Speaker design is like rocket science; really, I’m being serious!
The most failed high-end endeavor has got to be speakers. From the extremely inefficient and difficult-to-drive, to classic and avant-garde horns, speakers are all over the design map and price points; and, all have failings. Because we have such wildly differing rooms, hearing, prejudices and systems, there will always be the need for a vast selection of speaker systems. What might be a design virtue for one system might be the flaw in another, so the designer can only abstractly approach the speaker craft. He/she will design for a given crowd, a clique really, with a certain budget, with certain size rooms, and with particular prejudices about what a “perfect” speaker should be. There are idealists who create speakers that require owners to make accommodations for room treatments, positioning, particular amp choices, furnishings and even the type of music. While I appreciate the idealism, these speaker systems are ultimately doomed to failure by eliminating thousands of possible buyers with every additional requirement for his speaker design.
The enthusiastic DIYer will get the idea that speakers are somehow easy because they are less intimidating than electronics; but trust me, electronics are way easier. All you need to build a decent preamp or amp is a handful of good quality parts, a chassis and some wire. And start cutting and pasting. With the same set of transformers and tubes, you can make hundreds of amps with different variations on old designs that go back to RCA Theater, Altec, Peerless, Western Electric (their PP 6L6 amps), Marantz, etc.. You can configure a phase splitter about a dozen ways with half of a 6sn7, or a whole 6sn7. The same pair of output tubes and ultralinear output transformer can be wired as triode, ultralinear or true pentode, although pentode operation requires a regulated screen-grid supply to work right.
Speaker builders think they can approach speaker design the same way: with swapping drivers and moving stuff around and making things smaller or bigger and playing with crossover slopes. Unfortunately, speakers aren’t as easy as that. On paper you can make drivers work together with a given crossover, but that’s just the electrical part of it. Once you stuff all those goodies in a box, it gets exponentially more difficult to make things work. Phono cartridges are even harder. If you think you are technically competent, just order some parts and put a cartridge together. In the end, a successful designer has to deal with physics, mechanics, passive filter design, mating with an amplifier of unknown electrical characteristics, and practical considerations like finish, reliability and trying to make a profit. Or not lose money as the case often is.
Though all speakers are flawed, there are certain starting points that seem natural: moderate to high efficiency, a three-way so to avoid a crossover in the most critical band and there are umpteen-hundred different ways of designing a three-way speaker, enclosures large enough to put the drivers at ear level without stands, and ability to play at high levels without stress. Ha! What a set of requirements! The road to audio perdition is strewn with aweful sounding three-ways, in large boxes, that are moderately efficient and sound like crap. That’s why some of us gravitate to 2-ways and full-range designs. So why not a single-driver then?
Most high-efficiency, single-driver systems are disappointing because of limitations in range and volume. If they do play high and low, they quickly fall apart when you throw Wagner or Ellington their way. The closest to succeeding have been field-coil drivers in really big horns. A horn loaded driver’s useable frequency range is dramatically extended while the loading of the horn helps to dampen out cone resonance. There are still limitations, even with the best horn designs. A driver large enough to do decent bass in a full-range horn will also beam and roll off in the highs. The result is darkness, interrupted with bright splashes, and a narrow soundstage, which works nicely with mono recordings where the center image is all important and where the original recordings were rolled off.
The pioneers of speaker building discovered all of these limitations back when they were using field coils, SEDHT amps and horns. They enjoyed success because the recordings were limited and expectations were not so high. When “hi-fi” arrived with the advent of the LP, the greater awareness of frequency response and extension and just how bad contemporary speakers were, led to wide adoption of 2-way, then 3-way designs. The ultimates were the Patricians, Hartsfields and Bozaks. But when stereo arrived, the budget and space for speakers were effectively cut in half. The drive for affordable and compact speakers led to more complex crossovers that had to cover up for driver and box problems. Drivers were designed to quickly roll off so they integrated better with the other drivers; it’s like using a vacuum tube that only amplifies in the bass, then quickly rolls off causing all kinds of phase problems. It gave us a collection of poorly performing drivers with an overly complex crossover, housed in a cheap box, and requiring ever more powerful and complex amps to overcome the crossover, giving us confused and distorted sound. It’s no surprise then that we had a single-driver renaissance.
