Panzr- and Kloss did all his great work w/ a microphone, oscilloscope & his eyes & eyes. No computers, no real high tech materials, no exotic cabinetry. For folks who never heard heard a properly set up stacked pair, grill cloths removed, w/ a good, powerful amp & good source, you would be surprised just how good they could sound. That was maybe $500 for 4 Advents in 1974 ( walnut cabs) so today maybe $4K? Other than a more extended, open high end, they would compete w/ & beat many offerings today & easily in the bass.
This topic has been covered many times. I owned stacked Advents back in '78-81 and they were driven by HK Citation amps. It is true that they were "a thing" and could put out a lot of tight low-end grunt and a wall of sound. IME, they were not up the SQ of better modern day loudspeakers. I just got done with a workout in my basement (riding to Zwift on a bike trainer) and my basement system I use when riding down there is a Classe CDP.5 into a a Schitt Freya pre into a McCormack DNA.5 Rev A and one pair of those same Large Advents that I had restored ten years ago (new crossovers, surrounds, internal wiring from John Van L of Van L Speakerworks, Chicago). I know the sound of Large Advents quite well.
