mdrew, thanks for the clarification. I can only rely on my own experience with the 80's. I've driven them with a late 1980's Luxman 2ch integrated amp, and an early 2000's Yamaha 6.1 receiver.

With the Luxman, as I turned it up it would really sing. It stayed clean and controlled. Sounded awesome. Push it a little more and 'click' - off it went. Turn it back down, and within 10 seconds it was back on. It was NOT rated for 4ohms and when pushed, ran super hot. (Currently, it's driving my M3's in the office.)

With the Yamaha, when it's pushed things get nasty. The highs sound raw and really rough, and the bass is distorted. I've gotten it up to -8db, and I thought "Why?". I usually run it around -20db which is plenty loud enough for movies. (Lower when the family is around) But for music, at the levels I like to listen to, I NEED more power. (The area is ~12,000cuft) For most day to day listening, I'm happy with the Yamaha. It sounds great so long as it isn't pushed hard.

As a side note, the Yammy runs fairly warm, but has never shut down.