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Quad ESL-57 One Thing
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The One Thing Audio ESL57s have a rather saddle-shaped response, meaning that they peak in output towards both the top and bottom end of the frequency range. This means that they will have a tendency towards brightness but should also mean that they give very good upper mid and high frequency detail, along with good atmospherics.


Down the bottom end, the Quads roll off quite sharply below 60Hz, but peak up in output prior to this at around 80-90Hz. Consequently, they should have quite good low end punch and detail but will not dig all that low, compared to conventional box loudspeakers.


Electrically, the Quads measure like little else, with a single peak in impedance at 100Hz, rolling down both above and below this. Average measured impedance was 10.5 Ohms, but this dipped as low as 5 Ohms at LF and 3 Ohms at HF, so the One Thing Audio ESL57s do need some current from a suitable 4 Ohm amplifier tap. Sensitivity was average at 85dB. AS


FREQUENCY RESPONSE (what it means)



IMPEDANCE (what it means)



Comments (5)
Quad ELS 57
5Friday, 28 November 2014 17:40
Misha Norland
I have owned and loved these speakers since 1965. Recently serviced by One Thing Audio they have new life! There really is nothing to touch them, for installed in the right situation and driven by a good front end, the sound and staging is amazingly clear and shockingly life-like.
4Friday, 31 October 2014 14:29
carl hebb
Wish I had kept my late 57s. Years later I have not forgotten how wonderful they were, despite critical listening position. I have rebuilt 63s tucked away in a bedroom and stored that come out from time to time but they are just not the same. Carl.
One Thing Audio Quad 57's
3Monday, 02 June 2014 19:26
I don't think they are bright just new, a new pair of Quad 57 from Quad if you could still get them may sound bright due to being up to spec.
Quads not normally bright
2Monday, 09 December 2013 20:04
It sounds like they've modified the Quads and changed their warm character.

They haven't returned them to factory specs.

I agree with Manolis that original Quads aren't bright.

The One Thing Quad is a different animal.

Yes, the One Thing has a brighter balance, or you could say it is less warm. NK
ESL 57s rool!
1Monday, 07 November 2011 19:47
Manolis Kroussaniotakis
Thanks to your magazine, I got a used pair over 10 years ago, and listen only to LPs through a Rock II, EAR834P (again, your recommendation back then) and a Quad 405-II. Wow!

They will not be at the level of these reviewed here, but you know, wow! I had the panels replaced by Quad, Germany and also fitted a clamp.

It might be my ears/room but I do not hear them as bright, and I find tuneful bass that vibrates things my Castle Pembroke's could never. I listen to Heavy Rock and Blues mostly.

Now, I would like to hear them with a decent valve amp, but out here in Cyprus, options are kinda limited. And then there's that budget issue.

Like, wow! And you know, the space issue is very real, but consider this- all other speakers are "good enough" but none match these, life is too short, so get yourself a rectangular room, call it a "studio" (photos for me, art or music for you) and let the rest of the world and your nagging other half just, well, nag. They are that worth it :)

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