More questions
Dan,
You are very good at spotting gaps in the information on our web site!
Room compensation adjustment: Not really heavily tested. It's a technical item for helping to deal with wall material absorption characteristics. It happens also to provide what some will find is a pleasing set of high frequency response choices in any room. The effect might also be seen as matching to some extent the effect of audience absorption at a live event -- never does one get a flat frequency response from any position in a live audience other than the first few rows, but recordings are usually made with the microphones placed so that they will receive full spectrum sound. One thing about ESL's is that their natural output rises with frequency, so creating a flat response is one of the basic challenges. Creating a toned down but not dull or notably phase skewed high frequency response is tricky. Anyway, our control does this.
Dealers: This is a complete JansZen restart with me at the helm, after a couple of decades with no JansZen company around, and several decades with no Janszen family member involved. Been building this JansZen Loudspeaker Company for about 4 years so far. Since my father's original JansZen Laboratory in the 1950's became a split acquisition between Neshaminy Electronics and KLH, the JansZen brands you may be familiar with were relatively independent licensees, but yes, a dealer network was always used by those companies.
The San Francisco Bay area has our first dealer. Everyone is encouraged to check with your own favorite dealers about auditioning our speakers, and hearing for yourself what we can only write about here. (Thanks.) They and you may be interested to know that more models are on the way.
Amplifiers: An ESL's load characteristics vary with frequency, so it is not possible to say voltage, current, or power is the main, overall requirement. With ESL's, voltage is important at all frequencies. Voltage is what creates the electrostatic field that creates the force that moves the membrane, whereas with electrodynamic speakers, current creates the magnetic field that creates the force that moves the cone or other shape of piston. An ESL load is capacitive through most of the spectrum, which means that the impedance is usually pretty high, but at high frequencies, the load impedance drops, requiring more power, i.e., the voltage has to be able to push more current in and out of the capacitance. At very high frequencies, resistive loading dominates, but current is still needed for this as well. A capacitive load can create a challenge for amplifiers that run with low phase margin in their feedback loops, but in JansZen speakers, the capacitance is relatively low. One sign of this is that the lowest impedance that an amplifier will see from our speakers is about 4 Ohms at 20 kHz, rather better than the 1 Ohm or less that some ESL's will present, meaning that all kinds of amplifiers with sufficient power can do the job -- nothing special required in that department. At low frequencies, whether the speaker is a hybrid like ours, or a full range ESL, one way or another, either by way of the voice coil or the step-up magnetics, a combination of inductance and resistance dominates the impedance at low frequencies, creating a relatively low impedance for the bass that requires power to drive.
Stereo image: Thanks for mentioning this one! Our speakers have none of the same issues as ML's. For one thing, although you can't see through our speakers, the lack of rear radiation has quite a few sonic advantages. Not everyone will agree. Some instead feel that realism is increased by a large area dipole's greater addition of room ambience to the recorded ambience, although probably not by the peaks and dips from comb filtering caused by interference of the rear wave with itself and with the front wave, or the image smearing from widely spaced arrival times for relatively high amplitude rear reflections, or the lack of damping of the membrane motion that comes with using a see-through radiator, and which can tack resonant tails onto transients that obscure their true nature. This note addresses just a few of the aspects that set JansZen speakers apart and let them reproduce sound more naturally and realistically than other speakers.
Just as a little technical note on sound fields: A cylindrical sound field is created by a line source. A spherical field is created by a point source. Speakers of each type are approximations, but close enough. Lines create a field with intensity that drops in proportion to the distance, ie., 3 dB per doubling, 6 dB per quadrupling in distance. Point source intensity drops in proportion to the square of the distance, i.e., 6 dB per doubling, 12 dB per quadrupling. If you move away from a point source, from 1m to 3m, the level drops by a factor of 9, whereas it only drops by a factor of 3 from a line source. This is why, when one is listening from a position far off the midline of a pair of line sources, the sound from the more distant one is still loud enough to maintain a stereo image.
Resticting myself to ESL's alone: ML speakers can be considered synthetic line sources with cylindrical radiation, achieved by physically curving the source. Sound lab does something similar, with a number of flat panels arranged as facets around a curve. Quad speakers are synthetic point sources, achieved by electronic delays introduced to ring radiators arranged concentrically around a central circular radiator. Coincidentally, the delay lines roll off the high frequencies to successive rings in a way that creates a flat response from the rather large area. Sanders' speakers are close to being true plane sources, which create a field that does not drop off at all with distance, except for dissipation by the air itself. One might consider the extreme directivity of this arrangement a drawback, which plays full spectrum only along the midline and at the distance where the speakers are aimed, i.e., at a single seat, but I must say that the effect is quite amazing when listening in that seat. Ours are true lines, achieved the old fashioned way, by simply using flat sources whose widths are tailored to create the desired dispersion within their frequency ranges. This has advantages in terms of smoothness of the frequency response, uniformity of the SPL and spectrum across a wide area, and integrity of the membrane shape over time.
Center channel: I think I discussed this one already.
Powered version: Many encouraged the development of our internally tri-amplified speakers; none was interested in buying it. We think it may have a future in other parts of the World, but feel it is important to find our place first among American audiophiles, who generally prefer to have control over the amplifier choices, and an upgrade path, or at least an experimentation path, in terms of changing amplifiers. Dealers also seem to like the idea of selling amplifiers separately. One even advised that they would consider the powered version as the entry level model, and kidded that we should charge extra for the passive version. Yah, that's funny.
Building in the amplifiers does make it possible for us to optimize everything to our own standards, but these may not coincide with everyone else's standards. Also, try naming an audiophile who trusts a company that has cutting edge speaker expertise to have equal expertise in amplifier design. As it turned out, it was not as impossible as we expected to develop a passive crossover that rivals what can be done at line level with tri-amplification -- as they say, the impossible just takes a little longer -- and there are lots of excellent amplifiers out there. Several other changes were made in the process that ultimately created an exceptional result.
Regardless of the perceived drawbacks, making them powered does eliminate some bulky gear and fat cables, increasing the WAF and the convenience, and gets rid of the need for protection circuitry, somewhat offsetting the cost of the amplifiers. The powered version can be driven directly from a CD player that has a volume control, or even an iPod, eliminating a pile o' stuff, which is good not just because of the aesthetic and space issues, but cuts down on the amount of circuitry in the signal path. Since they take a single ended or balanced signal, they can be driven from a centralized sound system using generic cable without fear of noise pickup.
Used prices: Your guess is as good as mine.
Factory tours: Sorry, no. But until a dedicated listening room is created after moving to a bigger space, sincerely interested people can sometimes arrange to listen in my personal home. The room is not great, not bad, fairly typical. It has nice dimensions, but is untreated and has a 105 Hz hump that I should do something about. I don't use esoteric gear or cables. In other words, it's a pretty fair venue, in that your observations should carry over to other less than perfect rooms, and will understate the sound one would get in better rooms with better gear.
Country of origin: All major components are made in the USA, except for one injection molded part. Oh, and the woofers are foreign made. All the labor is done in the USA. Surely many of the small electronic parts and fasteners, whose origins we do not check, are foreign made, though. Not much of that kind of stuff is made here, anymore, sorry to say. We do not check specifically where our various contractors get their raw materials, such as aluminum plate, but we have been employing local shops that emphasize a made-in-USA philosophy. Lastly, the woods for the exotic veneers are probably not grown in the USA, but the veneer is cut here. I believe the paints and finishes are US made. About green-ness: The use of veneer helps conserve tropical forests. Practically all the materials are recyclable. We can not guarantee that all future models will be made the same way, but we will try.
