User manual

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© 2005 PANORAMAdtv ALL rights reserved
AVMFlex-SA Series User Manual P/N 821624 Rev-A
Section 2: Operation
Audio Amplifier and Speaker Configuration
General Description
All AVMFlex-SA Series modals contain high performance transducers (speakers) driven by three power amplifiers; two amplifier/driver
combinations handle midrange and high frequency information in the left and right (stereo) speaker channels, while the third amplifier channel
sums the left and right channel information below the 500 Hz crossover point in the woofer (bass) speaker(s). Note that the woofer channel
is NOT a dedicated LFE or Center channel.
Speaker Configuration
The 1U rack size AVMFlex-SA Series products are configured with two speakers (left and right) to reproduce mid- and high-range audio
frequencies (in stereo), but feature two woofer speakers to reproduce the summed (combined) low-range audio frequencies from the left
and right speaker input channels. It should be noted that both woofer speakers, which are wired in series, are driven from one woofer
speaker channel, and are NOT stereo.
See the simplified diagram below for a block diagram of the AVMFlex-SA Series audio amplifier/speaker configuration.
Balance Control Characteristics
The balance control attenuates the signal from the source, so that the left and right bass frequencies (summed together and
reproduced in the woofer channel) will also respond to the balance control.
Example:
If an audio signal of a voice speaking English is fed to the left (A) input and a voice speaking Spanish is fed to the
right (B) input, then the left speaker channel will reproduce the midrange and high-range frequencies of the English
speaking voice, the right speaker channel will reproduce the midrange and high-range frequencies of the Spanish
speaking voice, and the woofer speaker channel will reproduce the summed (combined) low-range frequencies of
both voices.
If the balance control is rotated to the left (English), then the Spanish speaking voice in the right speaker channel
will diminish in volume and the Spanish speaking voice in the woofer speaker channel will also diminish.
Note that if the balance control is rotated completely to the left, the volume in both the left speaker channel and
woofer speaker channel will increase slightly to maintain overall output level. See the simplified diagram above for
placement of the balance control in the audio amplifier circuit.
The converse of the above is true if the balance control is rotated to the right.
EQ
EQ
Woofer
Speaker
High-Pass
Limiter
Low-PassSum
Limiter
High-Pass
Limiter
Left
Speaker
Right
Speaker
Woofer
Speaker
Left Speaker
Channel
Woofer Speaker
Channel
Right Speaker
Channel
AVMFlex Series (1U) Audio Amplifier and Speaker Block Diagram
Input B
(Right)
Input A
(Left)
Volume/
Balance
(VCO)
Lo-Freq
Amplifier
Amplifier A
Amplifier B