Ideally there should be no physical contact between each sheet of glass or wall frame.
Yes, use two different thicknesses.........6mm (1/4") and 10mm (3/8") are fine, but put the thicker at the sound source side.
Using laminated glass is preferable, as by nature (it is two thinner sheets with a clear synthetic membrane between), it doesn't have the tendancy to resonate as much as normal "float" glass.
Acoustic tests have shown that angling the sheets is of little value unless they are of the same thickness, and then to be of any use the angle should be at least 12 degrees. Angling does reduce problems of light reflecting back and forth between the sheets and it definitley looks cool.
i don't wanna do that... i tried it with x-10's.. the mic booth is gonna be right infront of me so i'd rather have a window... we'll get 1/4 and 3/8'' then....no ? is were can i buy it? and how much ...the booth is gonna be built out of mdf with acousic foam and bass traps
this is only gonna be a temp booth until this fall...
instead of using 2 peices, what about just 1 sheet of 1/2" plexiglass or 3/4" car stereo plexiglass... i order stuff from select products all the time... http://selectproducts.com/frameindex.htm
i was thinking 3/4" plexiglass would work fine for this temp booth..anything is better than the closet i'm using right now...it has a smooth sound but not a lot of space...
i don't wanna do that... i tried it with x-10's.. the mic booth is gonna be right infront of me so i'd rather have a window... we'll get 1/4 and 3/8'' then....no ? is were can i buy it? and how much ...the booth is gonna be built out of mdf with acousic foam and bass traps
Like others said, any glass place. However, i would highly recommend SAFETY GLASS. Its worth the money in preventing people from getting injured should anyone fall into it.
i haven't started on my vocal room yet....but i have a really big sheet of glass (not lamenated). I was just going to take the sheet of glass to the glass place and have it cut in half... for my 2 peices of glass for the observation window.
Glass of a given size and thickness will resonate at a fairly specific frequency. If you have two sheets the same set parallel to each other, the one on the "sound source" side will set up "sympathetic frequency resonation" in the other sheet. This is why it is preferable to use sheets of differing thicknesses, so they are not in sympathy with each other.
One way to minimise this effect is to mount the sheets out of parallel..............try and get them at least 12 degrees offset. And the thicker the better.
the angle thing is really just for the parelell wall avoidance, and the fact that it is less likely to cast a reflection, so vocalists wont look at themselves while they should be paying attention to you.
Differing thicknesses resonate at different frequencies. so sound doesnt tend to go through them as eazy.