ESL57 vs ESL63

Can’t give you a comparison but the 57s needed a fair bit of SS power. I don’t think my Naim amps ever worked so hard before the Quads arrived.

After reading nothing but praise for them I went to a lot of trouble to get a pair but they didn’t stay long. Sure, with the right recording and the right alignment of the stars they might be capable of stunning vocal reproduction and imagery but...they do need a lot of fuss as well as lots and lots of space.

The final straw broke when I played some Rock through them and received an entirely lacklustre result. One for Classical and Opera fans foremost I think.

@cd318  All ESLs have an impedance curve that varies by about 9 or 10:1 from the bass to about 20KHz. A solid state amp can't make any power into the fairly high bass impedance of the ESL57 (about 45 Ohms IIRC). So many solid state amps sound lackluster on them. Many tube amps though can make power into this impedance and so will be a bit more exciting.

The old Quads, being ESLs, are not based on the idea of being 'voltage driven'. Keep in mind when the ESL57 was designed - the 1950s- and amps that could act as voltage sources were not all that common. For more on this see:http://www.atma-sphere.com/Resources/Paradigms_in_Amplifier_Design.php
Since the Quad's impedance curve is not based on a dynamic driver in a box with the associated resonance, its impedance curve (which is based on capacitance) is not **also** a map of its efficiency. In order for it to play at 90dB at 100 Hz, it needs the same power to do that as it does at 1000Hz, and the two impedances are quite different at those frequencies! So an amplifier that can double power as impedance is halved (solid state) won't work. In fact, if a tube amp has too much feedback (output impedance is too low) that also won't work. But there are many tube amps that do work. We've got a lot of Quad customers and one of my employees owned a set as well as several friends of mine in town. So I've heard them a lot with our gear.


The speakers do need some power (the ESL63 needs more than the '57; 100 watts is about perfect but 60 watts does nicely). So SETs are right out unless you have a small room which usually doesn't work, because you really should have at least 5 feet to the wall behind them. Otherwise you can get a one-note bass. BTW this tends to be common with people that have solid state amps- because transistors can't make the power into the bass regions of either speaker, they tend to be too close to the wall behind them as this does reinforce the bass a bit, but only at one frequency.


There are certain speakers that we've seen over the years that have an above normal loyalty with their owners. Quads are on this short list. By this I mean they just don't sell them, even if they aren't using them- they 'come back' to the Quads again and again. They are a very good set of compromises- they are not too hard to drive, they play bass well if driven by the right amp, they are very fast and revealing (they are ESLs after all) and if properly set up very satisfying.

@atmasphere , thanks for the explanation. That helps to clear up a few things, albeit decades later.

I can remember being puzzled at having to turn the Naim amp volume dial past 12 o'clock (before getting cold feet recalling the old horror stories of the panels arcing and being left with tiny holes) without any reciprocal increase in sound. 

I appreciate the information, as I'm sure others will too. The previous owner used them valves but neither he or I knew why it might matter (although a good clue might the date of manufacture). They were in great condition and had new panels fitted by Quad so moving them on was no problem.

So I guess I never really got to hear what they could do. "A great set of compromises"?  Maybe some of those reviews weren't so overblown after all.

Oh well, you live and you learn!

It seems that when properly set up and amped there is very little that can compare to the sound of the ESL 57’s - the realism, resolution and liquidity, just seems to be unmatched for all acoustic sounds (e.g. jazz, classical, country, sax, trumpet, violins, cellos, bass, guitars, voice, etc.).  But, I guess you have to be tolerant of their set up requirements, and prefer the kinds of music at which they excel.  Which is why I’m considering the WP ESL 57’s.  

But, are there any dynamic speakers that come close to duplicating their sound quality?

It seems to me, that the Harbeth 30.1 and 40.1 / 40.2, when driven by the right tube amps, come very, very close to duplicating the sound of the 57’s.  

Does anyone else think so? 

Sure, other ESLs. It is just that people do not get to hear them as the big ones take up a lot of space and are domineering. For some reason shops do not like keeping them around. Maybe hard to sell a Magico or Wilson with Soundlabs on the premises. It is hard to miss them and they are a much better value if you can get them by the wife. 57s were amazing loudspeakers 50 years ago for Brits who like classical music. But, technology moves on particularly materials science. There are ESLs made today and in the past that have the sound qualities of the 57 and are not nearly as temperamental.