Martin Audio Wavefront W8CT, Application Manual

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4.10 Spaced systems
Whenever two or more loudspeaker systems are fed with the same signal and their
coverage overlaps, sound addition and subtraction will take place depending on the
listener’s position.
In the following example, the off-axis listener may hear delayed sound from the right
hand system.
The two loudspeakers are driven in phase (both were +ve just before the instant
shown) but the extra distance travelled by the second (R) signal causes it to be out of
phase at the listener position at that particular frequency (R is -ve while L is +ve).
Reflections
Remember that a strong side wall reflection will act like a second source and the
direct and reflected signal will combine as if they were two sources.
The following illustration shows what will happen. The direct signal will combine
with the reflected signal as if it were a phantom source in the position shown.
All material © 2007. Martin Audio Ltd. Subject to change without notice.