single versus multiple driver?

Multi-driver configurations can cover the frequency spectrum better, but have problems with phase coherence, time-delay, spatial irregularities. Various technical solutions mitigate these, but cannot eliminate them.

Single-drivers have their own advantages and problems: excellent coherence and presence, but limitations in frequency response and their own coherence problems when it comes to complex music.

Coaxial drivers offer a "middle way" that overcomes some of the limitations of both approaches. They must still use a crossover, but it can be simple, and it overcomes the the multi-driver's artificiality of having musical information coming from two or more points in space.

For my ears and budget, coaxials offer the best compromise (remember that all speakers are a compromise) between the virtues of the single-driver and the multi-driver approach.

They are by definition more expensive to engineer and manufacture than two comparable separate drivers.

Try the Great Plains Audio 604-8H-II (www.greatplainsaudio.com) or the Iconic 704-8A (www.iconicspkrs.com) or any of the 12" or 15" Tannoy dual concentrics (I prefer those from the "DMT" series, made from about 1990 to 2002; others swear by the vintage Tannoy models: Monitor Golds, HPDs, etc.)

Another advantage of the coaxials is that is relatively easy to buy raw drivers and crossovers and make, or have made, your own cabinets, which saves serious money compared to buying factory-made cabinets.

Serious Stereo (www.seriousstereo.com) makes a very fine speaker based on the GPA 604-8H-II, but a pair is circa $10K, whereas you can buy the raw drivers direct from the manufacturer for under $1500/pr. and make your own cabinets.

Another advantage of these drivers is a feature they share with many single-driver designs--high sensitivity (95-100 dB), which leaves you free to use low-power SET amps or high powered solid state or anything in between.

BTW, I have no affiliation with any of the companies I mentioned; I'm just a long-time and satisfied user of some of their products.

Happy listening!

Joel.

A driver large enough to produce low frequencies has too much mass to allow for the quick movement needed to produce higher frequencies. That's why a single driver is not used, except in things like portable radios. Devices that use a single driver will be compromised too much in either high or low frequencies relative to a good multi-driver design. Otherwise, everybody would be making them.

cone drivers are usually not as linear as electrostatic drivers, ribbons or planar magnetic drivers.

so the question should include these drivers as well.
i believe cones are flawed, whether one or several.
cabinets and crossovers do not help either.

it surprises me that there are so few panel designs commercially available.

given your musical preferences, you may be disappointed.

Consider active speakers. There is no crossover and less IMD from the complex interaction of multiple drivers all connected to one amp. Tannoys have active dual concentric speakers if you are concerned about point source.