Experience with single-driver speakers?

[tfarney]

Have I asked this before? God knows I've thought about it. I've come really close to pulling the trigger on a pair of Tektons a couple of times, but I've chickened out. I keep coming back to them because I don't care for exaggerated "airy" highs; I seem to get by pretty well without organ-pedal bass, and I love the fluid purity of mid range that comes from a good pair of headphones, with no crossovers messing with the SQ and no radically different drivers competing for the same space. I suspect what I really need is a big system with nearly full-range mids and crossovers to tweeters and woofers way above and below the sweet spot.

 

But as you know, I'm cheap.

 

I keep chickening out because I read that they are only great in a fairly narrow band of simple music -- vocal, acoustic, jazz...no heavy electric or symphonic need apply. I guess I could always pop on the cans for those 70s King Crimson moods, but it worries me and I bail. Twice already. About to go for a third.

 

Anyone have any direct experience with this kind of speaker?

 

Tim

 

[The Computer Audiophile]

No experience with them other than at CES. I've always considered them too limited for me.

 

I wonder why more manufacturers don't produce them.

 

[tfarney]

I think they're just not a mainstream thing, Chris - even in the very limited "mainstream" of the audiophile world. "Limited" seems to be a sort of consensus, really. Even among the folks who love them. They often talk about what they're good at and that they're not for everybody, etc. Yeah...I'm gonna back away again, I believe, and go for something conventional. Thanks for the input.

 

Tim

 

[The Computer Audiophile]

Hey Tim - Now that I think about it your want for single driver speakers is the exact same thing as my want for a 300B amplifier. The 300B amps can only drive a handful of speakers, but to me the sound is fabulous. I've tried to squeeze some 300B monoblocks into my system more times than I can't think. This was all in my head of course, and I never pulled the trigger on them.

 

As a side note did you know the 300B tubes are the only tubes ever designed specifically for audio. One of the guys at Manley told me that.

 

[rom661]

Tim - a full range single driver is the holy grail. I have done speaker design for about 25 years and the best crossover is no crossover. There was an English driver about 25 years ago that was close to being full range. I think it was called a Jordan. The problem is that a driver big enough to handle any kind of bass response is too "slow" for good high end response and is very beamy. When the wavelength of a frequency approximates the diameter of the driver the response narrows. As the frequency increases the driver delivers a very narrow response, kind of like a flashlight. Move a few inches off axis and the high frequencies disappear. Many electrostatic speakers suffered from this. My wife once accurately described a pair of electrostats, Accoustat, I think, as the world's largest headphones.

 

There are some new drivers that purport to sidestep the issue. The most promising is the Manger, which is very nearly full range and is star shaped. I briefly owned a pair which were crossed over at 200Hz to a couple of Scanspeak woofers. Interesting, but ultimately not good enough in my estimation and extremely expensive.

 

A reasonable compromise is a very wide range midrange driver with a first order crossover. This addresses the issues that the laws of physics present (they are more than an idea, they are laws) regarding dispersion characteristics and transient response, while providing many of the attributes that are desirable from a full range driver. I did a design many years ago that crossed over at 200Hz and 5KHz. Most of the music was covered by the single wide range driver and the first order slopes and time aligned drivers had a minimal effect on the aspects of a full range driver that were desirable to begin with. It did have its own set of compromises, mainly in terms of limited dynamics and a fairly narrow listening window.

 

I realize that you asked what time it is and I just told you how to build a watch. Your desire for a full range driver is valid. Getting there is the problem.

 

Best wishes

 

Rick

 

 

[The Computer Audiophile]

Hey Rick - I was hoping you would jump in on this one. considering your speaker building experience, successful or just short of successful :-), I knew you would have some good details for us. Thanks!

 

[tfarney]

Rick, thanks for the lesson in watchmaking. I think I needed it. I've danced around Eric Alexander and his Tekton single driver speakers, a couple of times, because of my hope, to quote your wife, that they are the world's biggest headphones. I love my Senns with enough power behind them. They're a bit rolled off at the high end, but I don't mind much, because the bass has depth and slam, the detail and micro dynamics are plapable, and the mids are sooooooo pure. My latest dance with the Tektons is around the nearfield system I'm building. The proximity would, of course, mitigate the dispersion issues, but it wouldn't add any bass or, perhaps more importantly, dynamic range.

