Page 238 - Master Handbook of Acoustics

FIGURE 11-23 Room conditions and calculations for reverberation example 2.

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An average reverberation time of 0.54 second in a room of 3,728 ft volume would be quite
acceptable for a music listening room. If it were decided that the 0.85-second point at 250 Hz
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should be brought down closer to 0.54 second, it would require about 100 ft of an absorber tuned
to 250 Hz.

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How should the 340 ft of 3/4-in acoustical tile be distributed? For maximum diffusion it should
be applied in irregular patches and distributed to the three axes of the room. As a first approach, the
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340 ft could be distributed in proportion to areas on the three axes of the room as follows:

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Area of N and S walls = (2)(10)(16) = 320 ft (21%)
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Area of E and W walls = (2)(10)(23.3) = 466 ft (30%)

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Area of floor and ceiling = (2)(16)(23.3) = 746 ft (49%)