Firstly, Happy New Year to everyone ! Now to business :- The main function of THX, according to the blurb on their website, seems to be Re-equalisation, which (quote) "removes the edgy 'brightness' of cinema sound, accurately adapting movie sound for home playback". As most, if not all, DVD's are now mixed for home-playback from the outset, and TV broadcasts are surely the same, doesn't this render Re-equalisation unnecessary ? If you have a DVD with the THX logo, does it mean it's been mixed for home-cinema & you therefore should switch THX off, or does it mean you need to turn it on to bring something back into the mix ? Timbre-matching :- if you have similar / identical speakers in your surround set-up, this is also redundant, correct ? Bass Management / Time Synchronisation etc etc :- these are features that aren't unique to THX & are usually set-up independently (and offered on most surround-processors now as standard), correct ? THX + Ultra 2 + all the other flavours & possible combinations - what's the use of them in my AV32R DP based system ? Aren't they just a standard that's been written to compensate for "sub-standard" set-ups, or set-ups with a significant mixture of components ? At the moment, I'm going to turn all the THX options off - as I can't see they're needed for CD, or DVD, or TV, but I await any enlightening comments with interest.