While we are nit-picking an old article, what about the 50 years as a limit? Then the K-horns, originally offered by PWK in 1947, would be off... as well as the AR-1 & 3! We really owe a great debt of gratitude to both PWK & HK for their work. No telling how many AR-4X, cheesy EICO 3070 amps, and Garrard 50/Shure cartridge combo's I sold at Herbert Music in Auburn, AL in 1968 to my fellow Auburn U. students - definite 'baby boomers'. I bought my AR amp and turntable there @ 40% off as an employee - still have the turntable. I joined the USN 2/69 - out in 11/72 - back to AU, finally getting a pair of Large Advents, long gone now after several re-cones. Skip ahead by several decades to my most recent "Advent" replacements: NHT S1 2.1's! My latest find, a marriage of sorts of HK's acoustic suspension LF driver with the PWK K-horn's loaded compression horn MF & HF drivers - a nice pair of 1977-78 Heresys!
Gene, a belated thanks for your spot-on compilation.