 

I'm gonna chicken out again, but the concept continues to appeal to me on some deep theoretical level.

 

Tim

 

[baxtus]

Friends, my small contribution...

 

There have been very few systems that have ever communicated the essence of music (live or contrived) to me at all (especially in the so called "high end").

 

There are five that I remember and the one thing they had in common was that they terminated in single driver speakers:

 

My parents ancient 1960's sound system built by a college professor friend of theirs.

A system comprising the original Quad II amplifiers and electrostatic speakers.

A system comprising 25 watt triode VTL mini mono amplifiers and Quad ESL 63 speakers.

A system with 300B tube amplifiers and Lowther drivers. (Do not know the enclosure design).

My own JVC UX 7000 micro system which has single driver, ceramic cone speakers which, in the main, tell the truth.

 

I have been addicted to music from birth. My children share the same addiction. They, like me, feel that life without music is nothing.

 

I would pursue the investigation into single driver systems if my sole intention was to "connect" in a meaningful and emotional way to the original intent of the recording that the artists and composers poured their souls into.

 

[carlseibert]

Hi Tim,

 

A buddy of mine and I are building Fostex-based single driver speakers as we speak. We're wondering all the same things that everybody else does. They should be ready to listen to in a couple of weeks. I'll report back here on what transpires. The cabinets are an interesting shape. If they completely tank as speakers, we can always make grandfather clocks out of them ;-) All, or at least something, should be revealed soon.

 

-Carl

 

[Wavelength]

Gang,

 

I have designed like 22 different Full Range systems. My fist design was with the Corel Drivers they were really nice. I did allot of design with Lowthers but did not really care for them. The Diatone P610MB are great little drivers. They have been making them in Japan for over 58 years.

 

You may have seen the speakers I designed for Terry Cain the Walla Walla Wall of Sound which I have in my living room. I also designed the Vaughn speakers that we used at CES. These came from a concept I called augmented full range drivers. Basically padding the top and bottom end with extra drivers.

 

The WWWS are flat to 30Hz at -2.8dB and 18K at -3dB and are killer on the long wall (which was my problem with the room).

 

FYI I do not get paid for the WWWS I did these for Terry who was great friend of mine. Plus I needed a speaker for my room (I also paid for that pair).

 

I did a number of back horns now with the 168 Sigma driver which is my FAV as it is the best of the diminishing returns for highs and lows.

 

But do note sticking drivers in different back horns is silly it will never work. Each has to match the driver and the properties it needs.

 

Also stay away from the horns were the throat is immediately met by a 90 degree turn. Voigts first rule of back horns was that the first corner needs to be as far away from the throat as possible.

 

Also most of the Fostex and Lowther drivers have too low of a Qts to be used in a sealed, ported or TWQT enclosures. In these cases the driver does not match and therefore suffers somewhere, usually in the bass.

 

Well back to work...

 

Thanks

Gordon

 

[tfarney]

Well, Gordon, most of that was way over my head, but the single-driver speakers that have drawn my interest a few times are these....

 

 

 

They're Tektons, from a guy named Eric Alexander. I've even gotten far enough down the obsessive road to talk to Eric on the phone a couple of times. He makes a bigger one with the 6" Fostex with the whizzer, but he recommends the 4.5" over it if you can do without the bass and volume, because he belives the mids are sweeter and it images much better.

 

Tim

 

[Wavelength]

Tim,

 

Wizzer's suck... I designed a FE127E that uses a passive radiator and it sounds great. This driver while not as good as the Diatone is really pretty full range. Fostex has a cabinet design that uses a 6th order porting design that get's the bass down in the low 30's, but the cabinet is pretty complicated and has an internal port.

 

You may want to use a sub with something like these but who cares the main thing to think about here is that nobody who designs speakers thinks of the fact that midrange is NOT 1khz.

 

Low E on a guitar is 81hz, male vocals start at 120hz and female at 220hz... think of it this way middle C on the piano is like 220hz. Why do all these designers put the xover at 400Hz... man what were they thinking.

 

My thesis in college basically determined that all speakers should be xover below 100hz and above 10KHz for the best results. This is what the Vaughn speakers are based on.

 

Have fun they look great for the price.

 

Thanks

Gordon

 

[tfarney]

Well, Eric Alexander, who designs and builds them, won't come right out and say wizzers suck, but if you pick up the phone and talk to the guy for awhile, you get the definite impression that he builds the speaker with the 6" Fostex in it for people who insist upon the extra bass. He does not recommend it.

