search_all
Home Soundproof Garage - Garage Conversion Stage 3 Soundproof a Room Stage 3 Part 1
Soundproof a Room Stage 3 Part 1

soundproof airtight ducting ventilation breathe safety Soundproof GarageBecause the room needs to be sound-proof, in the simplest sense, this means that the room must also be air-tight. Obviously, an air-tight room is not practical, so ventilation has to be achieved without compromising the sound proofing. There are three principles that must be followed here:

  1. Always aim to move a large volume of air slowly, rather than a small volume of air quickly.
  2. The inside surfaces of the duct should be non-reflective. This is to damp any internal resonance that may occur in the duct, and eliminates the droning sound that can often be heard in ventilation ducting. The effect of the internal damping within the duct will not however overcome any problems created by violating the first principle.
  3. There must not be a direct line of sight from the sound source to the outside world. In other words, you should always move the air around at least one 90 bend.
First duct section between the outer wall and the fan position

Here is the one area where I am unhappy with the design I used. The ducting should have been made from MDF board and lined on the inside with an open-celled, non-flammable foam such as glass fibre duct lining or melamine foam.

The problem I have was created by leaving the inner faces of the ventilation duct hard and smooth. This means that when the fan is running at full speed, you can hear a droning note created by a standing wave in the duct. This is really annoying, so I will be replacing the fan duct with one that is lined correctly.

The foam lining inside the duct acts as an absorber, and sufficiently damps the standing wave created by the fan that you cannot hear it anyone. You may still hear air movement if you run the fan too fast, but there will not be that annoying droning pitch caused by a standing wave within the duct.





Articles by this Author:

Soundproof a Room Stage 1  Part 4Soundproof a Room Stage 1 Part 4
So we're done then? NO! You've only solved one problem! Sound proofing your room will keep everyone outside the room happy, because you have stopped sound escaping and therefore annoying everyone....
Read More >>
Soundproof a Room Stage 5 Part 4Soundproof a Room Stage 5 Part 4
Fabric Finishing The inner surfaces of the room cannot obviously be left with exposed Rockwool, so they will be covered with fabric. The fabric I used was the following: For the ceiling, white cotton...
Read More >>
Soundproof a Room Stage 5 Part 2Soundproof a Room Stage 5 Part 2
Internal Insulation If you remember back to the design stage, I mentioned that there were two problems to solve. The first was to stop sound escaping from the room, and the second was to control...
Read More >>
Soundproof a Room Stage 1 Part 1Soundproof a Room Stage 1 Part 1
The problems When building a music practice room, the most important problem to be solved is stopping sound from escaping. If your practice space leaks sound like water through a sieve, then this...
Read More >>
logo footer   Designed by Marshallarts (c)1999-2010 - All Rights Reserved