SVS Summer Deal Days is here! Record-breaking savings on acclaimed speakers and subwoofers this week only.
Logo Close Icon

Begin typing your search above and press return to search. Press Esc to cancel.

JansZen zA2.1 Loudspeaker

JansZen zA2.1 Loudspeaker

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.

The division of the mid/tweeter unit is vertical so that beaminess is diminished horizontally but remains extreme in the vertical direction. In effect one has a 16-inch tweeter! You need to aim the JansZens directly at you in the vertical sense—you need to be in that 16-inch beam of highs and preferably in the middle of it. The speakers are tilted back on their pedestals so as to put the axis aimed at ordinary listening height for a listener at three meters. If you want to sit closer, you need to tilt the speakers back farther—or sit very low. This tilting is not hard to do (there are adjustable feet or, for preliminary purposes, you can put, say, paperback books under the front feet).

Already you are beginning to see the adjustability of things. The vertical position and to a lesser but nontrivial extent, the horizontal angling (toe-in) will change the sound. (Actually the vertical positioning is not really an adjustment—you need to be on axis vertically. But horizontally one can control the top octave by toe-in.) But there is much more to adjust. The speakers include level controls on both woofer and midrange/tweeter units.

These adjust the woofer level conventionally, but adjust the mid/tweeter level by changing the polarizing voltage. This means that increases happen fast for the mid/tweeter, but decreases happen very slowly since the higher polarizing voltage has to droop down to the desired lower level. Start at the bottom and push up slowly. And if you overshoot—be prepared to wait a while. (Turning off the speaker is a good way to “reboot” to the lower level but you still have to wait bit.)

We are not through, however, with adjustments, not even if we add in the obvious influence on the bass, which happens for all speakers, of where the speakers are placed in the room. With the airLayer option, which I recommend, there are side-firing tweeters of a non-electrostatic type, ring radiators actually, on the outside sides of the speakers, the level of which can be adjusted from zero to rather strong output.

I have to admit that my initial reaction was to ignore these on theoretical grounds. I like to tell myself that I like anechoic stereo and that it is never a good thing to bounce sound off the walls when one can avoid it. Fair enough—with dipole radiators where one can all but eliminate the first sidewall reflections essentially completely by angling the speakers correctly. Not everyone likes the result, but it is uncolored in energy response.

But with a forward radiator, things can change. Without the airLayer tweeters activated, the first wall reflection has a rapid slope downwards starting at about 1kHz. By 2kHz or so, the energy content has really dropped off a lot and the result is a slightly muffled sound unless you are quite close to the speakers. How prominent this effect will be depends on how close you are to the sidewalls. In the setup I was using, with the speakers only two or three feet from the sidewalls, the sound was improved by activating the airLayer side-firing tweeters—but not too much. In fact, just a touch—activate them too much and the sound gets toppy. But that little touch matters!

This is something one needs to do by ear. And note that there is no big problem—and even, in fact, an advantage—if there is a shortage of extreme highs in the reflected sound. It would probably be ideal to damp the sidewalls quite a bit in the real top and turn up the side tweeters a little further to get extra energy down towards the presence range.

And I found it advantageous to put the JansZens a definite distance from the sidewalls, neither more nor less. This specificity has to do with the fact that since the far-off-axis response rolls off quite a lot starting a little above 1kHz, the exact perceived balance depends on the wall proximity. Another adjustment—but you can get it right!

Truth to tell, I would have liked to see the side-firers themselves rolled down in the extreme top so that one could bring up a bit the energy in the presence range without the top end coming on stronger. But there is limit to how many adjustments there can be. As is, there are many things to try.

Perhaps this all sounds a bit like techno-babble. And the details will vary with the acoustics of your listening room. But you will be able to check for yourself how much effect arises from the side-firing tweeters and from changing distance to sidewalls. Adjust everything carefully! And do go for the airLayer option, I would suggest, but use it subtly.

