TacT calls it Dynamic Room Correction. Works just like the Audyssey equivalent, except that the 12 base loudness curves (FM, refined by Robinson & Dodson 1956) can be edited by the user. Dunno the granularity 'cuz I've never done it, but I would assume it's the same as the basic FR target curve, which is 1Hz, 0.1dB increments. Interpolation on the fly between the twelve curves for every 0.1dB change in volume.Are you saying the TacT allows for volume-based graphic eq? Maybe I'm missing your point. That would certainly be pretty nifty... to adjust the curve (at some number of Hz steps presumably) for each and every dB step of the attenuator's range.
Problem with any kind of FM-based approach for 2ch (unlike movies) is that there are no standards for actual volume i.e. 85dB perceived by the listener could be -15dB, -8dB, -22dB or any other setting on the preamp, depending upon the CD in play.