Soundproof Windows Overview
STC ratings denote how much sound is stopped by a barrier, such as a recording studio window. Being the only way to compare various sound blocking materials, this rating is used for windows, doors, walls, etc. Normal windows have STC ratings that range from 18 to 38.
STC checks the amount of sound stopped in 18 different frequencies, in a measure of decibels. These are based on a logarithmic scale, which means every subsequent number is significantly higher than the one before it.
What are STC ratings for windows?
Single pane windows, more common than the recording studio window setup, land a rating of 26 to 28. The two-point difference can be because of the thickness of the glass, and the air tightness of it.
From dual pane windows, the STC can go from 26 to 33. These windows come with fairly decent air seals, and it is the glass thickness and the intervening air which decide the amount of sound blocked. Glass panes fixed bigger air spaces are preferred.
For the soundproof recording studio window, the STC ranges from 48 to 54. The variance derives from the existing windows, as well as the air space. A single paned soundproof window in a standard wall is at the lower end of the range, while double paned windows would have a higher rating. With more air space between the panes, it is possible to have reduction ratings over 50.
About Soundproof Windows
STC rating numbers do not go very high, because each whole number increase signals a significant raise in sound blocking capability. For example, a transition to 38 STC from 28 STC is a 90% noise reduction, while 43 STC from 28 STC takes out 95% of the sound amplitude. Every nest number stands for a much larger amount of noise.
Dual panes stopping noise
This doesn’t happen noticeably well. STC 35 windows replacing STC 27 windows won’t take out the noise by much. Actually, it takes STC 40 or higher to make noise a peripheral concern. That is because at this point, it is harder to hear the sounds because of the reduced volume. The sensitivity of the human ear doesn’t usually stretch that far.
And a 100% reduction is very hard, in that only the very best recording studio window can manage it. In most cases this is moot because the walls would transmit sound, even with STC of 43-48. Soundproof windows are much better at blocking sound.