Exterior window treatment

[glennq]

I have a 5 feet x 6 feet exterior window that has a typical vinyl double pane exterior window in it now.My walls are 6 inches thick with two layers of sheetrock,filled with cellulose and the exterior is brick.I would like to bring the STC of the window up to whatever the walls are.I have gotten some prices on a piece of 3/8" laminated glass to mount in the interior frame of the window.I have at least 5" to work with on the inside frame.My question is would it be more effective to use the single 3/8" glass with as much space between it and the exterior window or to buy two pieces of glass,1/4" and 3/8" and use both with less space between each of the panes.My conclusion is that it would be best to use the3/8" alone an have more space to seperate from the exterior vinyl window..
Thanks

[knightfly]

I'd have a hard time improving on the answer you got from Rod over at RO, so I won't bother - other than to say, stick with the laminated glass and only two panes TOTAL, with only one air space. If possible, you want the mass of the glass in each leaf of the wall, to equal the mass of the wallboard. So, your glass panes in each side should approximately equal the total weight of that size section of your double sheet rock. You probably won't get as good STC as the wall, but it should be the best you can get... Steve