Single driver loudspeakers

I know some friends who have built single driver horn loudspeakers with 6-7 inch 'full range' drive element and seem very happy with the sound.  However I wonder about those selling 94 db sensitive 12 and 15 inch full range drive elements and recommending 2-3 cubic ft bass reflex cabinets and 7 watt SET amplifiers.  Is it possible for a 15" 'full range" driver driven by 7 watt SET  to provide state of the art sound without audible distortion, deficient frequency extremes and 1950 style sound?  This is an inquiry not a critique.  Thank you for helping me to understand full range drive units.

i don't think so. :)  However, you can build your own single driver speakers fairly inexpensively and try them out. For some they are magical and refuse to ever go back to multi-way. 

Here are some basic, but good quality kits.  If I wasn't up to my earballs in speakers here already I'd be tempted to build one:
I've heard some fairly satisfying single driver speakers, but never one that met the criteria that you have laid out.
I should mention that there’s full range, and there’s full range. :) Some of the "full range" drivers actually use a mechanical crossover and tweeter, so you’d be really surprised how much has been done to stretch the technology.

When I design speakers though I try to get as much of the benefits of a single driver as I can. It’s easy to make a multi-way speaker and not at all easy to integrate the drivers so that they are not only measurably but audibly seamless. If you can tell where the speaker is, I call it a fail. This is not a problem single-driver (full range) speakers have to deal with. They do have to deal with the bass though. The usual compromise is to use a smallish driver, and rear horn or transmission line enclosure.

Still, I'm speaking outside my expertise. If you are really interested, come over to the full-range section in DIYAudio and you'll find many who will wave the flag. :)


Its not, best over all performance for widebands is the 6-8 inch consider fostex fe168esig 
Hello John,
What is your opinion/experience with the PHY-HP 12 inch driver? It has the reputation of being a superb driver. It was used in single driver designs successfully by Ocellia and Musical Affairs in their products.  97 db sensitive and 16 ohms load. 
Another variation is the "full range" four inch Jordan driver in a transmission line cabinet.  I wanna say Carolina Audio (among others) sells/sold this breed of animal.  I've never heard this type of speaker, but I once worked with a guy who owned a pair swore by it.
Check out Charney Audio, Somerset, NJ.  I own his Concerto horn speaker.  You can see my commentary on his web site.
I recently ran across the Audio Nirvana website. Anyone familiar with these full range drivers or their 300B SET amplifier which is very reasonably priced at $1550?
Thanks for all your informative responses!

I have had some very expensive multi-way speakers and when starting to design my own I saw some single driver speakers, so I bought a pair of 8 inch alnico Audio Nirvana drivers and had a cabinet builder make cabinets using the design shown on the Commonsense Audio website.  The alnico magnet drivers had a much smoother frequency response that that of ferrite and neodynium magnets.  I was completely taken aback with these, especially when mated with my JL Audio subwoofer, which completes what I consider the only real achilles heel of single driver speakers:  bass dynamics.  They can certainly plumb the depths but cannot move air like real woofers and subwoofers. So I then sold these and bought the AN 12 inch drivers and a larger (5.6 liter versus 2.8) cabinets, and they are a significant step up in most parameters.  As far as treble, after hearing these I wonder why anyone makes tweeters, even approaching the sound of the ion tweeters in a pair of Acapellas I once had.  And the midrange is simply unreal, as well as soundstaging and immediacy.  

I unfortunately cannot answer your question about the low-powered tube amps you mentioned as I use as powerful solid-state amp and a tubed preamp and phono stage.  I would think the tube amps to be a good match with the high sensitivity and easy load of the speakers.  Remember, your amp is driving the speaker voice coil directly, and IMO, I can hear what multi-way speakers with crossovers do wrong.
Make sure , on size I had cabinets custom made with 3/4 inch 
Russian birch ply  and AudioNirvanas best 15 inch Alnico driver in 
a 5.6 CF cabinet 44Tall X 18-3/4W X15  D my wife seen that I had to rearrange our little room now I have to sell them to stop the in fighting.  I am in New England .great deal if so one has a SUV .
too bad though ,stay single,
For what it's worth, here's a relevant thread that I started a couple of years ago. You might find some useful info there, too:
I find it interesting that you achieved satisfying treble performance with the 12 inch single driver. Thus my question to johnk regarding the PHY-HP 12 inch. It’s possible he may not be familiar with them.
I am using single-driver active speakers on my desktop (Sony SRS ZX-1) that sound good driven by my OTL headphone amp (Audiotailor Jade). No crossover, no output transformer = sonic benefit. I've used this (and other s-driver setups before) also to explore alternatives in my living room system. It helped me to decide to switch from solid state to OTL amplification. But I found that a single-driver approach in my quite big room (50m2) was unrealistic, and ended up with Audiokinesis front and effect speakers. Not exactly small and neat, but paired with OTL the sound is marvellous.
PHY are interesting and I have used most models inc SAG versions but over all over priced for performance given.
SEAS X-1 is a good option meets most of what owners asks for.

What a number of single-drivers incorporate to improve treble performance is a whizzer cone and phase plug.  Recently there have been developments that preclude such a design.
@rlawry is right.

Fostex, among others, uses a mechanical crossover instead. Pretty insane/ingenious.  Take a look at the spec sheet for their full-range drivers, especially the treble.  Pretty outstanding!

Take a look at Omega - wonderful single-driver speakers!