User`s manual

MSD100 Series - User’s Manual

4.2 Phase Correlation Meter

The Phase Correlation Meter displays the average phase

relationship between two audio signals, and indicates

mono, stereo or reverse-phase on a centre-zero scale.

Table 4-1 and Figure 4-3 describe optimum stereo and

mono signals measurements and corresponding displays.

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Note: Input signals below a predefined threshold

will force the indication toward zero. Only major

phase components are considered.

4.3 Audio Vector Oscilloscope

The audio vector oscilloscope, also know as a stereo

image monitor or goniometer, provides continuous

Lissajous-format display of the phase and amplitude of

the stereo signal.

An ideal stereo signal has phase and amplitude compo-

nents randomly distributed.

The best example of a true stereo signal is from an audi-

ence applauding during a live recording. This is repre-

sented graphically on the oscilloscope as a perfect circle

or ball, as shown in Figure 4-3.

See the examples of phase meter and oscilloscope dis-

plays under different signal conditions in Figure 4-3.

Signal Ideal Display/Comment

Stereo [0] Perfect circle or ball. See Figure 4-3.

This representing a random distributed

phase with maximum ambient effect.

Mono [+1] Vertical straight line. See Figure 4-3.

A [0] to [-1] indicates signal with

reversed phase components approach-

ing a horizontal line displayed in

Fig. 4-3.

Note: Never allow a negative reading if

the signal is to be reproduced in mono.

TABLE 4-1. IDEAL STEREO AND MONO SIGNALS