Just wondering whether upgrading 1940's single pane windows to modern dual pane windows would/could change the acoustics of a room.

Specifically, I'm in the process of doing this window upgrade in my living room right now. There are two windows roughly behind the speakers (a few feet offset), and windows on both sides of the room. The room is also L shaped if it matters.

Doubtul.

Do you have curtains or some other covering over the windows?

Good question.. Dual pane glass keeps sound from coming in, and going out.. more insulation than a 70yr old window.. I would say it's possible? Are you going to go with a higher end window like Anderson or HD special?

Currently have very thin (mostly transparent) curtains, but they are seldom used. Will having thicker curtains help acoustically?

Will having thicker curtains help acoustically?

It depends on whether the windows are at reflection points. But generally, yes!

--Ethan

Good question.. Dual pane glass keeps sound from coming in, and going out.. more insulation than a 70yr old window.. I would say it's possible? Are you going to go with a higher end window like Anderson or HD special?

Yes, I'm putting in Marvin wood windows with 1/4" laminated glass over 1/8" annealed (Low E II + argon). One of the main goals was sound reduction because the old windows let a lot of outside noise in.

Would this help or hurt the acoustics?

Currently have very thin (mostly transparent) curtains, but they are seldom used. Will having thicker curtains help acoustically?

It depends on whether the windows are at reflection points. But generally, yes!

--Ethan

They will help cut down on "slap" echo in the room. I have a sliding glass door behind my LCD tv and front speakers. I have heavy curtains behind and to the side of the tv and speakers. There is a noticiable reduction in echo with the curtains closed compared to open.

Yes, I'm putting in Marvin wood windows with 1/4" laminated glass over 1/8" annealed (Low E II + argon). One of the main goals was sound reduction because the old windows let a lot of outside noise in.

Would this help or hurt the acoustics?

Acoustics will be affected by the reflections off the glass. I doubt high frequency reflections will be any different simply because they are lower in energy and will just bounce off the glass. Mid and low frequencies may be affected due to the addition stiffness of the new glass. The glass will flex less allowing more energy to be reflected rather than be transmitted through the glass to the outside. What the actual impact would be, I do not know.

I say yes, but it's not a definitive yes on the room acoustics, but the new windows will definitely not let as much sound out.

Just kind of an insight on single vs double pane - I have single pane glass in my house (5 yrs old) and can hear the stereo 10 ft from my front door.. neighbors next door have double pane and you have to be up next to the house before you hear anything.

Now I am second guessing the single pane glass in the bedroom. Thanks. :)

It can. For sure!! I put in all new double pane primes. I used windows with the grills inside between the panes. Some of them resonate! I also have one that the spring balance inside the wall resonates. On a rare long note, they get going. Does not effect the EQ of the room at all, if that is your question.