Any better midrange driver than an electostat?

[Steve Williams]

Great post Tom

as always they are most informative

 

[microstrip]

(...) The fly swimming in the beer is the speaker requires a high voltage signal which is supplied by something like a tube output transformer connected backwards.
That is fine, the issue though is that the stators have a capacitance between them and what you are doing with the signal is changing that voltage which being a capacitor resists until you have put current into it.

Reflected back through the transformer, the electrostatic can look pretty different than a ‘normal” speaker to the amplifier, in that is has significant capacitive reactance. (...)

Tom,

It is true in some cases, but can not be seen as rule. I have measured the impedance modulus and phase of several electrostatic speakers, including my big Soundlab A1 px's and ESL63 and found that the phase angle of some electrostatics is much less than the phase of the impedance of some cone loudspeakers. Although the impedance of an electrostatic loudspeaker is different from a dynamic speaker, I think that some other parameters are needed to explain why some amplifiers sound better with electrostatics than others.

 

[Tom Danley]

Hi Steve, hey thanks!

microstrip brought up a couple good cases to look at.

The electrostatic speaker as a transducer is capacitive for the reasons I described and is driven by a direct drive amplifier or step up transformer to get the required signal voltage swing.
Now, the question of where the sound goes comes into play.
For a fixed size, a flat panel ess will have a radiation pattern that narrows as the frequency climbs. If it is producing a fixed power, then this would cause the SPL to rise as a fixed power is focused into a smaller and smaller area.
A first order slope can be applied to correct this by allowing the Rdc of the transformer primary and secondary to form an R/C low pass filter to counter directivity .

Anyway, the fact that the radiator is a “variable acoustic size ”effects the directivity, some speakers like maggies have a tweeter section of a more compatible acoustic size.

The ESL-63 was like no other speaker I had ever seen. My boss at Intersonics in the 90’s had a pair and kept popping the internal spark gaps. He knew I made ESS speakers and so he asked me to “fix” them so they wouldn’t spark, and to be clear in a lovely old English accent he said “tear the bloody things out’.

These were far more expensive than anything I owned and they were my boss’s to boot so I was really careful taking them apart. I got the grill off blinked twice and though WTF is this????
I had built bunch of simple flat and curve electrostatic speakers, this was NOT that at all.
These fought off the narrowing by radiated a portion of a sphere, constructed by sequentially driving a flat diaphragm in rings, rings of electrostatic speaker. See the picture below, see the rings, the signal is presented at the center first, then progressively outward as if an expanding spherical segment of sound passed through it.

http://www.hifiengine.com/manuals/quad/esl-63.shtml

In order to produce this effect each ring is driven separately, each signal is progressively delayed with a “delay line” which is made of capacitors and inductors. In the schematic one can see the delay line is the series of coils and capacitors with the “VA” through “VG” delayed taps. Each pair of L’s and C’s in the line may also be recognized as a 2nd order “all pass” filter, a filter which has flat frequency response but exhibits phase shift.

http://mark.rehorst.com/Quad_ESL-63/Quad ESL-63 Simulation Schematic.png

Anyway after removing the offending “protection” I listened to them but not loudly, for a weekend.
They had a hypnotic effect on me, when someone spoke, it sounded like the speaker was an opening into another space like window or something, not the source of the sound like every direct radiator I ever heard. .
They had no apparent flavor in fact underwhelming at first until I heard subtleties I had not heard before.
They were just a little bass shy for my taste but they disappeared like no speaker I had ever heard at the time or would ever hear for a long time to come.

Anyway, my point before daydreaming there was that unlike the other ESS, those distributed the C’s out with a transmission line, they are not like most.
Fwiw, I don’t know the model but the large Soundlabs I heard were luscious sounding and driven by some large futterman OTL’s, I didn’t want to leave.
Best,
Tom

 

[kach22i]

the sh-50 radiates a portion of a sphere

I looked it up, an interesting speaker design.

 

[mullard88]

Going back to the first post . . . .

I have owned the Acoustat 2 + 2, the Martin Logan Sequels, the Crosby modified Quad 63, and the Stax F 81 electrostatic speakers. I have kept the Crosby modified Quad 63 and the Stax F 81.

The Crosby Quad is the eletrostatic speaker I most often insert into my system. My equally favored amps for the Crosby Quads are the Crosby Spectral DMA 50 monoblocks, the Lamm M1.1 and the Audio Research D 76.

Way back in the 1990s, a company that no longer exist made the Metaphor 2 dynamic speaker. I remember that there were several occasions when these speakers fooled me into thinking that I was listening to the Crosby Quads.

 

[lydon]

Probably not, but Vandersteen 7 comes close

The three driver array handling high, mid-range, and upper bass frequencies on this particular design has been characterized to be so transparent that it rivals most if not all electrostatics. Throw in an 11 band E.Q. & a 400 watt self contained powered bass driver, you've got an exceptional speaker to compete. But @ only 83.5 sensitivity you'll need lots of power to drive them. My listen sessions have been simply outstanding, especially with vinyl.

 

[c1ferrari]

Plasma Driver

as evidenced by Dr. Alan Hill

 

[ack]

Let's not forget a hybrid electrostatic is as fast as its crossover and electronics

 

[henzefan]

caesar​

Well-Known Member​

• Apr 10, 2011
• Add bookmark
• #1

I haven't heard anything that comes close, but I haven't heard everything. IMHO, electrostats rule in producing the most realistic sound, other than the bass.

Anyone make a driver that is close or better?

~~~~~~~~~~~~~~~~~~~~~~

Expebsive high quality horn = beats stats midrange
But another alternative is
the new wide bands
Tang band 2145 and DavidLouis VX8
Both deliever clean, clear, no distortion, no fatigue midrange, FULL /Total Midrange. with authority and yet ease , neutral, natural sounding

 

[Diasoft5]

Accuton diamond midrange

Gauder Akustik - Berlina RC 9 Black Edition

or

Göbel Carbon Excellence bending wave driver

Göbel High End - Ultra High End Speakers and Cables (goebel-highend.de)

 

[Addicted to hifi]

caesar​

Well-Known Member​

• Apr 10, 2011
• Add bookmark
• #1

I haven't heard anything that comes close, but I haven't heard everything. IMHO, electrostats rule in producing the most realistic sound, other than the bass.

Anyone make a driver that is close or better?

~~~~~~~~~~~~~~~~~~~~~~

Expebsive high quality horn = beats stats midrange
But another alternative is
the new wide bands
Tang band 2145 and DavidLouis VX8
Both deliever clean, clear, no distortion, no fatigue midrange, FULL /Total Midrange. with authority and yet ease , neutral, natural sounding

Great clip.

 

[Addicted to hifi]

I like planer midrange drivers better that stat.