installing studio glass

[deadroom]

Thinking about installing my window from my control room into my garage, which is being transformed into my live room as I type this.

I got a quote on a 4ft x 4ft "insulated" glass (they told me its what i needed and 2 pieces of it) at $350 without installation.

From doing a minimal amount of research i've discovered I need to have an air gap between the 2 panels of glass and that one of them needs to be at a 45 degree angle.

Would it be easiest to build the frame around the glass itself and install the complete wood/glass piece into the wall?
OR
Do you build the frame on the wall itself and fit the glass into that?

Someone mentioned in another post that the area around the glass should be filled with 703.

Is that behind the frame between the sheetrock?

I have some really handy family members (electricians/ commercial ac installers/construction ppl) so I just need to tell them what to do, give them the materials, and they actually do it.

If someone can break this down for me, i'd appreciate it!

Thank you,
Clifton

[abtech]

You may want to consider getting the 2 pieces in different thicknesses so they don't resonate at the same frequencies.

Forty five degrees is pretty steep, I usually see between 15 and 30 degrees of slant.

[deadroom]

Originally Posted by abtech

You may want to consider getting the 2 pieces in different thicknesses so they don't resonate at the same frequencies.

Forty five degrees is pretty steep, I usually see between 15 and 30 degrees of slant.

Hadn't thought of that. Thanks!

Any opinion on how to get it in the wall? haha This is stumping me b/c I want to get it right on the first try.

[xaMdaM]

The BEST illustration I've ever seen (besides my prints) is in Rod's Book

Chapter 5, pg 91, Figure 5.3

Which, by the sounds of it, you really need to get Rod's book before you do any more work.

Not tryin' to piss ya' off, but a 45 degree window with a 4' lite would be about a 38" thick wall where the opening was 24x24.

Normally you're looking at about a 2-3 degree angle.

You want the glass fully supported by the framing. If it's not, a 250-300 lb slab of glass is gonna end up on the floor, and potentially killing someone.

So, you will probably find it easiest to build the frame and install the glass in the frame.


[edit]
The resonance differences between two different sheets, while sometimes significant of a factor, is not really the main reason to do so. It's actually more important to meet (or slightly exceed) the mass/sq unit of the wall... Given that in most applications, one wall or the other will have a greater mass.

Once your wall mass becomes heavy enough, the use of different thicknesses becomes a greater factor. Often, the mass of a reasonable thickness of glass far exceeds the mass of the wall. In those cases, why spend extra when your wall is the weak link?

[avare]

Adding tot he advice you have recieved already tilting the glasss is not, needed for acousitc purposes. It is done to control light reflections and esthetics.

Andre

[abtech]

Originally Posted by avare

Adding tot he advice you have recieved already tilting the glasss is not, needed for acousitc purposes. It is done to control light reflections and esthetics.

Andre

Definitely to control reflections, particularly when both the control room and studio lights are on.

[jhbrandt]

Deadroom,

You don't need to tilt the glass. It's simply a myth. You will actually lose the transmission loss in that wall if you tilt the glass.

Ok.. lets just say that with 2 pieces of plate glass.. say 3/16" thick separated by an airspace of 4" gives you a loss of 53db.... tilt the glass a little making the airspace at one side 2" instead of 4 - you have a transmission loss of only 45db. What just happened?

Don't tilt the glass. --- Someone back in the 40s or 50s got the idea that it would eliminate early reflections in a voice-over studio while working close to the glass. - Well, it doesn't. The reflections simply come at a different angle.

-- If you need to tilt the glass to eliminate reflections from lighting... you won't need to move it more than 1/4" on one side usually.

Now it's nearly 2010 and people are still doing that because 'Elvis' did it.

Also, my friend, do you really need such large viewing windows? The specular reflections from that large expanse will have to be dealt with on both sides (and it's not a pretty graph...).

Okay, on getting it into the wall.

---If it's a dual wall construction be absolutely sure not to join the two walls. You will need to build separate frames for each glass in each wall. Fill the space between the frames with fiberglass or rock wool. Be sure to install several packets of Silica Gel to eliminate moisture. Cover the space, fiberglass and Silica Gel with a cloth or burlap. And finally, install the windows with plenty of rubber caulk.

These will be permanent. Everything must be air-tight. Glue and finish nail any trim work to finish out the window. Stain, paint or varnish to your liking.

Oh yes, and be certain to CLEAN the inside of the glass extremely well - cuz ur gonna hav' ta live with it, partner.

Good luck!

[xaMdaM]

Originally Posted by jhbrandt

Now it's nearly 2010 and people are still doing that because 'Elvis' did it.

I think more people think it "looks cool", than actually think through why they might need to tilt the glass.

In my case, there WILL be professional video crews in the studio, so getting rid of, or at least minimizing optical reflections is my reasoning... then too, I'm not using 2x4's for the walls or light weight/thin glass.

Still, no matter what the wall construction is, the lite should be at least the same mass as your wall per square unit... if not more.

And you're right about sealing the glass. Professional installers use neoprene glaziers tape. The stuff is a real PITA, but it sure does stick to things and really seals well.

If you decide to caulk ANYTHING that will be inside the glass cavity, be sure to let it cure for at LEAST a week or longer. That way, any out gassing of the caulk will prevent any type of fogging that can occur. I would NOT recommend any kind of silicone or caustic fumed caulk. I would use SilenSeal (yuk) or OSI's SC-175 as they are both pretty much made of inert materials that will cure well and have little out gassing.

[kickdrummer58]

I helped instal some 6' x 6' glass in a studio one time. it was laminated 1/2" panes I believe and that took 4 people should have used 6. but the end result looked very great. It was an old garage converted into a studio and had 4 of these windows. Heavy stuff.

On the angle issues. I have read and been taught that there needs to be a slight angle so that it doesn't become a resonating chamber. same reason we angle walls in studios. Right? or is my schooling a waste of money? wait it probably was but seriously would there not be a possibility for a resonating chamber if not tilted?

[xaMdaM]

Originally Posted by kickdrummer58

I helped instal some 6' x 6' glass in a studio one time. it was laminated 1/2" panes I believe and that took 4 people should have used 6. but the end result looked very great. It was an old garage converted into a studio and had 4 of these windows. Heavy stuff.

On the angle issues. I have read and been taught that there needs to be a slight angle so that it doesn't become a resonating chamber. same reason we angle walls in studios. Right? or is my schooling a waste of money? wait it probably was but seriously would there not be a possibility for a resonating chamber if not tilted?

I installed a 4x8x1" thick, 2 pc laminated on the CR side and 4x8x3/4" thick, 2 pc laminated on the TR side... O M G... took 5 guys straining like a mofo to put those puppies in! If we had dropped it, at least one guy would be going to the emergency room.... if not all of us.

You schooling was only a tad mis-guided. Any sealed cubic volume of air IS a chamber.

Angling any two surfaces, technically reduces the depth of resonance at f0. e.g. not as big of a hole.

By reducing the volume of the chamber, through angling, the amount of isolation is reduced, but you gain a benefit of lowering the f0 of the chamber.

You have to weigh out which one factor is the most important, then calculate the cost factor.

[Bassmankr]

The biggest reason to put some tilt to the glass is to kill some of the LIGHT reflecting off of it (making it more of a mirror than a window). Light reflection will be the worst on the side that has the most light. Why do you think birds fly into windows occasionally? Light is reflected making that window more of a mirror and bird just sees more of the outdoors. It's not uncommon on high rises with reflective glass to have someone in the morning picking up dead birds. By putting a slight tilt to both sides of a control room window you are just making it easier to see out of and into.