At this software it concerns a combined level and correlation meter for Surround signals for the 5.1-Standard.

The levels of all six channels as well as the phase correlation between all combinations of two channels are represented, so that defined statements are possible for the mono compatibility of a stereo and a Surround signal, in addition, for the Stereo compatibility of a Dolby Prologic signal or a 5.1-Signals in the Downmix.

PAS-Surround Meter can be configured in a number of different ways, to accurately model the ballistics, responses and graphics of a wide range of standard peak programme meters. These meters currently include the following:

IEC 268-10 Type I - Nordic N9
IEC 268-10 Type IIa - BBC PPM
IEC268-10 Type IIb - EBU PPM
DIN 45406

Provides information about mutual phase-frequency relations between the signal of the left and right channel and allows us to spot any possible irregularities. These 'irregularities' may not have any significance in the case of stereo playback, but it should be remembered that the material we record can also be played as a mono signal (for example, on TV or on one of the radio stations which are broadcast or received in mono), and is worth sounding at least similar to what we imagined. However, you have to learn to read the indications of the correlation meter.