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Acoustics
Sound impacts on us daily as people. As comfort and hearing quality depend on a room's acoustics, special attention should already be paid to this facet during the planning and design stage for interior spaces.
Functional, intelligently-designed acoustic solutions characterize every Armstrong metal ceiling: noise is absorbed where it could be distracting, while speech and sound is directed to where it is desired. Armstrong metal ceilings will colour the acoustic properties of a room in line with your specific requirements:
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General information about room acoustics
Sound can be divided into various types depending on its transmission method. Armstrong Metalldecken AG concerns itself mainly with airborne sound, i.e. the type of sound that propagates through the air.
The reverberation time is very important for acoustic comfort. It refers to the time duration necessary for sound pressure to fall by 60 dB after sound transmission. The reverberation time depends on the sound absorption area of a room, but will also be influenced by furniture, carpets, curtains and the number of people present. The better the absorption, the shorter the reverberation time and the lower the sound level.
Airborne sound insulation refers to the conversion of sound into thermal energy. This takes place by friction of the sound on or in the absorbent material. The sound absorption coefficient a is defined as the ratio between non-reflected and incident sound energy, and has a value between 0 and 1.
In the case of airborne sound insulation and also sound partitioning, airborne sound propagation is reduced by a solid separating element. Here, the sound energy is reflected by the insulating element and simultaneously absorbed by absorbent materials. The sound insulation values (in dB) improve as the mass of the insulating material increases.
Sound reflection refers to the deliberate reflection of incoming sound waves. The targeted use of reflective materials can help to positively influence the overall acoustics of areas.
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Armstrong acoustic inlays
Acoustic inlays will influence acoustic characteristics by virtue of their nature and their specific volume weight. Porous materials will absorb sound, while those with a high density will insulate sound. Nowadays, thin acoustic non-woven inlays are being used increasingly as their special texture functions as a sound absorber.
| Gema-Code |
Designation |
Fire behaviour |
| VLSX-A1 |
Black acoustical fleece, 54 g/m2 |
Non-flammable |
| VLS |
Black acoustical fleece, 63 g/m2 |
Fire retardant |
| AMPK |
Acoustic pad 25 kg/m3, 20mm
welded inside a PE film |
Fire retardant |
| AM |
Acoustic pad 25 kg/m3 |
Non-flammable |
| AMAF |
As AM, but back lined with aluminium foil |
Non-flammable |
| AMPKX |
Acoustic pad, film coated on all sides with polyethylene |
Non-flammable |
Sound absorption
The requirements regarding absorption for a metal ceiling can be as diverse as its application possibilities. Modified to provide the desired room characteristics, Armstrong will always offer the best performance.
Typical absorption values with Armstrong standard perforation RG 2516
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Acoustical fleece VLS, 63 g/m2, bonded over the whole surface of one side
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AMPK, 25 kg/m3, 20 mm
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Premium B 15 + acoustical fleece VLS, 15 mm, 200 kg/m3
The degree of sound absorption will depend on the materials used and any perforations in the metal ceiling. For Armstrong standard perforations, the values are as follows:
| Perforation |
Ultramicro
Rg 0501 |
Extramicro
Rg 0701 |
Micro-
perforation
Rg 1522 |
Standard-
perforation
Rg 2516 |
Special-
perforation
Qg 4025 |
| Absorption |
NRC |
awr |
NRC |
awr |
NRC |
awr |
NRC |
awr |
NRC |
awr |
| No inlays |
0.55 |
0.40 |
– |
– |
– |
– |
– |
– |
– |
– |
| Acoustical fleece |
– |
– |
0.65 |
0.55 |
0.65 |
0.70 |
0.75 |
0.75 |
0.65 |
0.70 |
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Sound insulation
Where the objective is to reduce sound propagation across ceiling voids from one room to the next, then dense or solid insulation materials should be used in the metal ceiling or placed above the partition walls.
Longitudinal sound insulation via horizontal barriers:
A combination of insulating and absorbing materials is usually incorporated into the ceiling panel to provide a horizontal barrier. The solid elements will reflect sound while acoustic inlays absorb it. The ceiling insulation value should correspond to that of the wall.
Longitudinal sound insulation via vertical bulkheads:
A ceiling may either only absorb sound, or be designed to have additional sound insulating properties. Where vertical bulkheads are used, sound propagation across the ceiling void is prevented by the installation of a barrier above the partition wall. The overall ceiling insulation value should correspond to that of the wall.
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