@clio09, were the speakers on the side wall ESP’s, and the designer’s name Sean McCaughan? I saw and heard them in the 1990’s at Acoustic Image in Studio City, CA, a great high end shop in SoCal. Never got to hear the Beveridge, though I heard the Dayton Wright’s in 1972 or 3 when David Fletcher (designer of the SOTA table and Sumiko MDC 800 "The Arm") had a little retail shop in Berkeley.
Anyone who has heard the original Quad and doesn’t think it is extremely good at reproducing vocals and other acoustic instruments, well, I don’t know what to say. Uncolored, see-through liquid transparency (low energy storage in the near-massless Mylar, which starts and stops on a dime), natural timbres and textures, the ability to make every thread in a densely-woven tapestry or fabric (every voice in a choir, for instance) clearly audible as a separate entity. Other ESL’s, too. All speaker designs have their own strengths and weaknesses; you have to find one that excels at those characteristics in reproduced music you value most, your priorities.