I suppose everyone has the dream. After a long day at an audio show, somewhere down that last corridor, suddenly there is a speaker that transcends all that went before, that gives the audio analog of how Sibelius described the inspiration for his Fifth Symphony: “The Gates of Heaven opened and I heard the music.”
Of course such an audio experience is never quite complete, and the impression might be momentary, too. Almost inevitably the critical intellect begins to take a role, and some small or not so small things may begin to disturb. (Sibelius had to get down actually to doing the orchestration, too.) But still, I had an experience along these inspirational lines when I heard the JansZen zA2.1 loudspeaker at the T.H.E. Show Newport this just past July. And this impression has survived the long exposure of the review process largely intact.
The JansZens strike me still, after that long exposure, as having an unusual dose of sonic magic. They are high end in what used to be the traditional sense, in that quite a bit of effort is needed to get the very best out of them, but the very best is very good indeed. And if the article that follows emphasizes the adjustments possible and the need for them, please never lose sight of the fact that at the end of the road is a speaker in the top echelon at re-creating the beauty of concert music. The zA2.1 is a fussy, listener-position-dependent, at first potentially frustrating loudspeaker—not a plop-it-down-and-sit-anywhere speaker that will provide a fairly good but perhaps not great sonic experience in casual use. But with things done right, the magic is there to an extent that few others can offer.
Perhaps one should not be totally surprised—“What’s bred in the bone” and so on. Designer David Janszen’s father Arthur Janszen, was one of the great figures in audio in the 1950s and 1960s—the designer, in particular, of the legendary KLH Model Nine full-range electrostatics, which incidentally were a driving force behind the founding of The Absolute Sound. (In an interview with John W. Cooledge some time ago, Harry Pearson described how a “shoot-out” between the Nines and the then widely celebrated Bose 901s was a pivotal event in the decision of JWC and HP to start TAS together.) But if David Janszen grew up with electrostatics and learned the art of making them in his family setting, he has also surely struck out in his own directions with the zA2.1s (hereafter, just “the JansZens”).
The Speakers Themselves
For a start, the JansZens are not dipoles. Earlier electrostatics— the original Quads, the nearly contemporaneous KLH Nines, the Dayton Wrights, the Acoustats, the Xstatics, the Quad 63s, the SoundLabs, the MartinLogans, the Sanders—operated their electrostatic part at least as a dipole. Outside of some of the Beveridge models it is hard to think of an electrostatic that did not use the electrostatic element in dipole form, except in some cases where the electrostatic part was used purely as a tweeter.
The JansZens, on the other hand, operate the electrostatic element inside an enclosure. The electrostatic element (which is itself compound) covers both midrange and treble frequencies, with the crossover from the cone woofers being at 500Hz, first-order. The two-woofer system is housed in a sealed box, one driver above and one below the mid/tweeter electrostatic unit. And the whole fits together to form a single compact floor-standing unit which does not require placement far out into the room, as dipoles inevitably do if used at any but very high frequencies.
Peter Walker said he once experimented with an electrostatic unit in a box but went back to dipoles because to him it sounded like a speaker in a box. With all due respect, this was apparently not inevitable. To me, the JansZens do not sound boxy at all. And, in fact, the unipolar nature of the mid/tweeter unit likely contributes to the remarkable coherence of the speaker since it matches the nature of the woofer at crossover.
The mid/tweeter unit itself has a crossover, with the whole area operating in the lower part of its range but part of it rolling off in the highs so that only a portion radiates the true high frequencies. This diminishes the otherwise inevitable beaming associated with running a flat radiator that is four inches wide on out into the stratosphere—the response of the JansZens extends to at least 30kHz, according to the designer.