lejonklou wrote:ThomasOK wrote:The first clip is the JBLs and JBL sub as they are normally in my system. The second clip is a different pair of speakers but not Isobariks. They are something else I am trying out. They are a revolutionary speaker designed by a brilliant man with the goal of overcoming many of the problems of normal drivers in a box. They are really quite the speaker and are looking likely to become my next speaker and quite possibly my last one. They are known as the Quad Electrostatic Speaker! (Note SJ and SQ.)
Huh!
I haven't heard Quad ESL 57 in many years, but I remember it sounding rather sweet. I have however more recently installed and listened to the latest top-of-the-line Quad electrostatic. I felt it was excellent, perhaps unsurpassed, on micro dynamics, but lacks macro dynamics. With that I mean that all the small details seem to be highlighted and very faithfully reproduced, while all the louder passages are held back and coloured in a rather unconvincing way.
Not that I have any intimate knowledge, but I wouldn't be surprised if the original ESL is in fact the most homogenous and musical of all electrostatics. It lacks deep bass and can't play very loud, right? And it's easy to break and hard to repair. Perhaps those limitations are what they tried to fix with their later models, but then lost the musical qualities of the original?
As part answer to your question I am quoting a summation about the Quad ESL written by one of the rebuilders. I am doing so because it is one of the best descriptions I have seen.
"The Quad ESL (Electrostatic Loudspeaker) was introduced in 1956. It was a truly amazing speaker for the time, and is still a product to be reckoned with today. Dubbed "Walkers Wonder" after Peter Walker, head of Quad and designer. Many people, myself included, believe that it is the one of the most faithful and natural midrange transducer ever made. At the frequency extremes, it also holds up well, the treble is never spitty or tizzy. The bass is fast and clean without ever being boomy, it only goes down to about 40 Hz, so the bottom octave is missing. Production of the original ESL stopped in 1981 shortly after the introduction of the newer ESL63. Over the 25 year production run, approximately 60,000 speakers were made.
But the original Quad ESLs also have some downsides. First, they are fragile. They need about 15 Watts of the best amplification you can get your hands on. If you use a larger amplifier or try to overdrive the speakers, you risk arcing. Arcing occurs when the potential across the stator panels is sufficient to ionize the air and spark across the gap and through the membrane. Arcing will ruin the panels, if it occurs enough times or is severe. The Quads will play up to about 100 dB, which is much louder than I play music even when playing loudly. The second downside is that they are a difficult load for the amplifier to drive. They are highly reactive loads (primarily capacitive). Their impedance drops as the frequency increases. This makes the Quad ESL a bad choice for single ended tube (SET) amplifiers.
The Quads have a very directional radiation pattern, so you have to position them carefully for best performance. Lastly, they, like all old British things, are quirky and temperamental. Living with a set of Quads is like living with an MG. You will have to do work on them from time to time. Like an MG, when working well, they are a true joy to use. Unlike an MG, after a rebuild, Quad ESL's will work well for decades, if not abused."
To break the myths, yes, the ESL can be blown up by too much power. But they are an electrostatic so this happens when too much voltage is fed to them. In the case of the 57s this limit is 33 volts (or 34 depending on who you talk to). Over that you arc the panel, under that and you won't damage them. The Tundra Mono has a maximum output of 26 Volts peak to peak - it will not overdrive the Quads and you can crank it up all you want. Will it ply loud? Well you wouldn't use it to run a disco in a large hall, and I doubt I could make the helicopter at the beginning of Another Brick in the Wall, Part 2 sound like it is about to land in the room. But I do like to play loud and I really like to play some King Crimson and Porcupine Tree loud and one King Crimson song I really like to play loud is Starless from Red. I put that on a week ago and cranked it way up, it was so loud I turned it down 2dB because it was more than I wanted - even though it was still plenty clean. So I'm not worried about loud.
The Quads are hard to drive - yes indeed, a highly capacitive load that drops to under two ohms at some frequencies. This is enough to blow up amplifiers that aren't very stable and has been known to do so in the past. But good amps the likes of units from Linn and Naim, for example have no problem and Fredrik's amps are extremely stable. So no problem there. I said the TM 2.2s might be the ideal amp for these - completely stable, able to give them as much power as they can use yet unable to overdrive them and the best sounding amps I have ever heard - what could be better?
The Quads have no highs - just plain false. They do have useable output to 20kHz and are a bit more extended than the JBLs. What they don't have is any brightness or sibilance, just a smooth, pure high range. What they also have is very limited horizontal dispersion. So you won't hear the full extension unless you are right on axis. And I do mean RIGHT on axis. They do still sound lovely elsewhere in the room but if you want the full extension you need to be in the center - they are speaker size headphones!
The Quads don't have any bass - also false. They don't go below 40Hz, pretty much just like the JBLs, but they also have absolutely no bloat so they only play bass when there is bass in the recording. They also play it with a level of tonality and deftness that is very rare.
The ELS 63s were intended to play louder, be more robust and handle more power as bigger amps were becoming more popular in the late 70s and they were released in 1981. But they are also completely different. They use a main panel with 7 annular rings that are driven so as to make the sound ripple out from the center to behave as if there is a point source a couple feet behind the speaker. The whole idea of the point source is a great idea and makes for much wider dispersion. It is also a one way speaker, also a good idea and it has additional bass panels above and below the main panel to extend the lows and handle more power. But in order to do this it has to use some very complex display lines to drive the rings at different times. I haven't been able to find the truth about these lines out but I have read thet they may contain 12 to 14 KM of wire! They might not but otherwise they still have to use a lot of wire in the six coils for front and another six for the back to make the inductance to create the delays.
I have never been impressed by the musicality of the ESL 63 or any of the newer QUAD ESL models, all the way through the present ones, which use the same delay system as the 63s just with upgrades to structural rigidity and electronics (and in the case of the bigger models, two additional bass panels). To me they remove some of the "listen through to the musicians" quality that I hear on the original ESL. I believe they are the victims of their own cleverness and complexity. In terms of electrostatics the original Quad ESL seems to still reign supreme. It should be an interesting trip!
