'Soundproof' windows...good or bad idea?
Has anyone had any experience with "soundproof" windows? These are windows that mount inside one's current windows. Supposedly, they cut sound by 75%+ (stc in the high 30s/low 40s), help with energy savings, and dust. I am interested in their sound reducing abilities. The idea behind them makes sense to me as I've heard airspace is what's important in stopping sound, and these would create a 2-4 inch barrier between the two windows. I would think this is better than the airspace created with good double panes.
I have a 14 year old house that has what I think are builder grade single pane windows. As far as I can tell, they seem to be fully functional and are in no need of replacement due to being worn or broken. The noise problem is not severe, just basic neighborhood traffic. However, I have an open floorplan, and noise from the front of the home pretty much travels throughout the house. I was curious as to whether installing these windows on my front windows would help my issue. I prefer not to go through the expense of replacing my windows, especially if these would actually do a better job.
For more info on these windows...
I am thinking of ordering from...
I have searched the internet for unbiased reviews, and there is not much out there. Some positive, some not. I think the performance of these windows would depend on other factors (i.e. if one's home is old and has no/poor insulation, no window is going to solve a noise problem). Since my home is relatively modern, fully bricked, and insulated...I am thinking windows are the primary transfer of noise into the home.
Anyway, does anyone have any experiences...personal or hearsay? Is the idea/technology behind this kind of window a sound one (no pun intended)?
I appreciate any advice!