If It Works, Don’t Fix It
So, we’ve come full circle, back where we were 70 years ago, with single-drivers in huge boxes, with a series of limitations that are asking for a nuanced fix. I say nuanced because you want to keep the strengths of the single driver and somehow extend the range of the speaker. Better speaker designers use the natural roll-off of drivers as part or entirely of the crossover design, not as some kind of problem to be fixed with an elaborate crossover design. Over the years, the idea has led to more efficient and more natural sounding speakers, keeping in mind that good chokes and capacitors cost money. This method of designing requires good taste and pragmatism as much as computer programs, test equipment, and theory books.
At recent shows, I’ve been seeing more use of full-range drivers with tweeter and woofer augmentation, but most of those had the tweeter and woofer crossover points too close to the full-range driver, thus stepping on its toes. One of the few designers getting it right is Jim Jordan of Vaughn Loudspeakers.
After hearing his room at the 2009 RMAF, I asked for a review sample. The sound of the Vaughn Loudspeakers room was full range, but with the midrange purity and magic of full-range driver systems. Without any whizzer cone distortion, or horn honk, these had detail, transparency, power and good frequency extension. Also, it was putting out plenty of sound with a single-ended amp from Wavelength. I thought that these might be an answer to one of my unanswered questions: is there a speaker with 9 octaves of range, efficient enough to drive with a few watts, and that play loud with grace? Is there a speaker that can reproduce Starker and AC/DC? Mozart to mayhem? But first, some numbers: 5-inch ribbon tweeter, 8-inch Fostex full-range, 8-inch rear-mounted passive radiator, 12-inch woofer with a second 12-inch passive, 97dB efficient at 8 ohms, 37 to 40k Hz.
What we have here, then, is a pragmatic attempt at solving a problem that has kept many traditional audiophiles away from low-powered amps and single-driver speakers. Instead of a huge and usually ugly horn, we have a “normal” sized box that performs as well as many horns but is more affordable and is prettier to look at. Honestly, there are some cost-no-object horns that are downright funny looking. I don’t like being distracted by mirrors and bright colors. The classy finish and average size of the Zinfandels allows me to concentrate on the music.
Of the full-range-drivers-with-ribbons-added, most have been somewhat bright and ugly. Perhaps the problem was the reliance on computer models, published specs and test equipment. I’ve helped with voicing a full-range/ribbon combination, and the best results were with the crossover point two octaves higher up, where it doesn’t comb filter against the main driver creating peaks and dips, and peaks are more bothersome than dips. Computer models are relatively simple, especially those that run on a desk-top PC. Jim does use a choke on the full-range driver to get rid of a midrange peak. It does not have a capacitor to roll off the bottom. The ribbon has one capacitor to gradually introduce the highs for a good blend. That’s one choke on the full-range and one capacitor on the ribbon.
Give an Inch, Take a Mile
Regardless of marketing hyperbole, there will never be a single dynamic cone that can do full frequency range recordings (outside of headphones), and that goes for whatever box you want to try. I’ve heard exotic attempts to overcome the limitations, and short of jumping to a parallel universe that doesn’t have the same laws and limitations, it’s never going to happen. Just remember that phono cartridges have difficulty reproducing music with heavy bass and treble content at the same time, and remember that the moving mass of a phono cartridge is almost nothing compared to a dynamic driver. Let’s not forget that some electronics have difficulty putting out the same power at 15 Hz and 15kHz as at 1.5kHz. Making all this work perfectly is almost impossible because designers have yet to overcome the limitations of cartridges, transformers, speakers and all the rest. So, the intelligent, successful designers must make some concessions to reality. This is the case for Vaughn Loudspeakers: a blend of idealism and pragmatism (pragmatic idealist or realist?). Tasteful use of ribbons, woofers and passive radiators to let you hear all the music, while the Fostex is left to make midrange magic.
