Caulk for Studio Glass

Should add. The mastic needs to be continuous. Ie. No gaps.

I'd leave it ventilated between the panes unless you can create a vacuum between the panes.

Think of a drum.. What happens when you plug the vent hole? The resonance of the drum increases greatly because when you hit the batter membrane the gas has no where to go but to push against the other membrane.

If it has a vent hole, then it can push out of the holes rather than against the other membrane.

In your case, the glass is large enough to vibrate with significance. Having a sealed void full of gas will allow that gas to transfer some of that vibration to the inner glass pane.

Venting the gap will lead to lower sympathetic resonance.

In other words, there is "insulation" which rejects heat, and there is "insulation" which rejects sound.  They are mutually exclusive, so one doesn't necessarily mean it can do the other.

If I remember correctly there was a huge thread over at Sayer's forum about windows and the consensus was that gas-filled windows make sound transferal worse and that vacuumed windows work best.

Maybe you mistake my explanation.  The glass on both sides is sealed to the framing, but the air in between is vented to a sound proof area around the gap.  There is no air leaking between the rooms.  You are just giving the space between the glass a buffer so that it does not act like a spring to the next glass pane.

Look up MSM resonance.  Mass-spring-mass.

It's the concept of the dual leaf window system.

The concept is that you have mass (the window), a spring (the air sealed in the middle) and more mass (the other window).

If you put a pressure spring between the windows which do not have enough mass to resist the frequency of vibration, then the spring (the air sealed between) will transfer that vibration to the next mass (the other glass).

Here's an illustration of the typical window, with the gap in the framing between the studs, which serves as the ventilation between the glass panes:

tonycamphd Yeah, the dehumidifier is crucial.  I find that sweaty drummers can raise the humidity level in a sealed room by a great amount!

I run mine a lot, and I have a larger intake vent for the AC unit so I can ventilate the room quickly as well which keeps it pretty dry for the most part..

But I've been in some home studio environments where an hour with a few sweaty musicians in the room, the walls are dripping..  And for some reason those studios have had issues with corroded connectors..

But between the glass, you still have the gap leading out to the inner walls, which should have lots of dry insulation.  If you have fogging, your space has much bigger issues with moisture that need to be sorted out.

Yes, that's the main reason, but it also works better that way.  I'll see if I can find the link to the testing I saw.

Thanks everyone for all of the insights. The glass here is angled, as in example "B" above, however the wide side is to the top. The wall the window is installed in is at least two feet thick, so I would expect there must be some type of empty space dividing the front and back. And there is some sort of acoustic foam blanket lining the four surfaces on the inside of the glass partition, albeit some sort of old school pad, circa late seventies when the place was built.
I have mitigated all of the moisture problems within the house ( I hope ), through various means, and moisture within the studio area is no longer a problem. The forced hot-air furnace tends to dry out the air in the entire structure ( sometimes too much, I think ) and relative humidity within the entire home/studio has hovered in the forty-percent area, sometimes dipping into the thirties, at least over the past three seasons. Summer will have the A/C running at least to keep the humidity in check.
Isolation between the studio rooms seems pretty darned good. I have blasted the monitors in the control room and leakage to the live room is minimal. I would not expect total silence, except in a much more expensive installation.
The biggest concern I have is that, by dismantling the glass in order to clean between the panes, somehow the isolation will be compromised once re-installed.
Interestingly, as a side note, I had always been under the assumption that angled, non-parallel glass - as I have here - is the best method for sound isolation, especially if the panes themselves are different thicknesses.

Glazier is coming by this evening. I will stress the need for a fire mastic or acoustic mastic. Any particular brand recommendations?
I will continue to keep an eye on humidity levels throughout the home. Once I have actually completed setting up the studio and begin using it in earnest I will take steps to balance the humidity with an ultrasonic or steam humidifier built into the HVAC system if levels remain too low. One other need I can foresee is a fresh-air input on the HVAC System, bringing air in from outside, since there are no windows in the studio to the outside world.

Well, the guy never showed for the appointment. No call, nothing. Just blew it off and I left work early to be home for it.
This is the second glass guy to pull a no-show, bummer.
I guess I saved some money for the time being.....................

subbies are the same in aus.

with hvac you definitely need fresh air or you can make yourself real sick with a lack of oxygen. some systems (commercial grade) bring fresh air from outside. if you have that type of system then great. otherwise you will need a fresh air supply system that is fan driven. to work properly it needs supply and return or the pressure build up in the room slows down the flow.

introducing fresh air will also go a long way to fixing your humidity issues. either running your hvac in fan mode with the cooling part switched off or running standalone fresh air supply system will bring humid air in from outside. in dryer climates this might be all you need. problematic in humid climates though. so as with everything you need to keep measuring the humidity inside the space.

best to find a local installer to have a look at your current system, explain the issues to them and ask for their solution.

I am subcontracting currently, and had a customer tell me that we have been the best contractors he has ever worked with. We show up when we say and do the work we said we would. I found it odd that contractors have become so lacking! Do people just not want to work?


keymod, have you thought about seeing if you can rent the suction cup handles and remove the glass yourself?