Page 199 - Master Handbook of Acoustics

FIGURE 10-10 For a group singing with multiple microphones, if d is at least three times greater
2
than d , the comb-filter effect is minimized.
1

Example 4 Figure 10-11 shows dual monaural loudspeakers, for example, one on stage left and the
other on stage right comprising an auditorium sound system. Two sources radiating identical signals
create comb filters over the audience area. On the line of symmetry (often down the center aisle),
both signals arrive at the same time and no comb filters are produced. Equi-delay contours range

out from stage center over the audience area, the 1-msec-delay contour nearest the center line of
symmetry, and greater delays as the sides of the auditorium are approached.

FIGURE 10-11 In the common split system in which two loudspeakers radiate identical signals,
zones of constructive and destructive interference result which degrade sound quality in the audience