 

See what you've done? Now you've got me thinking about it again. The price is right, but there are some surprisingly good small 2-ways being designed in the US, Canada and England, and manufactured in China that are even cheaper...

 

The 4" Tektons claim +/- 3db from 55hz to 17khz. I'm not convinced that at this point I hear anything over 17khz. And this is for a nearfield set up on a big desktop. I'll get some bass enhancement from them sitting on the desk, just inches from the back wall. They'll be 4 feet from my head, so volume should be fine. If I still missed the bass I could always slide a small sub in under the desk and cross it over at...what, about 50hz (what does "continuously variable crossover mean, by the way)? Would the dynamic range be comparable to a two-way with a 6" woofer, or would that suffer a bit? Oh yeah...what is a "textbook Quasi third-order ported Butterworth alignment?" Oh what the hell, all ye who art smarter than me, do you see anything to recommend or warn against in this product description:

 

Superior quality Fostex FE127E 4.5” (114.3mm) full-range drivers to provide an unsurpassed level of output, fidelity, and detail all the way up to 20kHz

• Warm and rich bass response that is produced by a textbook Quasi third-order ported Butterworth alignment, and at the foundation is the top-quality MDF cabinet, with fiberglass damping

• An oversized port that eliminates all possible vent noises

• Gold plated 5-way binding terminal posts

• Completely designed, critically voiced, and hand built by a master craftsman

ll-Range Fostex Monitor Specifications:

• 17.00” (431.8mm) tall x 7.25” (184.1mm) wide x 10.25” (260.3mm) deep

• 45 Watt RMS power handling, 91dB average sensitivity (93.6dB peak), 105dB maximum output (each). They are totally compatible with all higher Wattage amplifiers, just use caution at higher volume levels.

• 4.5-inch (114.3mm) Fostex FE127E Full-range shielded transducers with superior/natural damping banana fiber ES cones

• Incredibly linear frequency response! 55Hz – 17kHz @ +/- 3dB (2pi), better than +/- 2.25dB from 108Hz-15.1kHz (2pi), -10dB point is 45Hz, a perfectly benign 8 Ohm system impedance that is ideal for single-ended triode and push-pull topologies.

Top-quality MDF cabinet/bracing materials: (Density (p) = .75, Young's modulus (E) = .33) (BETTER THAN SOLID OAK!)). Finished in textured black satin lacquer. Each cabinet weight is 16 lbs (7.3kg).

• Proprietary internal wiring using Mil-Spec premium conductors that are ultra pure silver coated copper with pure Teflon dielectric insulators - completly point to point soldered

• Honest and accurate specifications, data, and measurements. Proudly hand crafted in the U.S.A.

 

Yeah, you've definitely got me thinking about them again. Treacherous tempter...

 

Tim

 

[tfarney]

One more question, while I'm annoying all of you -- those who are familiar with single driver speakers, how much truth is there in the rumor that these drivers have an excessively long burn-in time? How long? Moderate volume ok?

 

Tim

 

[rom661]

The Martin Logan Summits 10" woofers, 1 forward firing, 1 downward, are driven by a class D amp and cross over to the stat panel at 380Hz. They maintain it is a reasonable design. They're trying to keep the panel as narrow as possible, of course and have to go higher to avoid cancellation. I maintain that it is whack and pointed that is is substantially above middle C. Oh, well.

 

Rick

 

[carlseibert]

Hi Tim,

 

I can't really address the break-in issue directly. My drivers are modified. They're now on their second round of burning-in. The fellow who modded them says he ran them for 200 hours and that they require a second break-in period after the mod. Thus, they're hooked up to a cheap tuner in the garage. He was definitely right about the post-mod round, at the least. They were pretty scary for the first couple of hours. Then I heard an abrupt change - I could tell that something had changed through the garage door! They've changed a little since, but nothing as drastic.

 

I'm getting the impression that they will be pretty good. The midrange sounds nicely detailed, dynamic and maybe on the warmish side. There's no high treble to be had from a tuner like this one, but so far the mid-treble seems to sound pretty much like the midrange - coherent and quite listenable. The lower midrange through mid-bass sounds quite weighty and full, but there's a boominess lurking about that may be a resonance that needs to be addressed with damping or may just be "dramatic" processing, courtesy of the radio station. We'll see.

