I have read Rod's book about the benefits of angled versus straight glass control room windows.
-Less ligh reflections, easier to see through
-Angled CR side might mean better sound reflection control from the front wall to the console (from Rod's book, but I am paraphrasing)
What else, and why?
Just thought I would start a discussion here amongst the local folks to see what you have all done, and why.
Window angle?
Originally posted at johnlsayers.com, topic 9662.
Aloha,
From the SAE website - http://www.saecollege.de/reference_material/index.html
Hope this helps, Aloha 8)Windows and doors require special construction because no matter how much you seal your walls if the windows and doors aren't built correctly your isolation will be ruined. The main thing with windows is that they must have the following features: * Different Glass Thickness. It is essential that the two sheets of glass be different in thickness. I recommend that you put the thicker of the two panes on the control room side. The thicker the glass obviously the better the sound isolation plus the thicker glass has a lower resonate frequency. Unfortunately thick glass is expensive. I would suggest you try 8mm and 10mm glass. (5/16", 3/8"). Any thinner and you are going to start getting resonate frequencies from the glass and inadequate sound isolation. * Angles. The two sheets of glass must be at an angle to each other else the two sheets will interact in a resonate sympathy and the sound reduction properties will be reduced. You can angle the glass as in the following drawing but don't forget that the glass can also be angled in the horizontal plane as well as the vertical plane. * Silica Beads. Because the windows are sealed the cavity created is a different temperature and humidity than your rooms which are probably air conditioned. It is therefore possible for the glass to steam up as in your car but not quite as dramatically. It is therefore recommended that you purchase some silica beads ( like you get in a little sachet when you purchase a quality camera or the like) and put them in the cavity between the glass. * Insulation. The cavity between the glass is like any space and will have a reverberant field so you must line around the cavity with insulation. The easiest way to do this is to cut sheets of fibreboard to the shapes and then glue thin fibreglass to it. Then you can wrap cloth around it for aesthetics and glue it into place. It is also a good idea to drill 25mm - 50mm (1" - 2") holes in the fibreboard in which you can put the silica beads.
I would suggest that this would only be corect if the minimum glass size met or exceeded the mass in one side of your wall assembly. Otherwise the window becomes your weakest link.* Different Glass Thickness. It is essential that the two sheets of glass be different in thickness. I recommend that you put the thicker of the two panes on the control room side. The thicker the glass obviously the better the sound isolation plus the thicker glass has a lower resonate frequency. Unfortunately thick glass is expensive. I would suggest you try 8mm and 10mm glass. (5/16", 3/8"). Any thinner and you are going to start getting resonate frequencies from the glass and inadequate sound isolation.
The above is absolutely incorrect - especially with glass of different thicknesses- different thicknesses would mean a different center frequency in which case there would be no symphatectic reasonance. In fact - angling the glass makes it less efficient as an isolator. In this xcase maximum isolation would be maximum air space - and that can ONLY be done with parallel panes So forget that explanation. But - it looks bitchin - and it does help stop visual reflectives.......... Sincerely, Rod* Angles. The two sheets of glass must be at an angle to each other else the two sheets will interact in a resonate sympathy and the sound reduction properties will be reduced. You can angle the glass as in the following drawing but don't forget that the glass can also be angled in the horizontal plane as well as the vertical plane.
Aloha,
Thank you for looking in, Rod. :D
The points mentioned were quoted from the SAE College site http://www.saecollege.de/reference_material/index.html, and if I'm not mistaken, were written by John. I only posted them because I had remembered seeing it there. :wink:
Aloha 8)
These were believed (a long time ago) to be acoutsically correct - but time (and testing) has proven them to be old wives tales......... John put together a fantastic place with the SAE - but when they bought out the site they have failed to continue to update the site as time goes on - and (from my perspective) this is a shame. We all learn as time goes on - as new products arrive - as new methods of testing shed more light on acoustic construction - or even just construction in general. Believe me - a lot of the construction techniques I use today were never a thought in my mind 20 years ago. So I am not point fingers here - just reporting the facts as they exist today. However, SAE really should take some time to bring the site into the present. Sincerely, RodAloha, Thank you for looking in, Rod. :D The points mentioned were quoted from the SAE College site http://www.saecollege.de/reference_material/index.html, and if I'm not mistaken, were written by John. I only posted them because I had remembered seeing it there. :wink: Aloha 8)
Aloha,
Thank you Rod for clarifying that, and for providing us with updated and improved techniques and information. :wink:
Aloha 8)
my window is leading outside, NOT a CR/live room window. i wanted to make sure i got some natural light in there. (comin from a dark basement studio). other than natural light it needed to block the outside noise from the cars on busy road 100ft down my driveway. 18 wheelers are loud barreling down the hill i live on.
anyway, i chose parallel in order to get the biggest airspace and the highest rating. reflections weren't really an issue, cuz i'm not constantly looking through it.
next. . .
OK, Window dilemma time!
Financially, I am struggling to finish my studio as I stretch towards the end. Based on Rod's book and the thickness of my walls (2 layers of 5/8" drywall on each wall), he recommends that I use one 1/2" and one 3/4" pane.
The 3/4" piece is REALLY EXPENSIVE!
I am thinking that I could afford to go one 3/8" and one 1/2", or alternatively two 1/2" panes. I know the recommendation seems to be to go with different thicknesses of panes so that they have different resonant frequencies, but would it be better to go with the thicker panes to give me more isolation?
Or should I just find *some* way to get the 1/2 and 3/4 panes, even if it means that my children go without Christmas presents this year? (!) ;)
Thanks!
First - I would see to it that my kids had Christmas - and I would wait until next year to get my glass if that was all my budget could afford....... :wink: . Next - I explain in the book exactly why the 2 different thicknesses of glass and the reason that the 1/2" is the smallest size....... HOWEVER - if you want the window to be the weak point of your design that's your business not mine. You could price out a sheet of 3/8" laminated glass (different reasonant frequency - different coincidence - and although not quite equal in mass to the drywall - it is equal in performance - So 1/2" annealed - 3/8" lami will give you the same as your 4 layers of drywall....... RodOK, Window dilemma time! Financially, I am struggling to finish my studio as I stretch towards the end. Based on Rod's book and the thickness of my walls (2 layers of 5/8" drywall on each wall), he recommends that I use one 1/2" and one 3/4" pane. The 3/4" piece is REALLY EXPENSIVE! I am thinking that I could afford to go one 3/8" and one 1/2", or alternatively two 1/2" panes. I know the recommendation seems to be to go with different thicknesses of panes so that they have different resonant frequencies, but would it be better to go with the thicker panes to give me more isolation?
The thickest glass I can get in the Bahamas is 1/2".
The only laminate glass is 1/4" or 7/16" "
Should I go with the 7/16" laminate with the 1/2" glass?
Does it matter which one is inside or out?
Thanks,
Clifford.
Thanks Rod. I'll do some more searching.
Clifford, 7/16 with 1/2" would work.......... the sides don't matter unless your mass on one side is greater than the other - (you know - the weird things people do - like dbl 5/8" one side - and 5/8" eith 1/2" on the other ((just because they think it makes a better wall (which it doesn't)) But with even mass it doesn't matter - it works exactly the same in both directions......... RodThe thickest glass I can get in the Bahamas is 1/2". The only laminate glass is 1/4" or 7/16" " Should I go with the 7/16" laminate with the 1/2" glass? Does it matter which one is inside or out? Thanks, Clifford.