April 15, 2010

Van Zyl Audio Frontline Loudspeakers

We’re so used to passive crossover networks in our speaker systems that we tend to forget how much they can degrade the sound. So why don’t designers use full-range drivers and thus avoid crossovers altogether? Mostly because there’s no such thing as a genuinely full-range driver. To get the wide frequency response most audiophiles demand from our speakers, we’re pretty much stuck with crossovers. But even if crossovers are necessary evils, there are still some things that can be done to minimize their deleterious effects on the sound.

One such thing is to keep the crossover frequencies out of the midrange, where the ear is most sensitive, by using for that region a wide-range driver, and crossing over from that driver to the tweeter at as high a frequency as is feasible. With such a loudspeaker, the audio signal is sent directly from the amplifier to the midrange/bass driver, before it even "sees" the crossover -- thus, any sonic degradations caused by the crossover’s own inductors, capacitors, and resistors are kept out of the midrange. A simple high-pass crossover is used on the tweeter.

This is the technique used in Van Zyl Audio’s Frontline loudspeaker. Company president Johan van Zyl designed my Affirm Audio Luminations -- massive horn speakers that use a single, very expensive 5" Feastrex Monster alnico driver. Thanks to van Zyl’s tractrix horn enclosure, the Feastrex driver actually produces decent output down to the middle of the 40-50Hz range. No other horn design I’ve heard comes remotely close -- so when I ran across the Van Zyl Audio Frontlines at the Dallas Audio Fest, I immediately suggested to VZA that I review them.

Johan van Zyl believes that a good speaker has three characteristics: fast transient response, which enables it to accurately track fast, complex waveforms; dynamic realism, which enables it to accurately track all volume changes, small and large; and, when no music is playing, silence. If a speaker can’t accurately track transients and dynamics, it will produce an output unrelated to the music -- in a word, noise.

Describing

Because a pair of Frontline speakers sells for only $7000 USD in its standard Formica finish, Van Zyl Audio can’t afford to use Feastrex drivers, one of which costs more than a single Frontline. Instead, van Zyl uses the popular Jordan JX92S driver ($180), a single 5.5" (140mm) metal cone. The nearly full-range Jordan rolls off above 10kHz. To cover the highest octave, 10-20kHz, van Zyl crosses over the Jordan to an Aurum Cantus G2Si ribbon tweeter, using a first-order crossover at 21.5kHz. That means there’s just a single capacitor on the tweeter and no coil or low-pass crossover on the mid/woofer, which means that the latter is run full-range. Of course, you may be skeptical that a 5.5" driver with an actual radiating diameter of only 3.25" could possibly produce any bass whatsoever; after all, most midrange drivers are bigger than that.

The Jordan driver has a reputation for ringing (i.e., a tendency to vibrate at a frequency unrelated to the musical signal), so van Zyl tries to control the driver in two ways. First, he uses a rear-loaded horn to acoustically load the driver over its full frequency range. Second, van Zyl uses some proprietary methods to damp the ringing. Additionally, for better dynamic control of the driver, he connects it directly to the amplifier, with no crossover between them. Typically, I’m told, a coil like those found in most crossovers will reduce an amp’s damping factor by 50%. The higher the damping factor, the better the amplifier can control the driver.

In my view, what really makes the Frontline work is the enclosure. Looking like an Affirm Audio Lumination with its top 14" lopped off, the Frontline is still an imposing speaker, measuring 48.81"H x 14.5"W x 27.25"D. However, the Frontline’s sloped rear panel means that, at the top, it’s only 11.56" deep. Except for that rear panel, the enclosure walls are vertical. The Frontline weighs 125 pounds, and even more when its internal cavities are filled with sand. With a claimed driver sensitivity of 88dB, the Frontline isn’t as efficient as many horn speakers. Some horn enclosures load their drivers only in the bass, filtering out the midrange and treble frequencies; but the Frontlines’ throat-loaded tractrix horn loads the Jordan driver up to 1kHz. The mouth of the horn is at the bottom of the enclosure, and it radiates omnidirectionally from there. Most horns promise good bass, but I have yet to encounter any other that produces the quantity and quality of bass of van Zyl’s horns. With a nominal impedance of 6 ohms, the Jordans actually drop to 5 ohms over much of the midrange. If you drive them with a tube amp, use the amp’s 4-ohm taps.

