We soundproof windows, and sliding glass doors. Whether hotels or residential – we increase existing window STC values from 25-30 up to 50-55 STC. We add a second operable acoustic window to achieve these results. We can resolve even train noise problems. For recording studios we have windows and sliding glass door assemblies with STC values of 64-65! Our steel swing doors have an STC of 56 in a standard 1.75” thickness. We can resolve your noise problems. We ship and install nationwide.