First listening was promising, but the balance was dark and wooly. Male voices had too much prominence and females had too much chest-tone. It was nothing like what I heard in Jim’s room. The first thing to do in this case was experiment with positioning, and these have a wrinkle. Because there are bass drivers on all four sides, including the full-range driver although it’s more of a midrange with heft, small movements made dramatic changes: it’s down to inches. The woofers firing toward the center are higher than those on the outside firing outwards. If you are coupling too much, you can swap the channels because the bass will sound different. Therefore, positioning is very critical for balanced bass. Too close to a boundary and the bass gets boomy. I went from thick and wooly to a balanced sound by a total of eight inches, both moving out from the wall by two inches and away from the side walls by two inches (2+2+2+2=8). Also, since there are drivers on all four sides, moderate toe-in changes bass response. If you find the best bass coupling near a wall or corner, toe-in will change the way the bass driver is coupled to the room. Rather than being a design flaw or a problem, this arrangement adds flexibility. In a large room that needs more bass reinforcement, you should have enough flexibility to find a sweet spot. Swap channels; change toe-in. If the bass is too thick or thin, try repositioning before blaming cables or amps. Though not simple to situate, the flexibility allows adaptation into a greater variety of room shapes and sizes.
These are not overly picky. I ran some radically different amps and if the amp had low distortion, the results were pleasant. The Zinfandels are honest with bad material, poorly adjusted cartridges, and/or electronic distortion; cover up sins, they do not. In this way, they are similar to classic high-efficiency horns. On the other hand, the Zinfandels don’t have any ugly sound of their own, like classic horns. You still know you are listening to a Klipschorn when you have a 5-watt SEDHT. With the Zinfandels, there isn’t a shouty/aggressive quality to overcome with soft/dark sounding electronics, or cables or cartridges, etc.. When switching from a modified, restored Eico HF-87 to a large transistor amp, I could hear the texture of the sound change, going from something like caramel to dark cooking chocolate. The results are close to “garbage-in-garbage-out”, which is the goal for intelligent designers and listeners.
Honesty offends some listeners. If you have bad sounding material, and there aren’t better pressings, don’t punish your good recordings by dumbing-down the system to make the junk sound acceptable. Rather, find yourself a second turntable and a classic moving iron or moving magnet cartridge, load it “wrong”, and run it into a “classic tube sound” phono stage. Run good equipment with the Zinfandels and you are rewarded.
Fragility is not a concern with the Zinfandels. While reviewing the Feastrex drivers, I was always concerned about damaging something so expensive and with limited availability. I’m not saying the Fostex is cheap or that I am encouraging you to set them on fire. They can rock, if you want to rock. I didn’t hear the Fostex go berserk or break-up with aggressive pop music (though I did hear something-see below). While being able to do much of what a single-driver speaker can do, they go where single-drivers can’t: louder. As volume increases, a full-range driver’s frequency response gets exponentially worse. A full-range loses high and low extension as it struggles to do tiny movements on top of big movements. Because the Fostex driver isn’t horn loaded, the driver rolls off quicker and you have less change in tonality with increased volume. Couple that with a ribbon and the dedicated bass drivers, and there isn’t the impending-sound-of-doom of pushing a single driver to play big-band, heavy-metal, big orchestral, or anything outside of the boring-audiophile-approved-chanteuse-recordings segment. The designer lets the Fostex do what comes naturally, and helps it where it needs help. The extended range from horn loading is a good thing, but you still aren’t getting one horn and one driver to do everything.
