3:12 pm

Eric would know, he designed much of galaxy
galaxy
the man knows his physics.

Dan

Posted: Sat Feb 28, 2004 7:26 pm

Quote:

Eric would know, he designed much of galaxy
galaxy
the man knows his physics.

Dan

Regards,
Frank.

Posted: Sun Feb 29, 2004 3:05 am

Frank,

He you scare me. Wink

Don't dare to ask , have we met somewhere?

I'm a member in the background.
My home is
http://forum.studiotips.com

Anyhow thanks:
I've never got such an enthousiastic response on the net.

Kind regards
Eric

Posted: Sun Feb 29, 2004 5:43 am

Frank,

Just short,

Dan gave a correct answer.
In function of isolation a lot of study work is being done related to angled glass.

Whilr there is still some doubt, in fact tests prove that the angling in itself has little or no impact on the isolation.
But edge absorption does.
It works as any double leaf system with this disadvantage that the cavity isn't damped as with a standard drywall.
This edge absorption partly compensates for that, certainly with large cavities.

So the comment of Dan and others that the volume of the aircavity is meanly defining is correct (mass-spring-mass system).

However with very large cavities altering the volume will have less and less impact.
In that case one can angle the glass a bit. This has only effect on the traveling waves above the first cavity resonance (in fact starts somewhat lower in freq).
This angling of the glass also direct the traveling waves towards one direction (the widest) were you can concentrate thicker absorption to get lower in frequency.

Further the angling should be seen in function of the sound propagation/distribution in the room (reflections, boundary interference, etc.)

Note that one only can direct traveling waves, not standing waves (modal frequencies). And cavity resonances are modal frequencies.

The high insulation of the windows you refer to is related to the fact that this is an interactive studio.
One can record a wispering sound together with a rock ensemble in another studio, and a symphonic orchestra in the big hall.
All those studios and control rooms can be combined in a lot of different configurations, have a common shared machine room with the main computers, recorders and whatever (don't understand a thing about that) and can work simultaniously.

Best regards
Eric

Posted: Tue Mar 02, 2004 2:10 pm

Thanks Eric Desart and z60611!

Whats the best decicion of making the walls for the windows?

Around the studio i would like to use drywall. Thats the backside of the studio and not directly next to the recording room.

But the wall where i will attach the windows is next to the recording room.

I thought about 3 sheets of drywall. I want to plug up every single sheet of the sheetrock. (better isolation?)

OR

iam thinking about to bring up the walls with lime malm brick. i read that it could be a good idea to fill the gap with sand... !?
Then there is a good isolation, but low frequencies could reflect more..!?
So i need more bass-absorber?

Which idea is better? :
Wink

:confused:

:c:

Kind regards,
Frank.

Posted: Tue Mar 02, 2004 2:34 pm

Frank,

1) Do not forget the edge absorption I described.

2) Try to get a somewhat lower mass-spring resonance for the windows than for the drywall (to compensate for the lacking wool or glassfiber).
On my site you find a file to calculate that.

3) Use the same principle for wall as for windows.
The sand filled wall becomes a damped single leaf with a deviating acoustic behavior. You overal isolation is dominated by the weak points of the 2 different systems (corrected in function of surface contribution). Your window is a double leaf system. So use the drywall system.

4) you don't speak about wall thickness (cavity?)
Better is more to full cavity filling with wool.

5) You can shortcut the edge of the window cavity with the cavity in the walls to get edge absorption (finish with fabric or whatever, not transmitting structural sound)

6) Try to keep your window panes as much as possible flush with the outside of the drywall, to use maximum cavity width.

7) Are those panes laminated glass?

Regards
Eric

Posted: Tue Mar 02, 2004 4:18 pm

Additional:

Cool

Certainly if a pane is not laminated (monolitic glass) but also (less important) the edge damping is important.
Any panel knows internal modes exactly similar as rooms do. Only they are limitted to a 2 dimensional plane.
This means that the manner how such panes are mounted can significantly influence the transmission loss.

Siliconen has little internal damping. While it can caulk a window pane perfectly it will do relative little to increase internal loss in the widow pane itself.

Butyl is much better.
I don't know if you recognize following description:
Old plumbers mastik (used in the past in WC's etc.) if not drying (which it standard shouldn't) is a good material to put the window in.
Probably Rod can explain better.

In fact it's this kind of material used in Labs to assure perfect thightness and edge damping while testing window panes (they often use pumps).

Here there are companies selling this material in rolls were those stripes are preformed in rectangular or round stripes.
Sorry if unclear: I don't know exactly how to describe it.

Eric

<small>[ March 03, 2004, 01:59 AM: Message edited by: Eric Desart ]</small>

Posted: Tue Mar 02, 2004 5:04 pm

All that metric talk screws me up.
My window will be, well, lets start with walls. I'll have two framed walls with about a 6 inch gap in between them, not touching in any way, with a 2x4 foot piece of insulated 1 inch glass in each wall, directly across from each other. The edges will be seal tight of course. Hopefully this will do the trick just fine. Mostly I want to keep drum volume out of the CR, so I am building a "riser" which is nothing more really that a large thick rubber mat with 2 sheets of plywood on top.
Are 2 pieces of 1 inch glass, 6 inches apart or more, going to be pretty decent?
Paul

Posted: Tue Mar 02, 2004 5:18 pm

Quote:

Originally posted by tubedude:
with a 2x4 foot piece of insulated 1 inch glass in each wall, directly across from each other. Are 2 pieces of 1 inch glass, 6 inches apart or more, going to be pretty decent?
Paul

Paul,

You don't have 2 pieces of 1" glass - you have 4 pieces of (probably) 1/8" glass........ and this is going to make a VERY poor isolator.

1st off - the panes of glass each have very little mass - nothing compared to your walls -

2nd - the panes are all the same thickness - so you are going to have problems with sympathetic resonance

3rd - the installation of a 4 leaf system is not going to give you the same isolation that you would acheive with a 2 leaf system. WHat I mean by this is that 2 pieces of 1/8" glass with a 3/4" air space between (at each wall face) will not give you even the same isolation that 2 pieces of 1/4" glass would with the same air space between the 2 faces.

Not only is this not going to give you isolation you need - it's going to fail by quite a lot.

Rod

Posted: Tue Mar 02, 2004 8:45 pm

I dont understand, exactly.
The glass is 1 inch thick, very heavy, no frame, just a big piece of glass. Maybe I need to take another route then, but I still dont understand what you mean by my glass is not 1 inch thick. I can measure one inch at the edge.

Posted: Tue Mar 02, 2004 9:29 pm

Paul, you referred to your glass as "1 inch insulated" - to Rod and myself, that would mean two layers of glass separated by a wide air space in a common frame. That's the typical definition of "insulated" glass -

So you're saying your windows are SOLID glass 1" thick? Steve

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