Several visitors commented favorably on the Frontline’s Formica finish -- a remarkably realistic likeness of a beautiful walnut-burl veneer. It’s also available in a wide assortment of custom Formica veneers (add $200/pair), domestic real-wood veneers (add $500/pair), or exotic wood veneers (call for quote).

Arranging

Johan van Zyl delivered the Frontlines to my listening room, where he went through a finicky process of precise positioning. Placement was critical with the Frontlines: too close to the front wall and they sounded hooded, with the dreaded "cupped-hands" coloration; too far out into the room and they sounded thin.

With a driver sensitivity of only 88dB, the Frontline doesn’t encourage the use of low-powered amplifiers, but that didn’t stop me from trying. As it’s my amplifier of choice for my Affirm Luminations, I had to see if my Art Audio PX-25, a 6Wpc single-ended-triode (SET) amplifier, could drive the Frontlines. The PX-25 easily drives the 103dB-sensitive Affirms, but while it sounded divine with the Frontlines at low levels, it ran out of steam on climaxes. So out went the PX-25 and in went my Audio Research VS115, a 120Wpc tube amp, connected via its 4-ohm taps.

I tried two sets of speaker cables, Clarity Cables’ Organic and Audience’s Au24 e; both are excellent, but with different sonic signatures. I finally settled on the Audiences -- their high-frequency performance sounded smoother with the Frontlines, and the extra-large spades I specified when I ordered them perfectly fit the Frontlines’ huge binding posts.

The Frontlines’ drivers had been broken in already, but not the binding posts and wiring. The sound seemed to stabilize after 100+ hours of play, and I began my critical listening.

Listening

In my 23’L by 20’W by 12’H room, the VZAs’ bass was deep and powerful enough to reproduce most music very satisfactorily. There was plenty of weight and impact -- no wimpy bass here. It didn’t flex my windows or liquefy my internal organs, but for most acoustic music, the bass was surprisingly good. If the Frontlines’ 5.5" drivers hadn’t been visible and I hadn’t known what I was listening to, I might have guessed I was hearing good 8" woofers.

But the quality of bass is as important as its quantity. Because the Frontline uses a single driver for the bass, midbass, midrange, and most of the treble, all of these ranges spoke with the same voice. The small, light Jordan cone was very fast, and the horn loading ensured that the cone didn’t have to move too far, so bass transients and details were just superb. If you want deeper bass, consider a subwoofer; I tried the Frontlines with two of JL Audio’s Fathom f110 subs and got a good match, with high-impact bass flat down to almost 20Hz.

In Telarc’s SACD transfer of its very first digital recording, released on LP (Telarc 5038) in 1978, years before the birth of the Compact Disc, director Frederick Fennell, who loved percussion instruments, nearly turns Gustav Holst’s lovely Suites 1 and 2 for Military Band into drum concertos (SACD, Telarc SACD-60639). This recording with the Cleveland Symphonic Winds introduced the world to the famous Telarc bass drum, whose stygian depths made it compulsory demonstration material at hi-fi shows everywhere. The Frontlines delivered surprisingly deep, powerful bass-drum whacks that had me worried I might have to dodge cone-shaped projectiles flying across the room. No fooling -- I’ve heard 8" woofers that didn’t do as well with this recording . . . and, to be fair, some that do better.

The other area you may be curious about is the treble. Here’s the display of my real-time analyzer with the microphone at my listening position; you can see that the treble extends up to 20kHz in-room, though not linearly.

The Frontline’s treble was extended, with the sweet, nonaggressive character I associate with ribbon tweeters. Although there was a dip in the response curve where the Jordan cone crosses over to the Aurum Cantus ribbon, the treble still had plenty of detail and sparkle. When I played "PercusienFa," the first cut of Erik Mongrain’s Fates (CD, Prophase Music MVDA4585), I heard more guitar overtones than I’m accustomed to, and it was here that I fancied I could hear just a smidgen of ringing from the Jordan. Usually it was well controlled, but apparently, Mongrain’s aggressive recording possesses so much energy at just the right frequencies that it overloads the normally effective damping.