A Bigger Record Collection
I found myself listening to a greater variety of jazz, blues and classical with the Zinfandels. The attractive midrange coming from the Fostex made it easier to emotionally engage a recording. Music that was ‘boring’ with my regular speakers, seemed more alive. There is the emotional involvement that the single-driver fraternity craves, but with the extra range. Just like the good full-range-driver designs, vocals were pleasing. It was easier to decipher lyrics and to hear details in the background. Getting the crossover out of the music works wonders. I enjoyed a larger portion of my record collection, which is a selling point.
The blend between Fostex and ribbon was inaudible at reasonable levels. With orchestral music, plus wind symphony and big band, the sound of the winds was pretty darned fantastic. Growing up around concert bands and jazz bands, I have a Goldilocks appreciation for the texture of winds, and when they are reproduced “just right”. The overtones that go missing with a full-range were there and in the right proportions. Similarly, and particularly telling, cymbals never sounded like compressed air. They took on a darker bronze quality, like miniature gongs or tam-tams, which I think is more truthful. There is an incredible array of cymbals out there—big, small, bright, dark, you name it.
As I said up top, the bass can be adjusted to blend with your room. When properly situated, bass is still slightly warm, but not bloated or slow. Roll-off occurs fairly high up for a speaker this size. The 37Hz to 40KHz figure quoted in the marketing does not tell me if this is the -3dB point, but it’s probably the truth. I could hear/feel the bass start to roll off in the low 40Hz range. By 20Hz, the response is down far enough that the Zinfandels might not be the best choice for big fans of organ music, though a true subwoofer should be able to blend with the Zinfandels. The bass is very tuneful and well connected to midrange and highs. String bass and piano have overtones that make the low notes a full-range experience, as they are in real life.
The fly in the ointment is that since the full-range driver is still trying to do almost everything, an audible amount of intermodulation distortion rears its head when you start cranking things up. While the ribbon and bass drivers are still loafing, the full-range is working pretty hard. Now, understand that I was really cranking it up with one of my favorite Jimmy Smith records, Organ Grinder Swing, a great record with Kenny Burrell and Grady Tate. The sound is fantastic and features a heavy dose of Hammond bass (Japanese Verve reissue). When I got it to the point that Jimmy’s Leslie was in the room, the Fostex waived the white flag. To be fair, this was in a 23’ by 17’ room with 10’ ceilings, with a 200wpc class A transistor amp. So is the criticism fair? Only as a caution to any headbangers who might get the idea that this is great for Insane Clown Posse or Metallica. Led Zep though? Page’s guitar sounded fabulous. With a smaller room (most will be), and smaller amp (most will be tube and well under 35wpc), the Zinfandels can handle most anything thrown its way. In a smaller room, I would bet that the extra room gain in the low bass plus the smaller dimensions would make any music accessible.
Like some full-range single-driver designs I am familiar with, the Vaughn Zinfandel’s imaging was very good. From within the speakers, around the speakers, behind and in front, imaging was excellent. I’m beginning to believe that full-range drivers have a leg-up on other designs. Regardless of my picayunes with full-range units, the absence of a crossover in the most sensitive range of our hearing pays dividends.
Rhythm was good, though not great. With so many bass drivers, placed in different planes, bass slam and attack was softer than much of the single-driver competition, especially those loaded with a horn. On the other hand, the Zinfandels go lower and the roll-off is more gradual. Further up, where the Fostex dominates, attacks are quick and clean. Strings, mallets and percussion are cleanly reproduced. Speed is well above average as you transition from Fostex to ribbon.
Tasty
What niche does this speaker fill? Where is its place? In contrast to most high-efficiency speakers, and most single-driver speakers, these are flexible with amplification, forgiving of some amount of shortcomings, and are a good fit for medium-sized rooms. Also, instead of having to use room boundaries for bass reinforcement, the speaker does well in traditional speaker positions (positions for best imaging). Horns that require corner or wall loading can be too far apart to properly image in some rooms.
