How to Choose Laminated Glass for Control Room

This isn't your usual goober-ized question.... well... I don't think so anyway.... :shock: I'm getting into the short rows and FINALLY getting ready for the glass for the Control Room/Tracking Room! (After 5 years... it's about damn time, huh?) Rod's already gotten the design worked out for the thicknesses of the glass, so that is NOT the question.... The question I have is this; The CR side of the window is spec'd as 1", and the TR side is spec'd at 3/4". In talking with the glazer, am I better off with more thinner layers of glass, or fewer thicker layers to make up the laminates? ...AND... Is it worth the added expense to use tempered layers mixed with annealed or should they ALL be tempered? The bugger to the question is that there WILL be quite a bit of video done in the facility. In talking to the glazer, he mentioned that in the tempering process, there is usually wave that will occur to the glass... the thinner the glass, the more chance for more pronounced waves. Wouldn't that offset the cost enough to go with thicker layers to avoid the chance of fogging as well as color and light aberrations? Thanks for any info or insight!

What's Rod's advise? I'd say, follow that. I'm not sure if I understand your question, but: You WANT lamineted glass, the thicker means better isolation. And you need 2 panes on a double studd wall. Not more or you 'll end up having "multiple leaves".

In talking to the glazer, he mentioned that in the tempering process, there is usually wave that will occur to the glass... the thinner the glass, the more chance for more pronounced waves.

You prolly mean the critical frequency? I'm sure Rod already imported that in the design/reccomendations.

Ahhh... I see I made myself clear as mud.... DOH! :roll: My momma always told me; "simplify, simplify, simplify".... What is better... more layers of thinner glass, or fewer layers of thicker glass? In terms of optics, fewer layers of thicker glass is better. Regardless of the number of layers, tempered glass can end up with additional ripples or "waves" in it due to the tempering process. ("waves" is evidently the common glazing term.) Taking into account that I will be doing video in the studio... is the use of tempered sheets worth the extra dollars to gain the extra LF loss, and risk color and light aberrations? (very subjective, I know... but hey.... I'll take what opinions I can get!) If so... I guess there's a pseudo permutation to the laminate process.... tempered glass only tempered and annealed annealed only Does anyone know if there is any major significance between which would be better suited for a control room environment and taking into account the use of video equipment... AND... The stoopid question of the month... in a mixed (tempered/annealed laminate) does it make a rats butt difference about which laminate surface is mounted to the room? I can't see that it would... but I've seen stranger things.

xaMdaM wrote:

What is better... more layers of thinner glass, or fewer layers of thicker glass?

It all comes down to mass and it's location. As I said, you don't want more than 2 leafs (where a leave is 1 laminated pane). so, 2 thick pieces is best (in case of a double stud wall, which I persume you have)

In terms of optics, fewer layers of thicker glass is better.

same for isolation. max 2 heavye panes.

Regardless of the number of layers, tempered glass can end up with additional ripples or "waves" in it due to the tempering process. ("waves" is evidently the common glazing term.) Taking into account that I will be doing video in the studio... is the use of tempered sheets worth the extra dollars to gain the extra LF loss, and risk color and light aberrations? (very subjective, I know... but hey.... I'll take what opinions I can get!) If so... I guess there's a pseudo permutation to the laminate process.... tempered glass only tempered and annealed annealed only

float or annealed will do fine. They are equally heavy in mass.

The stoopid question of the month... in a mixed (tempered/annealed laminate) does it make a rats butt difference about which laminate surface is mounted to the room? I can't see that it would... but I've seen stranger things.

there's no stupid questions here :) No, it doens't.

Ro, OK... maybe a pic will do a bit more to clear up what I'm talking about, because the way I'm reading your replies, it seems like you keep thinking I'm talking about two pieces of glass being laminated to fit in one singular opening. This is an old shot, but the view is from the tracking room looking into the control room... This is a room Rod perfected from my feeble sketches... so, you can be assured that there are indeed two panes of glass... One on each side of the wall... After that, I think we're on the same page, in that fewer thicker panes are better than more thinner panes, both acoustically and visually. Again, Tracking Room window is spec'd @ 3/4", and the Control Room side @ 1"... size is approximately 48"x96". As tempered would cost a bit shy of another arm and leg I can't afford, I'll probably just do annealed laminate; two-3/8" for the 3/4" piece and two-1/2" for the 1". Granted, the vinyl carrier will make the widths a bit more than the specifications, the glazer knows he'll have to measure and account for the additional thicknesses when he measures. The glazer I spoke to said that it'll take 2-3 weeks to come in, once we order it. So, I'll kinda watch and maybe bump this thread over the next coupla' daze to see if anyone can offer a better argument that might sway that decision before I have him come out and measure the opening. Thanx! Max (You know... I can tell I'm getting tired of this build... I used the same two terms for opposite meanings... and then overlooked em' BOTH!)

