Thanks to all for the responses so far. The comments make good horse sense regarding the listed speakers of a bygone age. I have always been interested in whether some of these early classics of sound, if driven with newer and/or better electronics would provide the ultimate euphoric, or easy listening experience that you don't always find in today's.speakers Yes, greater accuracy without a doubt, but does the listener really feel the music is both engaging and listenable. I owned a pair of Large Advents in 2005 and drove them with an Aragon 4004 MKII; the rest of the system was CJ PV-8 and Sonographe Beta one CD player. There were moments when I said this is one greatest speakers I ever heard. The Advents flourished with 200 watts plus. The problem that during their golden years approx. 1969 to 1985, Advents were driven by 45-50 RMS Marantz, Pioneer, or Harmon Kardon receivers which were just adequate, but not if you wanted to play music loud whether rock or Beethoven.
The Advent tweeter that I mentioned in my :"side note" was a worthless compromise on Kloss's part regardless of the attenuation switch on the back. It looks like hardware store vintage, and sounded like crap..
Member....Akg-ca was on target when he noted the cheap caliber of the parts being used to hit a certain price point. All to often the frequency range of the media available.at the time, (LP's and tape) dictated the quality short cuts taken by Henry Kloss and Dave Hafler.
Another factor, I believe, was often the social setting of the buyers. Young Couples with new homes seemed to be the perfect target for the Large Advent speaker. It is not really a rock speaker and sounds good on jazz folk, most light classical, and easy listening music.
However, old and inadequate these "geezers" might be and sound by today's audiophile standards of musical satisfaction, there seems to be a ton of Advent, Dynaco, AR and KLH, etc speakers being refoamed and retooled out on the market. It might be just nostalgia driven, or just a desire by many listeners to just lay back and listen to the music.