My old favorite speakers, like Vandersteen and Magnepan, are easy enough to drive for a 60wpc amp, but are horrible matches for lower powered amps, especially single-ended ones. There is magic in the simplicity of the no-feedback, transformer-coupled, directly-heated, single-ended, class-A triode amp, but only if you have an appropriate speaker. There are efficient horns that work, such as the classic horns of the past, but most of those have honk and glare. The high-end horns that are smooth and full-range, happen to cost a lot of money. Some push three figures.
The Zinfandel’s frequency response, though much better than many single-driver speakers, has some excess warmth and tails off quickly below 30 Hz. Whether you will hear the warmth, or miss the subterranean bass depth, depends mostly on your taste in music. Integration of the ribbon and full-range eliminates my biggest complaint about single-driver speakers: these have the high frequency extension needed to reproduce overtones. Those overtones, and their presence in the correct proportions, are the characteristic aural fingerprint of an instrument or voice. Even stringed basses, tubas, contra-bassoons, etc, have complex overtones that require good high frequency extension. The highs are actually better than most traditional two and three way speakers, with very little of the change in tonal quality between a tweeter and bass/mid. There isn’t the glare, peaks, squawks, and thin bass of many horn designs. The tonal balance resembles a classic 3-way designs, but without the penalty of complicated crossovers.
The Zinfandel is attractive, low-distortion, wide-range, efficient and a better deal than many competing models with boxes the size of refrigerators. It’s enough speaker for me, and I listen to just about every genre of music. Had I not already purchased a cartridge and a new set of line-sources, I would probably have chiseled away at Jim for a good deal. I even prefer them to my old trusty Maggies on a large percentage of recordings, because big panels aren’t perfect. One thing I’ve noticed about many single-driver adherents is their use of CD digital and rather limited repertoires, including some dreaded audiophile junk—the reason I dread going to shows. If all you listen to is boring female vocals, played back on a CD player, then a limited speaker might be for you. Diana Krall won’t challenge any decent system. If you like the purity of SE-DHT amps and full-range drivers, but like real music, then try these. It gets you close to having your cake and eating it too, or marrying a super-model who is smart and rich (that would be even more difficult than a good speaker).
Manufacturer’s Comment:
I have two explanations of our design choices I would like to make.
1. Concerning the dynamic capabilities of the Zinfandel playing big music in big rooms with large amplifiers. The full-range Fostex driver in the Zinfandel is not rolled off on the bottom-end which allows it to cover the range of 85Hz – 7000Hz. We tried rolling out the bottom-end of the Fostex but the loss of transparency and coherence by adding crossover parts and having two drivers operating in the critical upper bass lower midrange area was not worth the increased ability to play louder. The Zinfandel should meet the loudness requirements of most audiophiles but Phillip’s warning to “head bangers” or those looking at playing big music, very loudly, in large rooms is spot on. The Zinfandel is not the best choice for those listening purposes.
2. Low Bass response: Our design goal for the Zinfandel was to make a near full-range speaker system in a room friendly package. Generally, high-efficiency drivers give up low bass response to gain higher efficiency. To get really low bass from high efficiency designs normally requires larger drivers and cabinets or even larger horn loaded bass systems. The Zinfandel was designed to easily work into most home listening environments so we wanted to keep it at a reasonable size. For this we gave up the very lowest octave which can be more easily integrated into a variety of environments with a powered subwoofer. The Zinfandels are voiced full and rich with response down to the mid 30Hz range which should provide sufficient musical enjoyment for most listeners and various types of music; but if not, the Zinfandel’s will easily mate with a high quality sub.
Again, I would like to thank Phillip and Dagogo for the opportunity to let more people know of our unique speaker systems. The time and effort put into this wonderful review is sincerely appreciated, I can not thank you enough!
Thanks, Jim
Jim Jordan
Vaughn Loudspeakers
www.vaughnloudspeakers.com
- (Page 1 of 1)
