Oh, ok. One of them I see. Things are gaining perspective with your last post.
The best reason to power Klipsch, or any other speaker for that matter, with tubes is that they just sound better. Oops, that 's a subjective statement and I know "you guys" frown on that. Doesn't matter, I'll stand by it anyway.
Preference notwithstanding, modern tube amplifiers do NOT sound like their 1950s counterparts. I have a 22 watt SET amplifier that I would not be afraid to pair with low 90 db efficient speakers. And I would not have to make any excuses about the sound. Although there are some nice sounding SS amplifiers (Plinius, Coda and McCormack come to mind), I still prefer tubes for their natural tonality and ability to draw me into the music. Something SS amps, no matter how good, are unable to achieve.
So you stay with your charts, graphs and sterile SS sound. I will stay with my bloated, thick, rolled off, old school tubes. We'll both be tickled.......