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| COMPOSITES | DAMPING |
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| Use:
To block the transmission of noise and reduce reflections from the
barrier.
Physical Properties: Consists usually of a layer of porous material and a layer of dense material. The composite material will have a performance capability as an absorber and as a barrier. Septum barriers are sandwiched between two absorber layers. Effectiveness is a combination of STC and NRC ratings. |
Use:
To reduce noise radiated from vibrating surfaces.
Physical Properties: Viscoelastic. Damping coatings take many forms. There are mastics for spraying, troweling, etc. and there are tapes and sheets with pressure sensitive adhesive. Damping treatments are sometimes combined with absorbers. Effectiveness is expressed as a “loss factor” which is the damping/stiffness ratio of a material. |
| DECOUPLED COMPOSITES |
DIFFUSION |
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| Use: To enhance the performance of the composite material when applied to the inside of an existing barrier. Decoupling creates an air space between the existing barrier and the septum composite barrier boosting transmission loss beyond what could be expected with direct attachment. | Use: To reflect sound waves off convexly curved or uneven surfaces for the purpose of evenly distributing and blending the sound over a broad area. In critical listening environments diffusion can eliminate sharp echoes without eliminating the sound by absorbing it. |
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1-610-863-6300
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Noise
and Vibration Control, Inc.
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