Single vs Multiple driver loudspeakers...

What are the pros and cons between Single Driver loudspeakers and multi-driver loudspeakers? The arguments with single driver loudspeakers are that their simplicity makes them easy to drive, plus the x-over-less setup improves dynamics, not to mention no phase problems. The thing I read is that no single driver can possibly produce the full range of sound, and most necessitate a subwoofer. On the other hand, multi-driver loudspeakers can offer a full range, but some say that more than one driver introduces phasing problems to some degree.

I have a multi-driver system that sounds great. How would a single driver setup improve my sound, if at all? And if single drivers are that much of an improvement, why are they harder to find(at least for me)?

I have also read that multi-driver loudspeaker more than often need to be paired with a high wattage amp because of the lower sensitivity, ranging from 89db and less, while single drivers loudspeakers are great for low powered tube amps because of their higher sensitivity.

Most of this, is what I have read, but never really heard.

Can someone educate me?
There are some single driver systems that very nearly cover the entire 20 Hz - 20 KHz range with reasonable linearity. The drawback here is that they typically lack sensitivity and are SPL challenged. If one can provide them with suitable quantity and quality of power and aren't too bothered by a lack of "raise the roof" volume levels, the things that they do well can many times more than make up for the things that they don't do. I know that my perspective changed quite a bit when i heard my first "full range" single driver system several years back. Then again, these aren't really conventional or even planar type drivers, so there might be something to that aspect of presentation too. Sean

PS... Sounds like you're taking for granted that "single driver" means Lowther or Fostex type drivers according to much of what you wrote. They aren't the only game in town.
Find yourself a store that sells some single driver speakers and give them a listen with your fav music.
I own a pair made by Ocellia and another pair that use the famous Diatone driver, and am VERY happy with them. I have owned many speakers in the 30(!) years I have been an audiophile.
If you need a specific recommendation, however, try the Omega brand of single driver speakers. They are great sounding, and relatively cheap, or Cain and Cain Abbys.
The imaging of the single driver speaker is awesome.
With both speakers and electronics, usually the simpler, the better. It makes it easier to maximise the quality of the parts used, and that often leads to better sound.
Best of luck.
I'm waiting on a pair of single driver speakers to arrive in a day or so.This will be my first adventure into the world of single drivers.I've owned planars and multi driver speakers.Now it's time to see how these stack up. Nearly everything I read and heard about these speakers are positive. I'm planning to run mine with a battery powered T class amplifier. The benefits are low noise floor, lightning fast dynamics, no power cords and no power conditioning. Here's a link to checkout the amplifier Clari T Amp.
It only cost $429.00 including shipping. With the right speakers this thing is said to musically give a $6000.00 Art Audio Jota tube amplifier a run for it's money. This is coming from an owner of both!

Good Luck!
You may consider an active speaker as one or more single drivers powered by separate amplifier for each.
For low volume and music where powerful bass and high frequency are not important (or if you are an old fart who can't hear those high frequencires) a single driver can be a good choice.

However, although a full range speaker is called "single driver" I question the appropriateness of this name. The high frequency response is enabled by cone breakup where the small center area of the cone vibrates independently of what the rest of the cone is doing. Many full range drivers have "whizzer cones" to enhance this behavior. One might say that the driver really consists of a woofer area and a tweeter area, driven by a common voice coil. It is very tricky (some say impossible) to get this to sound right. You need to design a mechanical filter for the crossover, and this is a lot more difficult than an electronic one. Personally I prefer my tweeters to have their own voice coils.

Interestingly, my Magneplanar MG1.6 speaker somewhat resemble full range speakers, because the tweeter is just one area of the same mylar diaphram that serves as woofer. However, that tweeter area does have its own independent drive wires.
Gmood1, thanks for the info. What is the power output of the Clari-T amp?
Hey Gaudio_eek here's the stats.

