What Scotty said...
Seriously Ian, it does seem fairly obvious why the Dunlavys should sound more "visceral" and "enveloping" compared to the Europas given the physical differences between the rooms and your speakers. You have the SC-II (not the stand-mounted SC-IIA), right? This would be the floor-standing model that has dual 6.5" woofers and a 1" tweeter mounted in a symmetrical array, on a 5' tall sealed cabinet. For one thing, the SC-II has to pressurize the air within a room that's roughly 1/3 the volume of the room that the Europas are in. On top of this, the fact that the SC-II's sealed cabinet is of much greater volume, in addition to its dual woofers, should mean that it's capable of deeper bass that rolls off more slowly compared to the Europa's bass reflex alignment (12db per octave vs 24db per octave). Given all of the above, it stands to reason that the SC-II should sound considerably more energetic, or "visceral" to borrow your term, not to mention more effortless and spacious. It would be interesting if you can swap the speakers between the two rooms (leave the equipment where it is), and then give it another listen.
John Casler,
I agree with you that John Dunlavy was and is brilliant. However, I think that it's fair to say that there are actually more differences between Dunlavy's design philosophy and Brian Cheney's than there are similarities. What I think sets Dunlavy apart from almost any other manufacturer, past or present is:
-His design methodology, which places primacy on measured accuracy. Blind listening is a critical part of his evaluation process, but it's only done after the accuracy of the speaker has been demonstrated through its measured performance. All of his speakers were required to meet strict design criteria that included frequency response measured to within +/- 1 db of its designed bandwidth and the ability to reproduce a "textbook perfect" square wave as proof of its phase accuracy. A speaker would not leave the factory unless it had the test bench measurements to prove that it met these requirements.
-Use of minimum-phase 1st order crossovers with stepped baffles, which is consistent with his belief that phase coherence and time alignment are inseparable
-JD used highly damped, sealed acoustic suspension cabinets exclusively, in order to preserve phase accuracy (as opposed to a bass reflex alignment w. passive radiator)
-He was *not* a fan of ribbons, preferring instead to use domes and cones that met his impulse response requirements
-Dunlavy pioneered the use of wool felt anti-diffraction material on the speaker's baffle
-Symmetrical driver arrays (e.g. MTM or WMTMW) were featured on almost all of his speakers in order to emulate a point source, and the driver arrays were oriented so that their radiation would converge at a point on the tweeter axis precisely 10 feet in front of the speaker, becase JD believed that far-field listening was what most people preferred. The notable exceptions are the Athena and the Cantata, which had an MTM plus a single downfiring 10" woofer. However, a two woofer version of the Aletha/Athena (one downfiring, the other firing from the top) was also offerred.
While not all of the above are unique to Dunlavy and some other manufacturers have followed similar design goals, none that I'm aware of have successfully duplicated all of what Dunlavy did with the same rigorous attention to detail. In terms of physical similarities between Dunlavy's designs and VMPS, I can think of only the symmetrical driver array (in some cases) and the use of 1st order crossovers. In closing, I say this not to suggest that one person's approach is better than another's, but simply to illustrate that there is evidently a vast difference between the design philosophies of these two men.
