Some additional thoughts on my part based on a few experiments this week. Many high end systems that are owned by people that listen primarily to classical or Jazz cannot put out sufficient power in the 40- 80 Hz octave range to have that feeling of really rocking (at least 95 db spl). Some of this is that many, high end owners do not spend enough money in room treatment or DSP to smooth out the room response in this critical octave. I've measured the in room response of several well constructed high end systems and many audiophiles would be shocked if they saw how uneven their bass response really is. Many rock speakers get around this by overwhelming the room with fat bass until it is really the room walls resonating that is giving the listener desired megawhomp. I find this poor bass response unacceptable on classical music and it is for classical music that I built my system, but this poor in room bass response isn't apparent to many audiophiles. I played some rock for some friends over the weekend. My system uses both the Sigtech DSP and ASC room treatment to give me a very flat power response down to 25Hz. I played Metallica, Judas Priest, Eagles and Rage Against the Machine. Using the Z-Systems DSP I rolled off or notched frequencies in the 80 Hz and below bass. At average volumes of 98 db SPL it was suprisingly easy to lose the feeling of really rocking. Even bypassing the Sigtech but with more ASC room treatment than most audiophile use, much of the feeling of rocking was lost. My conclusions are that the visceral impact of rock (at least for Metal) depends on bass power, Whether that bass power is clean or dirty matters less than its absence. Many high end systems that focus on imaging or detail can't really produce that much more acoustic power at those frequencies than many mid fi systems. If this experiment is at all generalizable moving, from a mid-fi system to a high end system will not provide the visceral impact that is critical to rock. I might add is that these capabilities are even more critical to Mahler, Bruckner, Wagner, Strauss, Bartok and Stravinsky. If you are to have anything remotely approaching the concert hall experience these composers require a flat power response to 30Hz.