What vintage speaker might you use today

I have no doubt that I will be the first of many to name the obvious first choice, the original Quad ESL.

Sunnyjim---To be aware of the "pre-AMT tweeter and Dr. Heil" era ESS, you are either as old as I or a Hi-Fi historian (or both)! I happen to have such a pair of loudspeakers, the ESS Trans-Static I's. I found them in L.A.'s The Recycler paper in the mid-80's for $400 ($1200/pr retail when new), in good working order except for one woofer being a cheap imitation of the original Kef B139. I called ESS and was told they had one remaining B139 in stock!

The Trans-Static was a pretty advanced loudspeaker when it was introduced (1970, I believe), having three RTR ESL tweeters operated open baffle/dipole, a Kef B110 5" midrange driver loaded into a short (15", the depth of the enclosure) transmission line, and the B139 woofer (which Dave Wilson used in pairs in his WAMM loudspeaker later in the decade) with a long folded-transmission line behind it. X/O frequencies were 275Hz and 1500Hz (designed by a young John Ulrick, cofounder of Infinity Systems, and now owner/designer of Spectron Audio), and each speaker weighed a substantial 139 lbs. They still sound pretty good!

Right Jim, the transmission line loading of the woofers in the ESS "Trans" series speakers made for unusually deep and tight bass for the time. The dome tweeter in the lesser ESS' was okay, but those RTR ESL's in the Trans-Static were SOTA. Fulton used the RTR add-on tweeter assembly (which contained six of the tweeters) in his Model J loudspeaker in '74, another really good one.

The midrange of the Fulton Model J was the FMI 80, mentioned on it's own above by salectric.

As I was composing my post directly above, Doug posted his. Also well reasoned, I second his recommendation to augment the Quad with a pair of subs. But not just any sub---the GR Research/Rythmik OB/Dipole Sub. It is in some ways similar to the one Gradient designed and offered for the Quad ESL63 in the 80's and 90's, but quite a bit better. It is particularly well suited for dipole loudspeakers, sounding very different from a "normal" sub, no matter the quality. You can read all about it on the GR Research website and in their Audiocircle Forum. Very special!

Well said trelja! You (and I, and ct0517) are not alone in finding enduring merit in the original Quad when used within its limitations. Yes, those limitations are severe, making it unsuitable for many applications and listeners, Douglas Schroeder apparently included. But for "small" music (Baroque, Chamber, Vocal, acoustic Jazz Trios/Quartets/Quintets, etc., Bluegrass, Folk, etc.) at modest (though sufficient) volume, the Quad is still not just unbeaten, but, say some, unequalled! A fair number of loudspeaker designers keep a pair of quads around with which to help voice their own designs, and recording engineers still use them to check the naturalness of their work, vocals in particular (ask John Atkinson).