I missed out the Holst planets Mars. What I heard there is best summarized by Ron's comments below extracted from his review:
Postscript: I visited Steve today to catch up with I'm before I go back to London. I brought with me a CD of the Genesis album with the “Drum Duet” track -- with Phil Collins playing the drum kit on the left side of the stage and his colleague playing a drum kit on the right side of the stage. (Henk very kindly gave me his CD of that album.)
When the track was finished at Henk’s place my wife and I turned to each other and each of us basically said “Oh my God, that was amazing!” So I was really curious to hear this drum track on Steve’s very full-range and bass capable system. (Steve supplements his big Wilsons with JL Audio Fathoms.)
On Steve’s system the drum track today was very good but it was not involving and mesmerizing like it was on Henk’s system. Listening to the drums on the Grands seemed to my wife and me like an experience.
This is absolutely no criticism of Steve’s system. As I have written many times I love the sound from Steve’s system. I am very confident what I heard from this track on the Grands versus on conventional cones means that Kedar was correct about the amazing bass reproduction on the Grands: the woofer panel on the Grands -- which covers about 70 Hz to about 250 Hz -- is the best reproducer of that frequency range I have ever heard in my life. I do not think any dynamic driver speaker -- not Wilsons, not Genesis woofer towers, not Pendragon woofer towers, not any set of cones -- is going to reproduce 70 Hz or so to 250 Hz or so with the articulation and realism and power of those big, trapezoidal woofer panels on the Grands."
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well ok. here we go.
the MM7's have -4- 11" ceramic woofers per tower which cover 40hz (rolled off into the mid-20hz range) to 250hz. plus -4- 'active' 15" drivers that cover 7hz (3db down) to 40hz. the -4- 11" ceramic drivers are 96db 6 ohm efficient.....so lots of driver surface, very low excursion, lightning fast and stiff ceramic membranes, and very linear in the mid bass. and with the dart 458 being 550 watts into 8ohms and 800 watts into 4 ohms with such an easy load you have an ease and explosiveness in the mid bass that is amazing.
those other references of Ron's do not have the mid bass air moving capacity of the MM7's in exactly that 70hz to 250hz range.....and they are all tougher loads so amplifier performance in that frequency range is theoretically less ideal.
again; there are no absolutes. and Ron's opinion as well as yours, and mine too are just opinions and subjective perspectives. I get that the apogee has set your clear reference. references get re-set sometimes. mine, yours and Ron's. so my mind is open to hearing the Apogee's better the MM7's.....or not.
but on paper the MM7's likely can do the same job in it's own way. please visit and listen.