User Guide

132 Chapter 8 Metering
Goniometer
A Goniometer helps you to judge the coherence of the stereo image and determine
phase differences between the left and right channels. Phase problems are easily
spotted as trace cancelations along the center line (M—mid/mono).
The idea of the Goniometer was born with the advent of early two-channel
oscilloscopes. To use such devices as Goniometers, users would connect the left and
the right stereo channels to the X and Y inputs, while rotating the display by
45 degrees to produce a useful visualization of the signal’s stereo phase. The signal
trace slowly fades to black, imitating the retro glow of the tubes found in older
Goniometers, while also enhancing the readability of the display.
In the MultiMeter’s Goniometer, the Auto Gain parameter lets you obtain a higher
readout on low-level passages, by allowing the display to automatically compensate for
low input levels. You can set the amount of compensation in 10% increments.
Remember that, for the MultiMeter, Auto Gain is a display parameter only, and
increases display levels in order to enhance readability. It does not change the actual
audio levels.
Correlation Meter
The Correlation Meter provides an additional phase measurement tool that gauges the
phase relationship of a stereo signal. The Correlation Meter’s scale ranges from –1 to
+1, and different values provide the following indications:
 A +1 correlation value indicates that the left and right channels correlate 100%. In
other words, the left and right signals are in phase and are the same shape.
 Correlation values in the blue zone (between +1 and the middle position) indicate
that the stereo signal is mono compatible.
 The middle position indicates the highest permissible amount of left/right
divergence, which is often audible as an extremely wide stereo effect.
 Once the correlation meter moves into the red area to the left of the center position,
out-of-phase material is present. This will lead to phase cancelations if the stereo
signal is combined into a mono signal.
Level Meter (Peak/RMS Meter)
The Level Meter displays the current signal level on a logarithmic decibel scale. The
signal level for each channel is represented by a blue bar. RMS and Peak levels are
shown simultaneously, with RMS levels appearing as dark blue bars, and Peak levels
appearing as light blue bars. When the level exceeds 0 dB, the portion of the bar above
the 0 dB point becomes red.
The current peak values are displayed numerically (in dB increments) above the Level
Meter. The values are reset by clicking in the display.