Thanks Kal.

I have a further finding. Playing 2 channel DTS encoded material into the Multi Digital input results in the G61R correctly identifying it as a DTS stream and automatically selecting the DTS decoding DSP. Using a DTS channel identification test reveals that the 2 channel DTS is decoded correctly. This is not mentioned in the user manual, so I consider it a 'hidden feature'. When playing DTS encoded material, as well as the automatically selected DTS decode DSP, both 'Cinema' and 'THX' and 'Discrete' settings are available. 'Cinema' and 'Discrete' (with default settings) appear to treat the DTS stream identically to the DTS setting and have no additional effect, THX appears to add some 'air' or 'width' to the soundstage, but in all these settings, the DTS stream is still correctly decoded.

Oh, just to clarify one point in my previous post regarding how the G61R routes channels 3 and 4 to the rear speakers with 4 channel audio. The G61R Manual says the 2+2+2 setting:
Quote
Allows you to specify how DVD Audio channels 3+4 should be interpreted: Off ignores them, 5.1 and 7.1 use them for centre and LFE, Side uses them for the side speakers, 7.1 adds side speakers to 5.1.
As I say, this is incorrect. With four channel material (from a non Meridian source), 3&4 are sent to RR & RL even when the 2+2+2 setting is set to 'off'. (I don't have side speakers so am unable to test what happens with a 7.1 layout).

I don't have an HD621 or UHD722 so I am unable to test if these features are available using them. Also, I only have a G61R but it wouldn't surprise me if other G or 800 series surround processors also support these 'hidden' features.

Ali.

Meridian G61R, Behringer A500 amps & DEQ2496 DSP, MiniDSP U-DIO8 audio interface, B&W DM2 Mk2 Speakers (3 pairs), Sony CD, Sony DAT(x3), Alesis Hard Disk Recorder, Sony APR5003 Reel to Reel Recorder. Akai AT93 Tuner & GX-95 MK2 Cassette Deck, Technics SL-1200 Turntable, Valve Phono stage, Denon DL-110 cartridge.

Ambisonic user since the 1980's