World’s first THX-Certified soundproof door joins THX-Certified QuietRock SUNNYVALE, CA — September 2, 2008 — Serious Materials today announced its new line of QuietHome soundproof doors. These new ...

This new model of steel doors boasts an STC (sound transmission class) of 58, which exceeds the STC53 commonly found in similar doors from other manufacturers. The doors are 1.75″ thick, so standard ...