Phillips: I suspect we're getting ahead of ourselves. Sanders: True, our first transducer had none of those elements. I built that first speaker right out of a hardware shop: perforated aluminum for the stators, Plexiglas for the spacing elements, epoxy glue to hold everything together. I found some half-mil polyester film somewhere and sprayed insulation onto the stator. To get a conductive coating onto a diaphragm, I burnished graphite onto the film.
Phillips: You just rubbed it into the polyester?
Sanders: That's right. It gives a nice semiconductive surface—you don't…
Phillips: We were just talking about your prototype, which used flat panels. How did you determine that you needed curved panels? Sanders: That's the classic drawing-on-a-napkin-in-a-Chinese-restaurant design story. Ron and I were eating dinner, chit-chatting about speaker design. As we talked, I sketched a waveform moving away from a point-source. It became clear to both of us that the information on-axis was farther away in time than the information coming from the sides—I drew these little points and we literally connected the dots. I looked at the napkin and said, "Ron, could it…
Sidebar 5: Measurements I hate measuring panel speakers. Why? Because the usual assumptions you make when you measure a loudspeaker—that the microphone distance is large compared with the physical size of the speaker and that the mike is therefore in the speaker's farfield—are no longer true. As a result, the interaction between the microphone and the speaker is much more complex than is normally the case. In addition, the measured performance of panel speakers is enigmatic. Compared with a typical moving-coil speaker, the measurements can look worse—yet listeners like the sound more. So…
Moving on to the measured frequency response, this was taken on an axis level with the midpoint of the electrostatic panel, 42" from the floor. Visually smoothing out all the little ripples, the SL3's response appears to shelve down above 1kHz. Remember, however, that there will be an interaction between the speaker and the measured response due to the relatively close microphone distance. There will be a "proximity effect" that raises the speaker's apparent midrange output the closer the microphone is to the speaker. This is graphically shown in fig.3, which shows the on-axis response…
In the time domain, the SL3's step response (fig.5) is beautifully coherent, the rise away from the time axis being almost vertical. Further analysis is difficult, so I have also shown the individual step responses of the panel and woofer (fig.6), plotted to a slightly different scale. The panel can be seen to overshoot the time axis on the return of its step to zero, with its second positive-going move overlaid with the slow rise of the woofer output. There will be some cancellation between the two drivers, meaning that the SL3 owner should experiment with the room placement to get the…
Sidebar 6: Manufacturer's Comment Editor: I know when the team of Wes Phillips and John Atkinson get hold of a speaker the manufacturer is going to learn even more about his product than he knew before the process began. We are Martin-Logan feel that the SL3 represents new levels of audio performance and it feels good "back here in the Midwest, that your observations are close to ours."
A few issues regarding the testing procedures. Yes, our products are different from point source products in the way that they launch information and, as a result, our testing procedures differ…
What is the difference between the near field and the far field? In the far field the dispersion pattern can be described in terms of angles and a constant (1/R) term. Meaning the radiation pattern is independent of the distance. In the near field, this is not the case. The radiation pattern is dependent on the distance.
What the hell does all this mean to us?
What it means is that a person sitting 3' away from the speaker will hear something different than a person sitting 10' away, even if they are at the same angle to the speaker. How then do we get a fair measurement…
Judging absolute sound quality under the unfamiliar circumstances of an audio show is always fraught with difficulty. If a system sounds bad, there are so many possible reasons for it to do so that pointing a finger of blame at the components is possibly unfair. Conversely, when a room sounds good at a show, it is probable that the components being used deserve some recognition. Such was the case at Home Entertainment 2002 in New York last May, when Dynaudio's Confidence C4 made its debut. Driven by a Naim CD player and Naim amplification in a fairly large room, the loudspeaker impressed…
With its narrow, 10"-wide profile, the wood-veneered cabinet looks smaller than it really is, though a 16"-wide base, fitted with spiked feet, provides mechanical stability. The drive-units are carried on a gray sub-baffle sculpted from 40mm-thick MDF, which is attached to the front of the enclosure. Fit'n'finish were superb, as should be the case at this price level. Sound
In my approximately 3100-ft3 room, finding the positions where the Confidence C4s worked optimally was more problematic than it had been with the other speakers I've reviewed recently. In particular, getting a…
Looking through my auditioning notes, I see that I listened to a great deal of choral and vocal music through the Confidence C4s, which bears testament to their uncolored, natural-sounding midrange. The midrange, roughly the decade from 200Hz to 2kHz, is where melody instruments and voices have their fundamental energy and where the music has its tonal center. If a speaker gets the midrange wrong, then what it does right at the frequency extremes to a large extent doesn't really matter. This Dynaudio got the midrange right, to an extent equaled only by the Wilson, Mission, and KEF, of the…
