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 . PAS-Surround Meter can be configured in a number of different ways,ballistic Nordic N9, BBC PPM, EBU PPM,DIN 45406 K-System K-20 K-14 and K-12