acoustics - soundproofing and acoustic treatment

Acoustics (SOUNDPROOFING AND ACOUSTIC TREATMENT - OVERVIEW)

Prepared by Engr. Robert James Bedaño

Where to Start? Most of often problems in Room Acoustics are summarized in this two points

Isolation: Soundproofing

WALLS

CIELINGS and FLOOR

DOORS AND WINDOWS

CHECKPOINTS

WALLS Walls serves as the barrier from the outside of the room. Thus it plays a great part in isolating or soundproofing a room. A large part of that describes how well a barrier(wall) deflects sound’s energy rather than absorbing it has to do with its weight; that means the heavier the wall , the more energy it will deflect.

WALLS

Solid walls like in the examples in the previous slides , also has some disadvantages;THEY TRANSFER ENERGY VERY EFFICIENTLY AT THEIR FUNDAMENTAL RESONANT FREQUENCIES. So having only thick walls does not totally provide us a good isolation. But heavier and solid materials are still more efficient than softer materials.

That being said, we will now discuss ways to solve or lessen the issue of material resonance.

WALLS One solution to the resonance issues is to use materials specially designed to have great mass, yet soft enough to decrease the effects of resonance. An example of these materials is the MLV, or Mass Loaded Vinyl.

However , these materials are expensive. So another solution has to be introduced if budget is an issue.

WALLS Another method of alleviating the resonance problems of solid walls is DAMPING. DAMPING is basically converting sound energy into other forms (HEAT) to lessen the transmission/propagation of the actual sound. One way to damp sound is to use double layers of wall (dry wall, ply wood , etc.) and then sticking them together using a acoustic damping compound (like a glue). This acoustic damping compound will convert any vibration (caused by sound) into heat.

Imagine a sandwich with the wall as the bread and the damping compound as the sandwich spread.

WALLS

WALLS - DECOUPLING Decoupling is a method isolation that solves the problem of transfer of energy in solid objects. The main idea of decoupling is to separate the inner wall from the outer wall to minimize coupling (transfer of sound)

WALLS - DECOUPLING with Resilient Channel

WALLS - DECOUPLING with Resilient Channel

WALLS - DECOUPLING

WALLS - DECOUPLING

CEILINGS

For sound proofing on ceilings, it is highly recommended to

follow the steps/tips provided for the walls.