The Sound and the Adjustments

At this point, a feeling might arise that with so many adjustments, exactly what the JansZens sound like is a moving target. How much simpler are those basically conventional dynamic driver floorstanders, which for all their exotic drivers and extremist cabinet construction are basically, with no disrespect intended, rather conventional speakers perfected, even if they cost a fortune. And, of course, those speakers are simpler in use because they are also unchangeable. If you do not like the sound, there is nothing to do except change speakers, short of changing the acoustics of your listening room and/or using equalization whether digital or analog. (A little adjustment of top end by angling is also usually possible but to a limited extent with almost all speakers.)

With the JansZens, there is more wiggle room, as it were. Now this means there is also more possibility of messing up—you can make the speakers sound really awful if you do the wrong things, say turn the woofers all the way down, the mid/tweeter electrostatic units all the way, and set the side-firing tweeters at max. You ought to try the extremes of the adjustments, just to get a feel for how much control you have—but you won’t want to try the extremes for long.

But if there is opportunity to be wrong, there is also opportunity to perfect, to find, somewhere in the middle, a sound that is all but ideal.

The whole process of adjustment of the JansZens when done right produces something exceptional. And of course once the setup is done, then further experimentation is not needed. This can be a one-time-only process, and although a bit long, an interesting one.

Let me turn now to the specifics of how the JansZens can sound at their best.

The Sound in Musical Terms

First of all perhaps one is struck by their remarkable coherence. Crossovers and driver changes are mostly likely to come across as incoherent in the range above around 1kHz. (This is why three-way dynamic speakers can get away with crossovers around 500Hz, even though that is squarely in the region of music instrument and human voice fundamentals.) Here there effectively is no crossover in the strong sense above 500Hz—the transition from full radiation of the whole of the electrostatic to high frequencies, to only part of the electrostatic panel is not audible.

If one listens to say the piano figures running up and down the keyboard in the first movement of the G Major Grieg Violin Sonata on the Hancock-engineered recording on Bridge, the piano sounds completely unified—the only shifts of timbre are those of the instrument itself. Lots of speakers make it hard to “hear out” drivers, or even impossible to do so. Few indeed give this unified representation of timbre from top on down.

Attached to this is a very low level of perceived coloration. To get everything adjusted perfectly in my room actually involved for absolute perfection a little lift around 1kHz and a little cut around 2kHz, but one could skip this without too much difference. (I am always tweaking around with such things, even though I know few other people worry about them.) And even with the speakers adjusted only on their own, the feeling of neutrality in the true sense was very strong. Not only were the speakers balanced, with the right adjustments, in a natural and accurate way, but colorations localized in frequency ranges were minimal. The JansZens sounded really uncolored.

And as one expects from electrostatics, perceived distortion was extraordinarily low. The speakers added no edge nor harshness nor hardness nor any of the ills that speakers are heir to. With pure-sounding source material, pure sound was what one got. And presentation of detail was excellent. Without anything being flung at you from frequency response irregularities, subtle inner parts (e.g., the harpsichord continuo in the Bach/Sitkovetsky Goldberg Variations on Nonesuch) could be followed with ease but with no sense that they were being over-emphasized. Always one could follow inner parts in complex music with extraordinary ease. People like to quote the lowness of distortion of electrostatics in terms of low harmonic distortion, but my guess is that it is really the low intermodulation distortion over the whole operating range that gives this extraordinary clarity.

And this matters musically. One of the most striking things about live music’s sound is how separated its strands are even when at the same time the overall sound is blended. It is like a tapestry where each thread is visible but at the same time the whole design is completely integrated. This effect is provided better by the JansZens than by almost any other speaker. Moreover, this effect continues when music gets loud. Complex passages remain clear and clean even at loud moments.

Part of this is that the speaker does not put a lot of high-frequency energy into the room. “Room roar,” as I call all that irrelevant sound bouncing around, is minimal. And thus a major source of auditory confusion is removed. The big moment in the third movement of the Mahler Fourth Symphony with Cleveland/Dohnanyi on London, a moment where one instinctively expects to cringe a bit from the confused, ugly sound contributed by the listening room and the speaker both, sailed right by without anything but the powerful effect that this makes in live performance. No cringe at all.