so if I understand your re-re-re-re-stated question, you are asking of it is better / worse / the same thing to specify that your 1" laminate is made from two panes of 1/2", or three panes of 1/3", or four panes of 1/4" or 8 panes of 1/8"? Or maybe even a combination of the above, such as one 1/2" plus two 1/"? Is that it? Good question! It hadn't even occurred to me that you could get a laminate pane made up like that, but if so then it makes sense, thinking about it. I honestly don't know for sure, but I'd hazard a guess and say that maybe, just maybe, there might be a little more isolation in several layers than in just two layers. My reasoning is that, since the laminate material acts as a damping layer between the panes, then having two or three of those damping layers might buy you a little extra isolation, and perhaps using differing glass thicknesses would also help another little bit. But I'm just guessing out loud here. I may be totally wrong. Maybe Rod will drop by and see your question, because I reckon he's the one who would know. - Stuart -

Yeah Stuart... you got it! What I'm evidently finding out is that when you are talking about glass much thicker than 1/2", it's much more likely that it WILL be a laminate... mainly because it's easier to find glass thinner than 1/2". Not only that, but evidently this becomes even more common when you get above certain sizes... Not sure where the break over point is. I understand what you're thinking is, in regards to more sheets of laminate... the more damping from the vinyl carrier sheets... which is kinda' the devil's advocate question I was posing. As a side bit of trivia, I found out that there's two standard thickness' of the vinyl carrier... .03" and .06"

Okay, I understand now. I hope :) I'd go for a 2-piece laminated glass pane. A thick sheet has lower resonance than a thinner piece. Multiple layers of DIFFERENT thickness will overlap in resonance, sure, but you want to have those as LOW as possible. Altho the TOTAL thickness is actually what your resonance will be since the 2 pieces are laminated together. (sigh) Since a laminated pane made out of 2 pieces of glass (with a layer of PVB in between) will be better, visually, and prolly a whole lotta cheaper too, I'd go with just "standard" laminated glas. Meaning; 2 pieces of floatglass with a dampening layer in between. The glazer will know exactly what the end result in thickness will be. A PVB layer can be different in size and stifness. I think you'll end up with a 1-1,5mm layer. It doesn't really matter on which side you put the glass. 3/4 on CR or tracking and 1" the otherway, doens't really matter. AS long as the total mass equals, or better exceeds, the wall mass.

Ro, Sorry to have been so cornfuzzeling... :shock: I guess I was hitting on too many variables to make myself clear. My apologies... I post a lot in other forums, and man... it does get frustrating when posts aren't clear, and you get going one way, when the poster was talking about something completely different. (If you think this was bad.... imagine what poor Rod's been dealing with!!) I owe that man MORE than a coupla' beers and aspirin.

Some of us who may not deserve a beer may still like one! Remember, man cannot live on construction alone!

xSpace wrote:

Some of us who may not deserve a beer may still like one! Remember, man cannot live on construction alone!

Don't I know it! :mrgreen: We've been working on perfecting Black and Tan's as part of the building process! Well... There's been some window related posts as of late, so maybe this will tie in... The glazer I'm working with has gotten back to me with pricing yesterday. It looks like both of the pieces of glass for the control room, are going to be able to be had as 2 equal thicknesses for each piece. The 1" piece for the control room side will be just over 1" and the 3/4" piece will be just under 3/4". The cost of using tempered glass is just too high. At just over $1100 for the 1" thick for non tempered, I was told that to temper a piece that big (48"x96") would add something like $300 to each piece.... OUCH! So... equal thickness, non tempered laminate is what's going to go in.... again, unless someone can definitively argue/justify a reason to use more pieces of thinner glass to create the laminate. Thanx! Max

Good decision. You don't need tempered glass, just 2 pieces of floatglass. pref different thickness, but that's optional. 1" is heavy :)