urban, yer idea of having two separate systems has too many wariables as presented, to be able to draw any conclusions.
1st of all, what exactly do ya mean by "multi-channel"? a h-t set-up is vastly different than one designed for audio, w/ambient-room info as the only program material used for the *other* channels. and, afaik, the audio unit i have is s.o.t.a. for that type of multi-channel audio-only processing, & it's now almost 10-year-old technology. like it or not, (& i happen *not* to like it), audio-surround has wirtually disappeared from the market-place - anyone know anything different? that said, i'm conwinced that multi-channel optimized for audio will absolutely crush multi-channel optimized for h-t, even tho the h-t processing technology is current technology. i'm talking of listening to *music*, of course.
whether or not audio-designed multi-channel will sound better than 2-channel is wery dependent on the music chosen, imho. for example, my re-mastered winyl copy of little feat's live *waitin' for columbus* sounds great w/my surround-processor engaged, set to "outdoor pawillion". but, patricia barbour's *cafe blue* sounds much better w/the processing off then when set to "yazz club" on the processor. to try & cross-compare, little feat sounds better w/*no* processing than patricia barbour sounds *with* processing. then again, my room, at ~25x38, is *great* for 2-channel; smaller rooms wood prolly benefit more from multi-channel ambient processing...
bottom line for me - if i had to choose between *always* using my processor, or *never* using it, it'd yust have to go away! ;~) as far as h-t surround goes, well, it's not an issue for me, as i don't like watching movies. but there's *no way* i'd *ever* run 2-channel audio thru a multi-channel h-t set-up - i'd either have 2 separate systems, or run my h-t processor thru a bypass loop now so commonly awailable on top-line 2-channel preamps. (gee, if audio is so good thru multi-channel h-t, i wonder why these by-pass loops are becoming so popular on all these audiophile preamps?!?) ;~)
regards, doug