Actually, Tact Audio's RCS (Room Correction System) has been on the market since 1999, three years earlier than Audyssey MultEQ. The R&D work goes back to the mid 90's. It was one of the first consumer digital room correction systems on the market along with the likes of Australia's DEQX. So it's not that obscure and has had a very active user community on Yahoo!'s newsgroups since its beginnings.

However, you're correct in stating that it has never been been ported to a unit at this price point. Tact's TCS MKIII surround sound processor sells for a whopping $15K and guess what, no video processing either! Come to think of it, I don't remember it ever having been licensed to any other brand other than Tact's own in-house implementations. It's only a matter of having enough DSP power and memory for the algorithms to run properly and the lower prices in the last few years have made it feasible.