 

On Friday, their sentence will be served and they'll come in the house to try them in the room and start to figure out cabinet treatment and whether they will need a baffle-step compensation filter.

 

More news as it happens...

 

-Carl

 

[carlseibert]

Hi All,

 

The FE127e-based Metronomes are playing as I write this. They're pretty impressive, as it turns out. These things offer a fair dose of the magic for a couple hundred bucks for drivers and a sheet of plywood from Lowes. I get the single-driver thing now. Here are some early impressions. Tim - I don't know if any if this rambling will be helpful for you, but here goes.

 

There's resolution to the max. Midrange dynamics are what they should be. Imaging is very good. The bass is full and satisfying, if not the last word in power or control - more on that later.

 

Overall, the sound is very involving, toe-tap-y. M Ward's "Helicopter" played on random play. It had me snapping fingers and dancing around the den. And this is not what you would call a dynamic recording. My copy is an MP3 from eMusic at that.

 

The first thing that grabs you is the detail. We're talking a level of resolution and coherence that's in the same league as the Apogee ribbons in my main system. We're talking in the same league as good headphones, for crying out loud. I'm waiting to hear the lower midrange thinness that usually lurks around components that are "detailed". Haven't heard that yet. No, this is the real detail deal. Vocals, particularly, are spot-on. Performers breathe, make sounds with their mouths and just palpably "exist", right there in the soundstage. The handclaps in the background of "Jersey Girl" by Holly Cole on "Temptation" sound like - hands. Clapping. Real hands clapping. Right where they should be. ( I have no idea how much of the soundstage is a reproduction of what happened in the real space when the recording was made of not. Doesn't matter. It sounds convincing enough to suspend disbelief. That's what matters.)

 

Familiar vocals sound like the vocalists who perform them (like they do live, or like my accumulated impressions from lots of recordings played on lots of systems) Margo Timmons and Natalie Merchant on the Cowboy Junkies' "Trinity Revisited" serve to illustrate. It's Timmons and Merchant, as vividly drawn as they would be on my AKG 701s (same DAC, but the headphones enjoy somewhat more upscale amplification.)

 

Still worried about brightness or etch in the upper mids passing as detail, I tried some harmonicas. William Gallison and Toots Thielemanns. An over-bright Toots Thielemanns is like a ice pick through the brain, you don't have to wonder if something bad is happening. I put on "East Coast, West Coast". I sat and listened to the whole album. The cat jumped up on my lap and listened. No brightness problem.

 

I put on U2's "Rattle and Hum". My wife stopped work and came into the room, sat down on the couch, and proceeded to sing along with Bono. I have no idea what U2 on this system sounded like, but I guess it the singing I did hear was an indication these things can't have been too bad on the "musically involving" front.

 

I tried the "Scherherazade". (Which, by coincidence, is playing at background level by choice of Slimserver's Random Play as I type this paragraph). At reasonable (e.g. pretty loud) levels, the weight and power of a real orchestra, or for that matter, a really good system, was absent, but melodic lines unfolded to be followed, and oh that low level detail. Subtle parts were as good as they would be on a big-buck system. Overall, worse things could happen.

 

Now then. the bass and treble. Treble, at least as far as it goes, is a delight. It's of the same smooth, detailed cloth as the midrange. Wooden sticks hit metal cymbals with the right timber and bite. That said, I'm pretty sure the last half-octave, at least, is missing in action. There could be more air around instruments. But my very humble, no-name Chinese push-pull amp isn't much in the last octave anyway, so it's hard to really tell what the speakers are contributing or subtracting. Bottom line: The top end is rolled off, but I not grieving for it.

 

Bass is interesting. F3 for these speakers supposed to be about 50 or 60-Hz. So, I would expect a lightness in the bottom that would extend up to thin-ish lower mids or a one-note thump. But noting nasty is happening. The bass seems full and rich and quite warm. It's not tight or powerful in an absolute sense - Richard Vandersteen doesn't have to worry about losing Quatro sales here. For that matter, the bass from my Apogee Caliper Signatures is faster. Like an Indy car flying by my sedan, faster. But the cost of one or the other of those systems and the amplification to drive it would be thirty to sixty times the cash spent building these things, so I would expect them to be, ahem, better.

