John Sayers' Recording Studio Design Forum Archive

I'll be ordering studio glass between the control room and live room soon.
Three windows, two panes each totaling six panes.
I'm looking at two 1/4" panes with lamenate between. Each pane is then a robust 1/2" thick.
Anything I need to be aware of before I spend $2g's on this? Are there cheaper options that might provide the same isolation? Thanks in advance.

I am not an expert but I would instinctively go for two different thicknesses in each pane sandwich.

DanDan wrote:I am not an expert but I would instinctively go for two different thicknesses in each pane sandwich.

Interesting idea. Meaning both panes are still the same overall thickness?

Couple of shots of the windows I'm referring to.

Yes, same overall thickness or greater if you can afford it. It will probably be down to what is available. I think more trumps when you have a sandwich with a damping layer. But different thicknesses will have different weak spots, bending resonance. So no double bubble.

DanDan wrote:Yes, same overall thickness or greater if you can afford it. It will probably be down to what is available. I think more trumps when you have a sandwich with a damping layer. But different thicknesses will have different weak spots, bending resonance. So no double bubble.

I'm looking at double 1/2" panes per window now. Not thick enough?
Not sure if I can afford thicker...correction, I'm sure I can't afford thicker.

do you mean 2x 1/2" per pane (i.e. 2 1" panes), or 2 1/2" panes per window? if the latter is as much as your budget can handle, then go with that. you could later add a laminated layer when your budget allows.

gullfo wrote:do you mean 2x 1/2" per pane (i.e. 2 1" panes), or 2 1/2" panes per window? if the latter is as much as your budget can handle, then go with that. you could later add a laminated layer when your budget allows.

Yes sorry I wasn't clear. Each pane will be two 1/4" glass with laminate between totaling 1/2" thick.
Each window get two panes. Three windows...six half inch panes total.
Didn't know I could add another laminated layer to an existing window later.
Sounds like a pain. (pun intended)
So if two 1/2" panes per window will give me the desired separation I'll go with that.
Still wondering if there are any less expensive alternatives to glass?

since your windows will have glass installed after the frame is installed (so you can properly clean it etc before sealing it) you could removed the glass and add a pane. yes, it will be more difficult than doing it now (perhaps you can do 3x 1/4" on one of the panes) but its doable.

the glass is good because its dense. matching the wall densities becomes much easier and lower cost than light window materials which ould require much thicker (re: $$$) to achieve. possibly less costly and more isolating - seal up the walls and use video camera and monitors to "simulate" the windows. a proper hardware controller will keep things real time and high resolution. in addition, you can have monitors on your tall gobos so your "windows" can extend around the live room...

gullfo wrote: - seal up the walls and use video camera and monitors to "simulate" the windows. a proper hardware controller will keep things real time and high resolution. in addition, you can have monitors on your tall gobos so your "windows" can extend around the live room...

Thanks for the info Glen. Much appreciated.
As far as sealing up the walls (control room windows) in favor of video cameras...maybe an option in the future. If the glass provides the isolation that I hope, it will tie the two rooms together visually and create a nice open feel to the studio as a whole. Something we were after from the initial design.

Take a look at this document from STC Viracon. It lists specs for laminated pane thickness and air gap size etc.
This document does not take into account the window frames however.

Also, yes, two laminated panes of different thickness will help reduce the coincidence effect. Match or exceed the surface densities of your wall assemblies and don't forget to add desiccant in the cavities.

The coincident effect is not really an issue with thick (e.g. 12mm) laminated glass. In INSUL simulations 2 panes of the same thickness seems to always be better than different thicknesses, this is due to the damping layer between the individual glass panes. If you go for different thicknesses then you will have less mass than you could have done with two panes of the same thickness. More mass (damped) is better

Hi Paul. Could you clarify please? Surely two different thicknesses with a damping layer is better than two equal thicknesses with a damping layer when the overall thickness is greater?

Elusive Sounds wrote: and don't forget to add desiccant in the cavities.

Thanks for that attachment ES. If I'm to add desiccant between the two panes how would you recommend I do that? Thanks

as a general note, assuming a decoupled wall set, you would also have the windows installed on each wall and also separated so as not to bridge the walls. the small air gap between window jambs can be sealed with caulk or simply masked with cloth. after one window is installed, add the desiccant unit(s) then install the other window. remember to clean the insides of each window before installing it