Info

The directional integration begins at 5 msec to insure that the direct sound is not included. The sound pressures are taken in the 125-1000 Hz frequency range. Okano, Beranek, and Hidaka (1998) have published a graph shown in Fig. 19.11 giving the relationship between IACC and the LF. Since they are highly correlated, one can be estimated from the other.

Lateral reflections and envelopment come about naturally from rectangular halls having widths on the order of 75 ft (23 m). A high degree of diffusion is particularly helpful, along with a shallow rake to the main floor seating area, which allows the sound to interact with the side walls in a plane above the audience. Deep overhanging balconies produce the opposite effect, cutting the audience off from the reverberant field in the rest of the room since the sound under the overhang only comes from the front.

Figure 19.11 Hall-Averaged Values of (1-IACCE3) vs LFE3 as Determined in 28 Existing Concert Halls (Okano, Beranek, and Hidaka, 1998)

Figure 19.11 Hall-Averaged Values of (1-IACCE3) vs LFE3 as Determined in 28 Existing Concert Halls (Okano, Beranek, and Hidaka, 1998)

0 0

Post a comment