User manual

I/O CALIBRATION AND SYSTEM SETUP ENG
Page 39
20.4 VOICE CONTROL (ST AND FM VERSIONS ONLY)
Some human voices (particularly male voices) exhibit as much as 6dB asymmetry in their waveform, while typical
‘musical’ signals are symmetric.
As asymmetric clipped signals result in a more unpleasant ‘sound’ to the ear than the symmetric clipped ones, a filter
designed to convert asymmetric waveforms into symmetric ones would be very recommended. Even better, it would be
highly recommend to pre-process the live speech (as captured by studio microphones) through dedicated VOICE
PROCESSORS, that are situated between the microphone(s) and the broadcast mixing console (see figure).
Whenever no voice processors are available and the ‘speech’ material (as sourced by microphones) is directly
passed to the processor inputs, You may activate a phase rotator input stage, also called ‘Voice Optimizer’ that
removes the asymmetrical waveforms from the incoming audio signal, thus giving significant improvements on speech
processing and removing any distortion
.
Although the ‘Voice Optimizer’ stage is a special all-pass filter designed to properly modify live speech material, it may be
set as ‘enabled’ even when ‘music’ signals are processed, as it doesn’t affect in a perceivable mode the most part of that
kind of signals. However, we suggest to keep it off in every ‘all music’ station, when no live speech interventions are
performed.
To enable the Voice Optimizer stage:
DEFAULT SCREEN
INPUT CALIBRATION menu
VOICE MODE page
The Phase Rotator stage performs 1 msec Group Delay at low frequencies in respect of medium frequencies.
This results in a phase rotation centered on 600 Hz frequency.