The Bose 901s are some of the least flat speakers ever made. To get around this Bose includes an EQ to flatten their response. They're so bad that there's not enough headroom in the auto-EQing systems of today's receiver to correct them. So one must use the tape-loop to insert Bose's EQ into the signal path. Too bad no one builds receivers with tape-loops anymore. Additionally the amount of gain applied to some of the audio bands reduces the headroom of the amp in the receiver and can cause it to distort/clip.
The 901s were Bose's first foray into gimmickry.
Well we were in college in the '70s.......close to the '60s - so it all sounded good mainly because it was loud. Plus, we thought the equalizer was "cool". The other guy on the hall had JBL 300s and there was always the argument over which was better. Of course in the 70's it was before Al Gore invented the internet
where I could ask more informed folks such as the ones here.