6W into 8 ohms at 0.04% THD+N
10W into 4 ohms at 0.04% THD+N

Doesn't seem like a lot but the guys running them say it will run you out of the room with high efficient speakers.
I mean heavy metal volumes! It has been tested to run for 5 or 6 hrs before needing a charge.Which takes less than an hour.The designer quoted it may run up to 10 or 12 hrs on a single charge depending on your listening levels.
You can go to the FAQS page on the site. It will give you most of the answers your looking for.
Gmood1, thanks again. I should have asked this in my earlier post. What speakers are you intending to use with the Clari-T?
I'm going with the Omega Grande 8s. They should get down around the 40 hz threshold.Checkout this review by an AA member. Clari T Amp review
I have a trio of the Lowthers R L & C. It will be hard to go back to cones.--(Deaf old guy) These embarrass my 9k speakers in the midrange.Oh ya' nothing below 50 hrtz or thereabouts.
I have been enjoying the single driver/SET experience for about 6 months now. I still have my Maggies and Apoggees. I'll keep them all. The single driver has a coherence that I have come to appreciate after 7 yrs with planars. As far as having to add a sub, I would rather "crossover" a woofer at 60Hz or less than what most multiple driver systems do at 200hz or more. Plus, you can place the sub in its best location. As far as the upper Freq's, I haven't felt I'm missing much. I hear the brushes on the cymbals quite clearly. If I feel like I need a little more air up there, I will add a super tweeter which would "crossover" around 12khz or so. For me it would be a system that had no crossover between 50hz and 12khz which is where alot of the music reigns. I have both push-pull tube and SS that I use on the planars but the Fostex seems to sound best on tubes especially SET.
Gmood1, just look at the possibilities of using the Clari-T's. Get a killer Universal Player that can do distance adjustments and hook up several of these with single-driver-high-efficiency speakers!
Matchstikman, sorry for hi-jacking your thread.
Hey Gaudio_eek, that is a good idea! That would be something special!
Thanks for all the responses and the advice.
I've heard numerous Lowther designs and some single driver or multiple driver speakers using full-range Western Electric 755 and 756 drivers. These are interesting speakers that have an immediacy and liveliness that are almost unmatchable.

Still, the only single driver speakers that I would even consider owning would be a Soundlab U-1.
Initial impressions after a couple of hrs of listening to the Omegas. Man these speakers are excellent! They still have plenty of break in left. But the transparency and coherency of these speakers are unmatched by any speaker I have owned! This includes GMA Europas and my Magnepans. They have useable bass down to around 30 hz in my room. It's not an in your face bass. But you know it's there and it doesn't get in the way of the bass plucks or the drums.

The highs seem to have all the air I will ever need. These speakers aren't rolled off in any way.They project a huge sound field in front of you that wraps around the sides. I see why people like these speakers.No crossover sounds like a winner to me. They play at high volumes as well. Some of the negative things I've read are certainly myths. The midrange is going to be hard to embarass in this type of speaker.There's plenty of multi driver loudspeakers with more bass but not always better bass. I can't wait to hear these when they completely break in!
I have single driver speakers(Lowther) and I'm very happy with them. As reported above, the immediacy and transparency are truly amazing, as is the coherency. I don't think that I could easily return to the multi-driver type of speaker, unless it was something very out of the ordinary. This single driver stuff is really addicting, and it's hard to go back to multi driver after experiencing it. Of course, all speaker types have their strong points, and their weaknesses, but the strong points of single drivers are very strong and it makes you tend to not notice much of the weaknesses. It is worth a try to see how they sound.
I was curious enough to review the Fostex line of drivers (used in Gmood1's Omegas). They are not all that expensive (at least some of them) and I have been known to buy stuff just to fool around with. I would use models that do not have any whizzer cone. I would rather have response to only 14KHz than a rattle to 20KHz.

Of greatest note is the fact that "XMAX" (the linear range of cone motion) is tiny. One millimeter plus or minus for most models. The 8" driver FF225K (which I would select) is 0.3 mm peak! Now there is nothing wrong with such small motion (my Maggies move about this much) but unless there is a lot of cone area, as with Maggies, you won't get much volume at low frequency. What you do get may be fine, and suitable for some listeners.

