2825R-XX SERIES TWO DIVER RACK
MOUNT COMMUNICATOR USER MANUAL
282XR-UM
REV 5.0
9
3.6
Option Controls: DSP3 Helium Speech Unscrambler
The controls for the DSP3 Helium Speech Unscrambler (HSU) are located in the section
immediately right of the DIVER 2 controls on the front panel.
3.6.1
On/Off Switch
–
Allows the selection of air (OFF) or helium (ON) operation. In the
OFF position, the divers’ microphone signal bypasses the HSU. In the ON position,
the microphone signals are routed to the HSU and the tender can adjust the
controls as necessary.
3.6.2
Treble Boost
–
Selects the amount of gain added to the High Frequency (HF)
portion of the divers’ microphone signals. This compensates for the HF drop
-off in
the sensitivity of most microphones. The TREBLE BOOST feature allows for
optimum frequency enhancement and improve
d intelligible speech from the diver’s
voice.
3.6.3
Depth Control
–
Selects the amount of frequency correction performed by the
HSU to produce intelligible speech. This control uses a multi-turn potentiometer
and is equipped with a turn counting knob and lock. Once the desired setting is
reached, the lock can be used to prevent accidental changes to this control.
3.6.4
Noise Reduction Filter
–
The Noise Reduction Filter (NRF) uses a complex Digital
Signal Processor algorithm based on a statistical-model of human voice activity to
capture the background noise and reduce it without affecting the divers’ speech.
The noise level can be reduced by up to 17 dB.
Summary of Contents for AMCON II 2825R Series
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