Just following up on the discussion of Black Max speakers in a different thread, here are some photos of my Black Max B50 model speakers.
I purchased these in August 1978 and have used them non-stop since then, and they are as good as new, performance-wise.
Drivers: 1.5" tweeter, 5" front-firing mid, 5" rear-firing mid, 10" active woofer; 10" passive woofer. I bought these after comparing sound quality extensively in person, side by side with the best speakers of the day.
I'd have to say that after reflecting on it, these speakers probably represent the best purchase of anything that I've ever made.