Now what would be nice would be a line array of eight or more of these drivers. Alas that would set me back about $760 for one line array. That's a bit much just to play with, so I leave the experiment for someone else to do.
El: You should start studying Walsh "Bending Wave" technology. It doesn't suffer from all of the problems that most conventional dynamic drivers that you have described do. No whizzers yet you can get very reasonable high frequency extension, excellent horizontal dispersion, gobs of surface area for good low frequency extension, etc... Using this approach though, one is still limited in SPL range though.

As to more conventional designs, Nelson Pass' latest DIY speaker effort is published in AudioXpress this month. Making use of a Lowther DX55 in each HUGE and highly technical cabinet, the results are staggeringly non-linear and completely lacking in bass. After applying equalization circuitry and running a completely out of the ordinary amplifier design that is the reverse of what is commonly bought and used, the end response doesn't look bad at all. The fact that it took someone like Nelson Pass, a huge cabinet, custom built electronics and this much work to get the speakers to flatten out says gobs about where this type of driver is at in the grander scheme of things. Sean
Sean...I did learn about the Walsh driver when the original Ohm speakers were introduced, and was very greatly impressed by the sound. I could not afford them then. Their ability to reproduce a squarewave, proven by scope photos, was remarkable, although some have said that a few other speakers can do this (but I never saw their scope photos).

I do have a soft spot for FR speakers, since that's what got me going in Hi Fi. I really wish that I still had that old Wharfedale 8" with cast frame, huge magnet, and floppy flannel cloth surround. I bet it would compete with the best there is today.

As to the N Pass effort...I agree that it seems that a great deal of effort went into making the driver do a task for which it is unsuited. There are forms of music where a little FR driver is ideal. Why not use it for that music, and give it a rest when you want to play a Sousa march?
Nelson is now marketing limited edition products specifically suited to the FR ( Lowther / Fostex ) crowd. As such, this was not only "research" for his products, but also the chance to have some fun and experiment at the same time for him. As you know, he's more of an "electronics man" than a "speaker man", so i'm sure it was a nice change of pace for him. The fact that he'll end up making money derived from the research and results that came out of this "fun time" probably doesn't hurt him either : ) Sean
I was just on the Lowther America website, and they have the new Pass stuff on there.

One thing that interested me was a quote from Nelson Pass, saying,"This is the best speaker that I've ever heard".

Now if you ask me, I'd say that when respected SS amp makers are getting into Lowthers, then the single-driver market is starting to get somewhere. It has always actually "been there", but it took quite a while to get some more widespread acceptance.

Sean and Eldartford, you guys need to listen to some of this stuff. You may be quite amazed what a couple millimeters of Xmax from an 8" driver can do with 2 watts input. I'm currently filling my room(24'long, 14' wide, 16' vaulted ceiling) with my pair of Lowthers and my 2 watt SET, and it is LOUD, and it does quite well down to 40Hz, really. I can hear it out in the yard with all the windows closed, when I walk the dog. There is more to this than meets the eye.
Twl: I've heard Lowther's, but not to any great extent. I've also read the entire article that Nelson published. I've seen the response curves and have at least a decent idea of what it took to get that driver to do what it is doing. I can pretty much guarantee that there's nobody other than Nelson Pass in the entire world that is getting that type of response out of those drivers. That is, unless there's someone else out there using similar equalization circuitry and an amp that has an output impedance that is appr EIGHTY ohms.

Even with all of that and a horn mouth that is 5 feet wide and 6 feet tall connected to a cabinet body that is 9.75' tall and 4.5' deep, the speaker is still -3 dB down at appr 48 or 49 Hz. In Nelson's own words "I have been extremely pleased with the results, but i must smile when i see that all of this effort barely gets us below 50 Hz".

Other than that, i have 104 dB horns and have driven them with as much as 400 wpc SS and 35+ wpc tube. Two watts isn't enough power for a speaker, even at that efficiency level. That's because 104 dB's @ 1 meter becomes appr 95 dB's at a 10' listening distance. While this is pretty loud for most people, it is nowhere near the levels that one hears at a live orchestral performance if sitting reasonably close to the performers. This is not to mention a live jazz, blues or rock show either.

