We are often asked why we are so picky about sound isolation and STRONGLY encourage our clients to have us do the room construction.
The first answer is we must get the noise floor in the room to 21dBA in order to preserve the full dynamic range of any audio recording (music or movie) and at the volume intended by the artist, sound engineer or director. (Too loud is one of the reasons many home theaters fall into disuse.)
The second answer is isolating the room from outside noise requires precision, strict attention to detail, and, more importantly knowledge, precision, and construction techniques that are not known, misunderstood, based on internet mythology, or inappropriate by the vast majority of contractors that don’t do this everyday. One of the reasons we build to 1mm accuracy and manufacture our own doors. Just recently I caught a to the point post by my respected friend Norman Varney that brings this point home. I’ve included it below:
“From an STC point of view, it’s only as good as the weakest link in the chain. For instance, a sound leak area of only 0.0001 times the surface area for an STC 60 wall, the STC cannot exceed 40. The opening for the lights and the speakers need to have the same construction as the primary. Do not forget about the door!”
