Correlator - RME Audio ADI-96 PRO User Manual

7.6 Correlator

Function
Shows the correlation between left and right channel. Simply said: measures the phase be-
tween left and right.
Application
Checking mono-compatibility, checking polarity of microphones, detecting sound problems due
to delay and phase settings.
Settings
The Correlator has no settings, its behaviour depends on the release time set for the Peak
Level Meter. Place the cursor in the Overview window on SET and press Enter.
Menu
Options
Level Meter Release 1 dB/s up to 100 dB/s.
Typical Settings
As with the Level Meter a faster setting (100 dB/s) is preferred by most users.
This function calculates the (mathematical) correlation between left and right channel. In sim-
pler terms, the correlation gives an indication of the mono compatibility of the audio signal.
The value 1 measured with a sine corresponds to identical phase on both channels. In this case
summing the channels (mono mode, reduced channel separation or a distant listening position)
won't result in any loss of sound, the channels are 'in phase'. This is different with lower correla-
tion values. In practice values between 1 and 0 indicate problem-free material.
0 corresponds to a phase deviation of 90° between left and right channel. An indication cen-
tered around 0 or slightly shifted into the red range (0 to -1) indicates material which might
cause problems when converted to mono, or which might already suffer from frequency cancel-
lations.
-1 means out of phase (180°). In this case a summing of the channels may result in a loss of
sound, a stereo signal will completely erase itself when processed monaural.
The correlation meter can be used not only for the evaluation of existing material, but also for
testing positions of microphones or their polarity before starting a recording.
User's Guide ADI-96 PRO © RME
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