Besides the spl levels, with only 2 watts, one is pretty much guaranteed to run the amp into compression and clipping on a regular basis. On top of that, feeding that much steady state power into an excursion limited Lowther is going to create dynamic compression and introduce other forms of distortion into the equation. This is why, even though he had a GIANT horn doing all the work and keeping the driver properly damped and loaded at low frequencies, Nelson Pass stated "Still, they play loud cleanly in a manner that Lowther owners don't usually encounter, and the cones are barely moving". Without the aid of a horn this size, there is just no way that the Lowther can produce ANY type of bass and / or high spl at the same time.

As a side note, Nelson provided the readings as taken from a Lowther in a standard sealed box. Using the output at 1 KHz as a reference point ( industry standard ), this driver is down appr -15 dB's at 100 Hz. By the time we get to 40 Hz, we are down almost -30 dB's. That's why he couldn't squeeze ANY deep bass out of the driver, even in that phenomenally LONG and HUGE horn.

Needless to say, i DO like some of the advantages of a single driver, but i also realize that, at least at this point in time, none of them do everything well. If you want extension, you give up efficiency. If you want efficiency, you give up extension. They are all a trade-off, some to a greater extent than another. Sean
It just isn't fair to force an excellent midrange driver to perform woofer and tweeter duty. IMHO.:-)
Okay, I suppose we just have drastically divergent listening needs.

Regarding some of your other points, the Lowther isn't really designed for front horn loading, and nearly all of the cabinet designs for Lowthers have rear loading of one kind or another, which is supposed to augment the gradual rolloff below 500hz of the front radiator. The rolloff is well known, and is accounted for by the rear-wave horn or TQWP loading.

I think that some of the nuances of this kind of system is not understood by many people who seek "perfect" response curves and the like. The purpose of this kind of system is the utter simplicity, and the acceptance of less than perfect response curves. It is this seeking of "perfect" response that has caused most of the mediocrity of "mainstream" systems. To get to this perfect flatness, or perfect this or that, ends up sucking the life out of the music, because of all the increased complexity and band aids included to try to attain that at the expense of all else.

I suppose that I must admit that what many would call a "ragged" response curve is okay with me, as long as at least a small portion of the life of the music is still left in it. Call me crazy, but flat response that is virtually lifeless is not my bag. I can see that flat response is very important to some others, so I have no problem with that. But that is not what I want, if it means that I lose what means more to me about the music.

I guess it comes down to what is important to each person. The 90-95db peaks at my listening chair is just fine with me. Suits me fine.

Maybe Nelson should have tried a Voigt Pipe. I have no problems at all getting under 50Hz quite easily, with authority. Lowther EX3 drivers begin audible compression at 108db, which is above my amp's ability to produce, so no worries there.

Somehow I've deluded myself into thinking that a very musical 95db at my chair with a somewhat imperfect response curve can be a quite exciting form of audio enjoyment.
Fancy that.
I wonder how that could be, after all these years of listening to more "normal" and "perfect" and expensive high end systems?
Maybe there's just some unknown aspect to it that intrigues me.
I always thought this poster nailed it, at least as far as SET amps (which are often paired with speakers like single driver units or speakers without crossovers). link= "Reasons why I like SET topology so much"
That's a very nice post you dug up Aroc! Amen Twl!
I am NO fan of "sterile" sounding audio systems, regardless of how well they measure. Music is neither sterile or boring and in order to reproduce it as it was recorded, a system needs to maintain a high level of accuracy. Combining the two aspects of reproduction ( musicality and measurable accuracy ) gives us "musical accuracy". Sean
Twl: By the way, Nelson's comments about this being "the best sounding speaker he's ever heard" has a LOT to do with the linearity of it. After he was done combining equalization and amplifier loading characteristics, that speaker was VERY close to being "flat". While he did comment on the lack of bass, he's taking care of that in his next article. That is, he's going to bring in "El Pipe-O", which is a HUGE vertical pipe housing a sub that he built a while back. Sean
I readily subscribe to El's opinion,
It just isn't fair to force an excellent midrange driver to perform woofer and tweeter duty
and would add, it's not necessary, either.
The average Lowther, Supravox, Diatone, AER, etc will get you through the dangerous 150-8kHz region famously, even without a wizzer. Sensitivity is usually well over 95db and many of these drive units allow 30+W rms, offering a prodigious dynamic range, comparatively speaking.
Cut the low Xmax FR at ~150, and leave it alone n the highs. One can easily add low frequency energy to a FR using a pair of (active) subwoofs, either a W horn or open baffle.
A super tweet, while difficult to place (wave lengths at 8-12kHz are VERY small), will do the job once you calculate its position precisely (there's always some elbow grease & maths when it comes to spkrs!).

