There is a simple reason why the venerable Bose 901s are still held in high regard by those in the know, and why Magneplanar loudspeakers constantly rate highly in the "low" end of HiFi: their cross-over points, or - in the case of the Bose 901s - the lack of a crossover altogether.
Human hearing is most sensitive at 2kHz to 3kHz, the frequency where - and it is hard to fathom why - most two-way loudspeakers cross over from their woofers to their tweeters! The woofer does bass and mids, and the tweeters do treble - and also mids! A recipe for disaster, as we all have heard.
The 901s not having this problem still manage to put a smile on the face of people who hear it with an open mind (but not "audiophiles" already biased against everything Bose).
If you do a simple Google search, there are now many instances of single-driver "full-range" systems available for the audiophile.
Into this strange group of loudspeakers, the lower end Maggies jump in and cross over at 500Hz. Yes, its "tweeter" is also its midrange - hence the effortless quality of vocals reproduction when paired with even half decent electronics.
Into this rare club now joins Manger loudspeakers from Germany. They have a single driver model, but their two-way systems cross over to a conventional woofer at a low 360Hz.
They're winning rave reviews and, like the Bose 901s and Magneplanar .7s, SC-HiFi are happy to recommend them to the discerning listener.