When I was a newly-hired EE at Bell Labs in the late 70's, there were a fair number of engineers there who built their own "Bose clones" of the 901's. I think part of the reason for this was that they were pretty inexpensive to build. The drivers (nine per speaker) were pretty cheap, and most of these engineers were also into some level of home woodworking projects. Also, these were EE's, and so I think the idea of using active equalization to overcome driver problems sort of appealed to them. I don't know if someone had "reverse-engineered" the actual Bose active equalizer, or if they just came up with their own circuit design. My early opinion of 901's was that they were pretty impressive at first listen, since you got this huge soundstage and a lot of output from relatively small cabinets (compared to other speakers of that era). But the more you listened you would hear more of the trade-offs.
As a side comment, some time after that I met with some Bell Labs folks who were working on various compression algorithms for voice encoding, and they had bought a nice pair of Vandersteen speakers to do their listening tests. I was a little jealous of them having an assignment that required the auditioning of some pretty decent speakers, as part of the job!
