JBL VRX932LAP Portable Speaker User Manual


 
AMPLITUDE SHADING
AMPLITUDE SHADING
Amplitude shading is a technique that allows the coverage pattern of a loudspeaker array to be shaped by
adjusting the relative acoustic output of some of the devices in the array. Most often, array shading involves
only the mid and high-frequency sections of the array. In a simple system consisting of three VRX932LAPs,
the lower speaker (which covers the nearest listeners) may have its high-frequency output reduced. At the same
time, the upper speaker may have its high frequency output increased. The overall sound-power in the room is
unchanged but the distribution of acoustic energy to the audience is far more uniform.
ARRAY CONFIGURATION SELECTOR (ACS)
The -3 dB position will typically be used for the speaker(s) in an array that are covering the nearest listening
area. The +3 dB position will be used for the speaker(s) covering the more distant areas; or to compensate for
the low-frequency build-up resulting from mutual coupling of multiple woofers in an array. ( For the 0dB position
the inverse button selection yields to the same results).
FREQUENCY RESPONSE
The frequency response graph represents measurements from a single typical VRX932LAP speaker, applying
the three different ACS settings: +3dB, 0dB, -3dB.
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