I've owned Bose 901 since 1970 so I know exactly what I am talking about. I also own and listen to other speakers. Recently I moved mine from my 20 x 20 bedroom with relatively dead acoustics to a 14 x 14 room which is on the live side. They are being powered by a Marantz SR 930 Receiver. I've been experimenting with biamplifying them using additional outboard tweeters similar to Audax AW010E1 and Dayton 275-065 four in parallel per channel---three indirect firing one direct. I have always maintained that the one real shortcoming of Bose 901 series I and II was the treble because of the high inertia of the 4 inch cones being unable to produce the highest octave of sound. My tweeters are crossed over at 6 khz and additional overall equalization is used to improve tonal accuracy. The results are outstanding. Easily a match for most loudspeakers available today and producing tremendous bass far surpassing most dedicated subwoofers. The only loudspeaker which outperforms them in bass response that I have experience with is my enhanced Teledyne AR9s. You won't find much at any price that compares with that, it is earthshaking.

A lot of people who don't know much about Bose 901 have loved bashing this product. And I must add that the versions from series III to VI are too expensive, not accurate enough, and no longer have the capability of reproducing low frequencies that series one and two did. I would not buy them today.

However, the original version when properly enhanced is IMO opinion an outstanding sound reproducer and there is no doubt of it.