Electro-Voice EVF/EVH EVF-1151S - Manual (Page 18)

Electro-Voice EVF/EVH User Manual 18
Finally, another way to reduce interference is to apply signal delay of up to 8 milliseconds to one of the
two systems. This requires a separate DSP (digital signal processor) drive to the delayed system. Figure
10 shows the dramatic smoothing achieved at 1,250 Hz. Note that the systems are still close together as
in Figure 6.
Figure 10:
Horizontal polar response (blue center plot) of two closely clustered 60° x 40° loudspeakers aimed 60°
apart, showing the smoothing of multiple-source interference caused by a 3-ms delay to one loudspeaker
3.0 Designing an EVF/EVH Cluster (cont’)
In clusters with more than two systems, adjacent boxes are usually delayed. While the effect can be
predicted with appropriate software (such as EASE 4.2), the actual delays are typically established in the
field during system setup and commissioning, by ear and measurements.