I have dabbled in single-driver full-range speakers. At least with Mark Audio "Alpair" drivers, they can be quite pleasing in the right enclosure. For me, they worked best in nearfield in MLTL enclosures. The paper coned drivers work better than the larger metal cone drivers which for me tend to develop cone breakup in the upper midrange.
The Alpair 7M works quite well in a MLTL enclosure in nearfield, Nicely balanced with a very detailed and smooth sound, reasonably deep bass, exceptional imaging. Slightly soft on top (lacks "sparkle" of a dedicated tweeter). A little "doppler-ing" but not objectionable or bad from my perspective. Very dynamic. Can sound "thin" on some recordings. Some head-in-a-vise imaging.
IMO, the Alpair 10P is the best in the Mark Audio Alpair line. Better bass than the Alpair 7M, a bit warmer tone balance but not muddy. Very smooth, detailed and clean. Quite good dynamics. Better developed / tighter / more substantive imaging - more than placement, the image has "weight." MLTL produces good bass, I'm guessing 60's. Very musically satisfying without warts except for maybe a slightly soft top.
Either of these drivers can produce a very nice single driver system. And they are inexpensive to buy and their MLTL cabinets are inexpensive to build. For just a couple hundred dollars, an audio enthusiast can experiment with single driver system to hear the advantages and shortcomings (mostly just full dynamic range). A good place to start.
And it's not necessary to limit dynamics by using low watt SET amps. I was using Herron Audio M-1 150 watt SS amps.
Footnote: I went back to larger multi-way systems since I have a large listening room and wanted to listen to the full dynamic range of a large symphony orchestra going full tilt at actual live levels. I didn't want to be concerned with a voice coil wizzing past my ear.
The Alpair 7M works quite well in a MLTL enclosure in nearfield, Nicely balanced with a very detailed and smooth sound, reasonably deep bass, exceptional imaging. Slightly soft on top (lacks "sparkle" of a dedicated tweeter). A little "doppler-ing" but not objectionable or bad from my perspective. Very dynamic. Can sound "thin" on some recordings. Some head-in-a-vise imaging.
IMO, the Alpair 10P is the best in the Mark Audio Alpair line. Better bass than the Alpair 7M, a bit warmer tone balance but not muddy. Very smooth, detailed and clean. Quite good dynamics. Better developed / tighter / more substantive imaging - more than placement, the image has "weight." MLTL produces good bass, I'm guessing 60's. Very musically satisfying without warts except for maybe a slightly soft top.
Either of these drivers can produce a very nice single driver system. And they are inexpensive to buy and their MLTL cabinets are inexpensive to build. For just a couple hundred dollars, an audio enthusiast can experiment with single driver system to hear the advantages and shortcomings (mostly just full dynamic range). A good place to start.
And it's not necessary to limit dynamics by using low watt SET amps. I was using Herron Audio M-1 150 watt SS amps.
Footnote: I went back to larger multi-way systems since I have a large listening room and wanted to listen to the full dynamic range of a large symphony orchestra going full tilt at actual live levels. I didn't want to be concerned with a voice coil wizzing past my ear.