Thiel Owners

@unsound. Richard Vandersteen and Jim Thiel believed the ONLY thing that can make multi driver speakers time and phase coherent IS a first order crossover. Nothing more nothing less. That assumes the drivers are capable of taking advantage of the first order crossover and its more difficult slopes.

(1) YES there are two drivers in ADDITION to the ribbon tweeter in a 20.7...so, NO there is NOT one "panel/driver" in a 20.7. Maybe the confusion arises because you have two drivers in a single panel in the 20.7 and just about all the Magnepans...and in the higher tiers they blend a long narrow ribbon tweeter into the panels. Its a three-way speaker inclusive of the ribbon tweeter.

(2) YES these speakers do produce a perfect square wave because the crossover IN THE SPEAKER is first order and time and phase coherent. Unlike the earlier 3 series speakers there is no external crossover, rather its now built into the body of the .7 series speakers.

(3) YES my reference to a "crossover" was to the EXTERNAL VANDERSTEEN crossover for the transition from the 20.7s to the Vandersteen subs.

(3) YES the external Vandersteen crossover is ALSO first order.

(4) YES I did prefer the sound of the 20.7’s by themselves to that of the sound produced by the 20.7s, the vandersteen crossover, and the vandersteen subs as I stated above. The Maggies were crossed over at 100 hz to the Vandy subs (pretty high if you ask me). Still, I expected more from the combination thinking that this would be a very clean way to integrate subs into the Maggies but what I found was that on the 20.7 (and I guess on the 30.7 with the extra bass panel per side), the bass is far superior than what Maggies used to be able to achieve in the past. It was clean and coherent and DEEP. The Vandy subs just smeared not only the deep bass but the upper bass as well. I really expected more. But the 20.7 is truly a great speaker I would say especially for classical music. Truly extraordinary I think.

I also have since bought a pair of 20.7s (!). I liked em that much.

@Pwhinson, a first order cross-over might be the only cross-over capable of time and phase coherence. The single driver Quad ESL 63’s and the quasi-multi driver Ohm Walsh, etc.,  did it without an electrical cross-over. Even with a first order cross-over a multi driver loudspeaker will need physically staggered drivers, and as you pointed out wide bandwidth drivers, that will in all probablility need compensating components added to the first order cross-overs to behave as as a time and phase coherent loudspeaker system.

pwhinson
Nice! score on the 20.7 loudspeakers. Between these new speakers and your CS 2.4 speakers, you will have the best of both worlds.  Happy Listening!

Thanks!  I am excited about the Magnepans.  I'm not giving up my Thiels though!  These are in a different league than the Magnepans of the past in terms of coherence and bass delivery.  I heard deep real bass and an apparently seamless frequency range so they've improved that ribbon tweeter, or the crossover.  Or both.  I should have them in a few days and will report back.  I had some small Magnepans about 30 years ago and outside of small ensemble / chamber music they weren't very worthwhile.  These are in another class all together.  

The long-term mutually productive relationship between Thiel and Magnepan may be of interest here. We shared a large majority of our dealers. Dave Gordon came from Magnepan to be Thiel's national sales manager for a decade or more, when he returned there. Both products were well driven by the same source chains. But their presentation was fundamentally different. A Thiel speaker acts as a point source, reproducing what the microphone heard (if we ignore all chain anomalies.) A Magnepan acts as a large dipole, creating its signature sound field in the playback room (augmenting what the microphone heard.) The two approaches aren't really competitive, they are thoroughly different. It is not uncommon for listeners to have two systems, one built around each type of speaker. 

One of Thiel's first reviews was from Scott Estes writing for "The Sensible Sound", who was and remained a committed Magnepan user. He appreciated in print the Thiel presentation, but he wasn't tempted to trade in his Maggies. Hello Scott, if you're out there.