And, you're set! Lowther PM5 & EX4 (that I'm familiar with) have no trouble anymore reproducing the complexity of a full-scale orchestra -- add a chorus too, while you're at it.
The dynamics are incomparable, of course!
Well we have some Lowther fans here. I bought mine to just fool around with. I stuck them in an empty room, with a receiver--for breakin.Every couple of hours I'd sneak in for a listen.It wasn't long till I moved the Montanas to make room. That was the week before Thanksgiving. I haven't changed the Montanas back yet. To me the simple description would be--These speakers emit a set-sound even when driven by a ss amp.----In my case a Marantz receiver. No matter what the numbers say it's the music and does it sound good?? Way simple,huh?
Gregm: According to the chart that Nelson Pass had published in that article, the Lowther DX55 showed a gradually dropping slope below appr 700 Hz. As compared to the average output levels in the upper midrange & treble regions, output was down appr -4 dB's at 500 Hz and appr -13 db's at 200 Hz. As such, without some type of equalization circuit, the usable bandwidth of this specific driver is much narrower than what you've described.

For those of you that are "into" the full-range driver approach, AudioXpress recently had an article about modifying a small Tang Band driver. After modifications, it was FAR more linear than any Lowther i've ever seen and even had greater bass extension and linearity. The fact that it is only a 3" driver severely handicaps the ability to achieve the spl's and / or dynamics of the much larger Lowther drivers. Once again, we come back to the fact that there are trade-offs with ANY loudspeaker design and they become even more complicated as one reduces the number of drivers used.

It's too bad we can't find some way to make a plasma driver both more efficient and wider bandwidth. This would solve all of our problems. Well, that and getting rid of the excess ozone that they generate : ) Sean
I just read Nelson Pass's writeup on his "Kleinhorn". Surely this was intended for the April issue of some magazine.
The article was published in the January 2005 issue of AudioXpress, complete with photos, text and test results. It is no joke as can be seen by the end result. Sean
Sean...Any wife will tell is a joke. As NP himself says..."I have to SMILE when I see that all this effort barely gets us below 50 Hz".

Somehow the use of a long horn to enhance LF response seems inconsistent with what the FR people cite as the main benefits of phase shift due to a crossover, and colocation of LF and HF sound generation.
Has anyone tried the Manger or KM-50 mini drivers in a DIY
I've never seen very much on the Manger's although the design intrigues me. John Curl has made some very positive comments about these drivers and their potential, but once again, they are limited in terms of spl and extension. The articles that i have seen have suggested using multiple Manger's to get around this problem, which somewhat defeats the purpose of using a full-range driver. That is, the point source radiation pattern is lost with more potential for phase related cancellation issues. Sean
Manger has a pretty cool concept with their wave-bending transducer. It seems like it would have alot of interest, but the high cost might get in the way. The drivers cost quite a bit for experimentation purposes. Most of the info that I've read say that they are only good above 100Hz, and need a sub.
Sean & Twl- thanks for the feedback. The Mangers aren't that
much more expensive than the Lowthers, and with dual subs
and digital crossovers, I don't need response below 100Hz.
I'm just wondering if the high frequency response is better
than the Lowthers.
I've had the pleasure of hearing a pair of Overkill speakers that utilize a manger driver plus a conventional dynamic woofer. The manger driver sounds terrific -- very dynamic and clear sounding. The only significant downside was a touch of hardness (perhaps a narrow band peak of some kind)and severe beaming of high frequencies.

By the way, you can count me in the high efficiency/SET camp.
I attached the Decware 'gizzmos' to my dx3 drivers. Funny how such a thing can improve the band as much as it has done for me. There is an article on the Decware site describing the giz-thing. It seems to go against the grain;but, with great results.