Sonist's Randy Bankert was about to grab some lunch when I stopped by his room on the last day of the Show, but he graciously stayed on to explain what was new about the Concerto 4 speaker ($5895/pair). Art Dudley had reviewed the earler Concerto 3 a couple of years back
and described it as coming close "to being the one true, affordable, all-around satisfying choice among the SET-friendly loudspeakers with which I'm familiar." I had found some cabinet resonant problems, however, which Randy had fixed by the time I auditioned the Concerto 3 at the 2010 Axpoina in Jacksonville. The new speaker uses two paper-cone woofers rather than one with the same ribbon tweeter and solid poplar front baffle, and boasts a claimed 97dB sensitivity. This allowed the Concerto 4 to fill the Atlanta room (sensibly treated with Real Traps) with sound with just 5Wpc from the EL84-fitted Glow Audio Amp One ($648). Source was a Cary CAD306 SACD player.