The JansZens are small speakers by the standards of nearly full-range floorstanders. But they have a lot of volume capability and nearly full bass extension. The latter is bit surprising perhaps. But like the Acoustic Research speakers of yore, they use the slow roll off of sealed-box loading and a certain willingness to reduce sensitivity to get really deep bass. (The nominal sensitivity is 87dB—not super-low but on the low side by contemporary standards. But amplifier power is cheap!) Certainly with orchestral music, there is no sense at all of any missing bass. The bass is solid and precise and defined all the way to the bottom of the orchestra— and with one woofer on the floor nearly, no floor dip. Subwoofers are needed only for aficionados of earthquakes or pipe organs of the Romantic style.

Tonal Balance and Stereo Imaging

As noted, the balance overall of the JansZens is both adjustable and position-dependent. When everything is just so, they sound very flat and neutral. To my ears, there was a certain sense of recession of the mids, of the octave from 1–2kHz, although this was a rather small effect. But there is a major difference between the sound of the JansZens and of wide-dispersion speakers, a difference that arises from the nature of the room sound. The JansZens put less high-frequency energy into the room as a whole. And this makes a difference. To some extent, one can offset this with the side-firing tweeters. But not exactly. Namely, the effect of

the side-firing tweeters does not seem to give precisely what would be the effect of a usual wide-dispersion floorstander, where the far-off-axis sound would be rolling down with rising frequency in a pattern designed to give a certain kind of perceived sound balance. This exact idea of speaker balance for wide-dispersion floorstanders is not really based on much (the “science” behind it is really just market research). Some kind of rising directivity with increasing frequency is reasonable but the specification in detail is up for grabs. But one particular pattern is common enough that people are used to it.

The JansZens take a different path from most speakers. As in a concert hall, the reverberant sound in the room is short on high frequencies. They roll off more steeply and sooner off-axis than usual narrow-front floorstanders and thus they have much less energy in the top end in the reverberant field than usual, more like a concert hall. (The comparison with concert halls is not absolutely precise because home listening rooms with their decay that is much faster than concert venues are not really correctly modeled in listening terms as reverberant fields in the sense of concert halls. But for what it is worth, you can find details of the concert hall situation in my article from Issue 38 reprinted here ( Reality.html).

Moreover, the deliberate suppression of early reflections especially in the higher frequencies by the JansZens makes their stereo presentation rather different from the speakers that bounce lots of high-frequency sound off the sidewalls. To my ears, this is to the good. The best stereo available in terms of insight into the recording is from RFZ (reflection-free-zone) rooms, where there are no early reflections at all but there is room sound later. (Truly anechoic stereo, where the direct arrival is all there sounds rather odd and tends to image in the head. This does not happen with the JansZens nor with RFZ rooms since there is enough room sound later to dissipate any possible in-the-head effect.) One does have to admit, however, that reflection-free stereo sounds different, with “spaciousness” generated only to the extent that it rises in the lower frequencies and none of the artificial space and “air” arising from lots of early sidewall reflection in the high frequencies (one thinks of the sound of Bose, perhaps). But the space that is really there on the recordings is presented superbly by the JansZens, with the venue and the microphone technique presented clearly.

This controversy has been going on for a long time and will no doubt continue: How much contribution from the room do you want in stereo playback? As with most controversies, self-styled “experts” abound, promising to have determined the answer. But the experts do not agree, and in the end there is of course no answer that is definitive because there is no real paradigm of stereo recording and playback reciprocity (except Blumlein, where the paradigm is in fact anechoic playback). You have to listen and decide for yourself. But listen on the JansZens to some complex material and observe how clarity is maintained and you will see what can be done with the reflection-free method.

The effect can be truly startling. One can hear something so like concert reality as to be almost mind-boggling. Stereo is by nature a somewhat imperfect process, but it is capable of remarkable things when one removes the effects of early reflections. Be prepared though: This is a different kind of sound from what you get out of speakers with wide dispersion in the high frequencies close to reflective walls. Different and I would say better. But different for sure.


