Soundproofing is also known as ‘Isolation’ for the simple reason that it stops sound from disturbing people inside the house or around you. Soundproofing is also important because it stops all the noise from coming into the room and ruining your jam. In the mixing room (also known as control room) it is essential to keep the noise-floor to a minimal level so it’s not just concealing the details but also restricting dynamic range of the room.
Let’s just say you have a home theater system that is capable of 100 dB optimum output. In a normal room without soundproofing, the noise floor will be usually around 50 dB. Things like HVAC fans, people around your house, sound coming in the room through the windows etc. all contributes to this. In that case, the maximum dynamic range your system can achieve is approximately 50 dB. But if we build a room where we do focus on soundproofing, we can get down the noise-floor down to 20-30 dB. If the noise-floor does come down to 30 dB and we have the same equipment, we can easily achieve a dynamic range of 70 dB. This concludes in more dynamic range, it takes less to maximize as the equipment is loud enough to hear smallest of the details.
Sound travels through 2 ways, i.e.: through air and through structure.
Sound that travels through air is comparatively easy to understand. With any accessible holes in the room and the sound leaks. Outlet, switches, canister lights, gaps underneath the door, HVAC ducting, etc. are all very clever and admirable sound transmission paths. However, sound travelling from your structure is much less understood. Sound vibrates through walls, ceiling, floor or even tin ducting! When they are caused to vibrate by the sound in your room, the other side or what they are connected to also creates vibration and recreates that sound in other parts of the rest of the structure. If you think that concrete basement floor isn't a flanking path for sound to get to the rest of the structure, you are wrong! Flanking is a term that is used to explain a path where the sound ‘goes around’ the barrier of the space.
So in this case, how does one deal with problems of soundproofing? It all comes down to your budget, situation and whether the room is already built or not. Let’s take an example to make the issues of soundproofing more subtle and easy to understand.
Your existing room is to be used for a listening room or to put up with the home theater in the room. Bedrooms are not precisely next to this room but are close enough that transmission of the sound can become an issue.
Let’s see how we can tackle this and make it sound proof.
All that you have done in Level 1 of sound proofing, you can add some more to get better performance gain.
While level 1 & 2 can give you great performance gain, level 3 makes soundproofing extremely easy!
Even with so many efforts, there will still be some moment. But with all the soundproofing, it all acts like one big woofer!