 

I heard a boominess when the speakers were burning in on radio in the garage that made me think a half a bag of polyfil would be in order to damp a pipe resonance that's flapping about. I don't hear that as much on real loss-less music from my server. I guess the radio station's idea of appealing EQ just hit the right note over and over. Somehow, with all the listening this afternoon, I didn't quite get to the store to buy that bag of fuzz. I'll get to it. It remains to be seen if the damping will tighten things up or take away some liveliness that's part of the toe-tap appeal. We'll see.

 

So there's a preliminary take on my first DIY single-driver experience. I hope it helps a little, or provides some amusement or something. I'd like to thank the great people online, at the DIY Audio forum and particularly Dave at Planet 10 Hifi, all of whom have given of themselves to make this hobby accessible to people like me and you. The world may be falling apart in some places, but the sense of community we see on fora like this one makes me feel better about our chances for the future. I feel like it's the least I can do to report back, at least as well as I can, on what the results actually sound like.

 

Cheers,

 

-Carl

 

[The Computer Audiophile]

Hi Carl - Nice detailed post. I'm not big into single driver speakers, but I am sure interested in them after keeping tabs on this thread.

 

Thanks for taking the time to write such a complete review/impression!

 

[tfarney]

Thanks Carl. That actually helps a lot. What you're describing is very appealing to me. Like I said, my purpose is a near field system. A lot of volume will not be necessary. Sensitivity and full dynamics and moderate volume will be critical. The speakers can sit directly on my desktop, just a couple of inches out from the wall, so I should get some bass reinforcement. I don't even want airy, extended highs; they make me crazy. What I want is a smooth, coherent midrange and vanishing cabinets - from double bass up to maybe just a touch of the natural sibilance in a woman's voice, laid out in a nice field about six feet wide and 3 feet deep, hovering over my desktop. I'm not asking for the world, but within those parameters, I'd like to push at the edges of perfection. I want a kick drum to have adequate kick. I want the purity and presence of Miles' trumpet and Emmylou's voice to take my breath away.

 

And I want to spend about $400...

 

 

Tim

 

PS: Eric Alexander's break-in recommendation is speakers facing each other, 1/4" apart, blankets thrown over them (a domestic tranquility adjustment), pink noise and moderately loud volume for 48 hours.

 

[carlseibert]

...one potential negative I didn't mention is that they are pretty beamy - just about what you would expect from a 4 inch wide tweeter. On the one hand that's good in that it gives some "EQ-by-toe-in" control. On the other, you don't get a very wide sweet spot. Probably not a problem if they are on either side of your monitor.

 

I had never heard a single-driver speaker until we built these. I'm pretty psyched about the concept now. I'm already thinking about finding a design for some itty-bitty ones for computer desktop use.

 

-Carl

 

[rom661]

Connect the two speakers under the blanket out of phase and the low frequencies will cancel one another even though the voice coil is still passing current and there is still excursion. Quieter in the frequencies that the blanket can't absorb (longer wavelengths)so you can turn it up louder.

 

rick

 

[Innertuber]

Hey Tim,

 

I've got 2 of the 4.5's and a matching sub still sitting in their boxes as we haven't had time to fiddle yet (Just back from 2 weeks in Amsterdam).

 

Also have a batch of new vinyl including my late Christmas present of the Doors set. I'll let you know how they work for me.

 

I'm intrigued by the full range idea, but added a sub to cheat a bit.

 

George

 

[tfarney]

I'll probably add that cheat in time. You got a powered sub from Tekton? Do you mind my asking how much that was? And at what point it crosses over?

 

Tim

 

[Innertuber]

If I recall right it's a 300w BASH amp sub. I paid about a grand for the sub and two speakers, but I ordered a translucent finish over a wierd maple. I'll check on the crossover.

 

http://www.computeraudiophile.com/node/256#comment-1907

 

[brucemax]

I have listened and currently own two 2 single driver speakers, the Cain-Cain Abby's and the DecWare HDT's. I am driving them with either Transcendent Single-Ended OTL Amplifier or a pair of Bottlehead Paramount amps which I have built from kits. Both turn out to be excellent, have that "bring it back alive " performance and do not break the bank. I have done the expensive, inefficient multi driver speakers with big solid state amps thing and do not miss them. For a fraction of the price I get much more realistic music reproduction with the simpler system(s). Don't be afeared of walking off the standard path. Pull the trigger and enjoy.

 

Bruce