The JansZens will play loudly (well over 100dB) and cleanly at high volumes. These are not dynamically limited speakers as far as sensible use in rooms of domestic size. And they are very linear in dynamic behavior. But their perceived dynamic behavior is unusual precisely because there is no rising “cringe factor” as levels go up. Distortion does not become an issue nor does “room roar.” So one can easily overlook how loudly they are playing. The owner’s manual quite rightly points this out and cautions the listener. I recommend an SPL meter to check occasionally what is happening.

This whole subject is widely misunderstood in audio. One of the mechanisms by which music gives the impression of getting louder is that the distortion produced by instruments themselves increases as they are played louder. An unthinking listener can confuse messenger and message and can start to believe that components with distortion that remains low as levels rise are “undynamic.” I am not making this up. A well-known reviewer claimed for example that the Sunfire Signature (which could put out 2500 watt pulses) was undynamic compared to tube amplifiers. You can form your own impression of what was going on there.

In this same sense, some people who do not know anything might say that the JansZens were undynamic. And then are those people who interpret “room roar” as dynamic enhancement. They must find the front row center in an orchestral concert really unexciting since it is a long time, indeed, before any sidewall reflections arrive. It really ought not be necessary to discuss such nonsense, but these misguided views are expressed so widely that I thought I had better.

In any case, the JansZens remain untroubled when things get loud. This is delightful—and of course correct. But do watch the playback levels. Live orchestral levels—low 90dBs at big moments in front row seats—sound unstrained. And that is plenty loud enough.

I really liked this feature of the speakers—like live music. I am rehearsing the Sibelius Second Symphony at the moment with a 90-person orchestra—loud at times. (I am at a safe distance—outside, first violins—so I do not need ear plugs. It is good to be able to hear realistic levels without strain when you want to, though in practice I almost always listen considerably below the level one encounters at the front of the stage.) And don’t let anyone tell you that the JansZens are undynamic because distortion does not rise with level.

The Big Picture

In the last decade or so, high-end speaker design has to my mind become rather conventional, a matter of perfecting the usual dynamic driver floorstander, where quite standard designs are executed with extreme attention to practical things like cabinet rigidity. But surely the exceptions to this, those designs that to try to go beyond, to find a different and perhaps higher truth, surely those are of the essence of serious audio and are the source of much of its fascination. For those who thus look beyond, who search beyond the horizon, the JansZen zA2.1s are a must-audition.


Product type: Floor-standing hybrid electrostatic loudspeaker
Driver configuration (per channel): Two 7″ alloy cone woofers in a sealed enclosure above and below a 7″ wide x 16″ high mid/ tweeter assembly, comprising two electrostatic panels in separate enclosure internally; airLayer option: One tweeter on outboard side of each cabinet, level-adjustable
Crossovers: First-order 500Hz to mid/tweeter assemblies, secondary firstorder crossover to half the electrostatic elements’ width to widen horizontal dispersion of the high frequencies
Frequency response: 30Hz–30kHz, +/-3dB (in room)
Sensitivity: 87dB /1W/1m
Impedance: 6 ohms nominal
Power handling: 25–150W recommended, 250W maximum
Maximum SPL: 108dB/pair at 4m, room of moderate size
Dimensions: 12″ x 38″ x 14″
Price: $7495 factory-direct, 30-day return option; airLayer option, $495 additional (note: price increase to $8750 scheduled as of Jan 1, 2014)

JansZen Electrostatic Speakers
480 Trade Road
Columbus, Ohio 43204
(866) 535-8835 (North America)
(614) 448-1811 (International)

Robert E. Greene

By Robert E. Greene

More articles from this editor

Adblocker Detected

"Neque porro quisquam est qui dolorem ipsum quia dolor sit amet, consectetur, adipisci velit..."

"There is no one who loves pain itself, who seeks after it and wants to have it, simply because it is pain..."