JBL VRX932LA - Amplitude Shading

AMPLITUDE SHADING
Amplitude Shading
Amplitude shading is a technique that allows the coverage pattern of a loudspeaker array to be shaped by
a
djusting 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 VRX932LAs, 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
i
s unchanged but the distribution of acoustic energy to the audience is far more uniform. Amplitude shading of
a VRX932LA array may be accomplished in passive or bi-amplified systems.
Array Configuration Selector (ACS)
In passive mode, the Array Configuration Selector may be used. 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.
BI-AMP
PASSIVE
Single
Speaker
or
Short
Throw
M id
Throw
Long
Throw
A
rray Configuration Selector - HF Output Level
Equipped with Differential DriveÆ
T
ransducer Technology U.S. PATENT 5,748,760
JBL PROFESSIONAL
Northridge, CA USA
Made in USA
Serial No.
BI-AMP
PASSIVE
PARALLEL
VRX932LA
BI-AMP
±1 LF: 8
±2 HF: 6
W
W
PASSIVE
±1 IN: 6
±2 N/C
W
Single
Speaker
or
Short
Throw
M id
Throw
Long
Throw
Array Configuration Selector - HF Output Level
Equipped with Differential DriveÆ
Transducer Technology U.S. PATENT 5,748,760
BI-AMP
PASSIVE
Single
Speaker
or
Short
Throw
M id
Throw
Long
Throw
Array Configuration Selector - HF Output Level
Equipped with Differential DriveÆ
T
ransducer Technology U.S. PATENT 5,748,760
BI-AMP
PASSIVE
Single
Speaker
or
Short
Throw
M id
Throw
Long
Throw
Array Configuration Selector - HF Output Level
Equipped with Differential DriveÆ
Transducer Technology U.S. PATENT 5,748,760
Short Throw (-3 dB)
BI-AMP
PASSIVE
Single
Speaker
or
Short
Throw
M id
Throw
Long
Throw
Array Configuration Selector - HF Output Level
E
quipped with Differential DriveÆ
Transducer Technology U.S. PATENT 5,748,760
JBL PROFESSIONAL
Northridge, CA USA
Made in USA
Serial No.
BI-AMP
PASSIVE
P
ARALLEL
VRX932LA
BI-AMP
±1 LF: 8
±2 HF: 6
W
W
PASSIVE
±1 IN: 6
±2 N/C
W
Single
Speaker
or
Short
Throw
M id
Throw
Long
Throw
A
rray Configuration Selector - HF Output Level
Equipped with Differential DriveÆ
Transducer Technology U.S. PATENT 5,748,760
BI-AMP
PASSIVE
Single
Speaker
or
Short
Throw
M id
Throw
Long
Throw
Array Configuration Selector - HF Output Level
Equipped with Differential DriveÆ
T
ransducer Technology U.S. PATENT 5,748,760
BI-AMP
PASSIVE
Single
Speaker
or
Short
Throw
M id
Throw
Long
Throw
Array Configuration Selector - HF Output Level
Equipped with Differential DriveÆ
T
ransducer Technology U.S. PATENT 5,748,760
Long Throw (+3 dB)
BI-AMP
PASSIVE
Single
Speaker
or
Short
Throw
M id
Throw
Long
Throw
Array Configuration Selector - HF Output Level
Equipped with Differential DriveÆ
Transducer Technology U.S. PATENT 5,748,760
JBL PROFESSIONAL
Northridge, CA USA
Made in USA
Serial No.
BI-AMP
PASSIVE
PARALLEL
VRX932LA
BI-AMP
±1 LF: 8
±2 HF: 6
W
W
PASSIVE
±1 IN: 6
±2 N/C
W
Single
Speaker
or
Short
Throw
M id
Throw
Long
Throw
A
rray Configuration Selector - HF Output Level
Equipped with Differential DriveÆ
Transducer Technology U.S. PATENT 5,748,760
BI-AMP
PASSIVE
Single
Speaker
o
r
Short
Throw
M id
Throw
Long
Throw
Array Configuration Selector - HF Output Level
Equipped with Differential DriveÆ
Transducer Technology U.S. PATENT 5,748,760
BI-AMP
PASSIVE
Single
Speaker
or
Short
Throw
M id
Throw
Long
Throw
Array Configuration Selector - HF Output Level
E
quipped with Differential DriveÆ
Transducer Technology U.S. PATENT 5,748,760
Medium Throw (0 dB)
Frequency Response
The frequency response graph represents measurements from a single VRX932LA speaker, applying the three
different ACS settings: +3dB, 0dB, -3dB.
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