I agree with everything said having owned Apogee Diva's and Centaur Majors. The Diva's were powered by a Classe Omega Stereo Amp 450wpc into 8ohms and 1800wpc into 2ohms. I preferred the Classe Omega Sound to the Krells I had KMA 200's and 750mcx's and to the Pass Labs XA600. The Pass had problems handling the load, I would get high end distortion and ringing. It may be the amp having problems with the low impedance causing the problem. My friend had a pair of Scintilla's that he powered with a Pair of Classe Omega Stereo amps and loved it. He preferred it to his Krell Evolution One and Two setup that he wound out selling. I do have my Classe Omega Reference Mono's for Sale that are stable to into a 1 ohm load and put out 4000wats at 1ohm. The Classe's definitely make Apogee's sing. As for if there is a problem its typically with the bass panels, but they are repairable!
http://www.reality-audio.com/apogeerepairs.html
Here is the link to my ad for the Classe and Stereophile review.
https://www.audiogon.com/listings/lisbfgie-classe-omega-reference-mono-s-beautiful-amps-solid-state
https://www.stereophile.com/content/classé-omega-monoblock-power-amplifier
Good Luck with your Purchase. I loved the Apogees and currently own Martin Logan CLX Arts ( .7ohm load problem, lol) that I am using with custom made Dipole woofer towers, they sound incredible! I almost just bought a pair of Apogee Full Range because that is how good my Diva's were but decided to stick with my Logans.

