Guttenberg and Quad Electrostatics

@snapsc  That's why I have 2 rigs!

Former quad owner here. Two thoughts... back in their time, there almost nothing like them in their ability to produce open and hauntingly dimensional sound for some types of music...(many speakers do that now). 

And... some days you like chocolate and some days you prefer cherry... same with speakers... nothing wrong with enjoying the quad detail today and Volti dynamics tomorrow. 

As for Steve, I think he says he owns and enjoys at least four speakers not including those he reviews.  

Love 'em. Forget having them on the original feet. I feel they work best like this:
https://systems.audiogon.com/systems/1593

The old Quad can actually reproduce some bass given the large-ish panel size so they work for small jazz combos, any smaller scale stuff; it isn’t what I would play Sabbath on at high db because that isn’t what the speaker’s strength is-- but voice, strings and even orchestra can work, though I found that on large scale works you hear from a more distant perspective-- like sitting in a balcony, not up front. The midrange can be eerie, it’s so "there" on some recordings; like most things in audio, you often don’t realize that you are hearing an artifact of the machinery playing until it is gone and the Quad can disappear.
All that said, they present a weird load to the amplifier, can’t take power or they will arc (not good) and are dynamically limited in how many db they put out. But dynamics is a relative thing. If you get the system to reveal information at lower volume levels, the crescendos or louder parts don’t have to be as loud in an absolute sense to give you the dynamic range of most music.
I used to use ARC tube amps; I currently use a pair of Quad IIs made in 1961 that were refurbished and retubed with first class glass-- NOS GEC KT 66s, which were originally spec’d for the amp.
They are a cool thing to be able to learn to listen through, and hear the music, rather than having it played at you when everything lines up.
When you consider how well these do what they do, you are willing to forgive some of their limitations given that they came to market more than 60 years ago and many are still in use.
I did a piece on what it is like to own and use them which I can post. But, for some, modern speakers will put them to shame in other areas that may be more important overall. For me, the midrange is absolutely critical and that’s where these shine.
PS: I’d add that the bass that is there, when properly positioned, is coherent and tonally correct so you don’t hear discontinuities typical of multi driver speakers. Adding a sub, at least back in the old days, detracted from that sense of "oneness"-- that the entire presentation is one piece--and you were aware that you were listening to different speakers. The Gradient was used with the 63 and I guess with the 57- the older one-- which is the speaker I’m talking about. There are a multitude of other options to enhance bass, including open baffle, Maggie bass panels, adding more Quad panels, etc. but in my estimation, it defeats the simplicity of the thing. I wouldn’t mind a stacked pair if I could squeeze them in, but my main room is already occupied by a big system, and a stacked set of old Quads in my front parlor would overwhelm the room, aesthetically if not sonically.
You should hear them for what they are and aren’t. I don’t think they are the "right" speaker for someone that needs an all around speaker system for all types of music, especially if you listen to hard rock.
The later model- the 63 -- was a better all around speaker as are the later incarnations, but the 63 I had, as modified by Crosby--which was the bee’s knees at the time-- just wasn’t in the same league to my ears as the original for midrange purity, though it is the "better" speaker for overall use.

What I’ve read ( never heard them) is that chamber music is the “ right” material for them and that it’s very difficult to match a sub with them. Is this true?

Dunno. I have a pair of Quads I bought in 73-74 that I had refurbished a couple years ago that run in my second, vintage system. And I switched to horns in my main system from a pair of Crosby modded Quad 63’s back in 2006 when I finally signed up at this forum after using it over the years as a non-participant.
There’s a lot to be said for coherent midrange. Augmenting the horns turned out better than augmenting Quads, at least for me, at the time (I had a mini HQD system running at one time in the ’80s with a pair of Decca ribbons--still got ’em and various subs). Could not match the character of the Quad.
With the horns I’m cheating since I’m using a hybrid to begin w/-- Avantgarde Duos, which use an integrated woofer system to get bass. But they don’t go very low and if you try and get them to play low loud, they mismatch the horns. However, when you dial in the woofers to match the midhorn, and then match the woofers to additional subwoofers (in my case, a pair of 15" sealed cabinet with DSP running only on the subs), you perform what is in essence a sonic magic trick. It works.
As to the cult like reverence for the old Quad, I'm still in. They present an amazing sonic picture within their limits, which are, admittedly, significant. They are worth hearing, and in my estimation, sounded better than the 63. I haven't heard the most recent version of their electrostat but the original remains a classic for a reason. Owners who had them and sold them buy them again. Or, like me, never get rid of them. I stopped using them in 1990 when I bought the Crosby modded 63 and promised myself when I crated them that some day, I would have them restored. They are a great listen, particularly with the "right" material-- not exactly an all arounder. 

Quads sound great. Horns sound great too. There you go.

Experience will effect tastes.