+1 @yogiboy Awesome writeup and spot on.
Back in the early 80’s, I ran my 901 equilizer and dbx 3bx range expander through the signal processing loops in my SoundCrafsman SP4001 equalizer/pre amp. Those were the days.
I had the original 901’s with the chrome stands. I would sometimes turn mine around for direct sound when we partied like it was 1999. But most of the time I played them in the reflex position. I also found they sounded like crap without the Bose equalizer.