The midrange exhibited all the detail and dynamics you’d expect from a small, light cone. Pepe Romero’s Flamenco (CD, Philips 422 069-2), remastered by First Impression Music for one of their spectacular K2 reissues (CD, First Impression LIMK2HD 022), is an amazing recording of a flamenco concert, with singer, guitar, and male and female dancers. All of these participants were realistically recorded, but the most startling was dancer Paco Romero. His foot stomps, a prominent part of the art of flamenco, were brutally dynamic, exploding from the speakers with enough force to frighten the unwary listener. The Frontlines captured all the detail of Paco Romero’s footwork, so inhumanly fast that you suspect he has four feet.

Rebecca Pidgeon’s The Raven has been an audiophile favorite since its 1994 release on CD as Chesky JD115, though I’ve always wondered if the photo of Pidgeon on the cover hasn’t sold as many copies as the music. I’m not saying that’s why I bought it, but I’m not denying it, either. So when I learned that the original recording engineer, Bob Katz, had remastered The Raven for 24-bit/88kHz download from the Chesky brothers’ www.HDtracks.com, I couldn’t resist. On the album’s best-known track, "Spanish Harlem," Pidgeon’s delivery was delicate and pristine, enhanced by a pitch-black background. The Frontlines captured the performance’s exquisite detail without stripping away any of its tonality and warmth. They also clearly conveyed the smoother, less grainy sound of the higher-resolution remastering.

Soundstaging was another strength of the Frontlines. During the review period, I had on loan a rather expensive digital source: a Mark Levinson No.512 SACD/CD player ($12,000). I played an SACD through my Sony SCD-XA5400ES SACD/CD player and noted its spacious if slightly dark sound. When I switched to the Levinson, the first thing I noticed was that the room sound -- that sense of spaciousness I’d just heard through the Sony -- was almost completely absent! The Frontlines made that unambiguously clear.

Another soundstaging observation: The Frontlines were unusually fussy about left/right channel balance. Many recordings that normally sound fine with the balance control at its center, flat position required that the control be adjusted a few clicks to the right or left before I could achieve a believable soundstage. I think that illustrates that the Frontlines revealed more detail about a recording’s soundstage than do most speakers. It also underlines that if you use the Frontlines, your preamp or integrated amp had better have a balance control.

Comparing

Is it fair to compare $28,500/pair and $7000/pair speakers? Probably not -- but I couldn’t resist comparing the two Johan van Zyl designs I had in the house at the same time: the Affirm Audio Lumination and the Van Zyl Audio Frontline.

In the bass, the Frontline actually had slightly more punch than its far more costly older brother, but the Lumination had just a tad more detail. The Affirm’s Feastrex driver, however -- a good part of why it costs so much -- produced a more refined tonal palette and a more elegant, naturally detailed sound. And although the Lumination’s highs didn’t extend as far, they were very smooth, and completely devoid of ringing. The soundstages were about the same size, but seemed more precisely limned by the Luminations. While all were audible, none of these differences was huge; the Frontline exemplified the law of diminishing returns, providing about 85% of the Lumination’s performance for 25% of its cost. I imagine the Frontline’s bass response would make some listeners prefer it to the Lumination, but neither speaker reproduces the bottom octave at all.

Assessing

Van Zyl Audio’s Frontline won’t appeal to everyone. It doesn’t reproduce ultradeep, wall-flexing bass, and it won’t survive the volume levels for the hearing-impaired that some headbangers demand. What the Frontline does do, however, is deliver fast, detailed sound with hard-hitting dynamics and fully developed instrumental color. And even though it won’t pin you to the wall with deep bass, I found its bass quite satisfying with lots of acoustic music. Further, the Frontline’s sound quality is uniformly excellent across its entire frequency range. The tweeter’s crossover at 21.5kHz is above the audioband, so the Frontline is entirely successful at avoiding all audible crossover degradations -- a monumental task that represents considerable design innovation. A power amplifier of medium output (50-100Wpc) should be enough to drive the Frontlines; there are many good-sounding amps in this power range.

The Van Zyl Audio Frontline excelled at most of the things I value in a speaker -- detail, dynamics, soundstaging, tonal accuracy, texture -- while delivering them in a package that looks good and won’t leave your wallet whimpering too loudly. If my description piques your interest, VZA’s 30-day audition period will give you time to try them out in your system.

For me, the Van Zyl Audio Frontline passed the acid test: I could happily live with them for a long while. Very highly recommended.

. . . Vade Forrester
vadef@soundstagenetwork.com

Van Zyl Audio Frontline Loudspeakers
Price: $7000 USD per pair in standard burl Formica finish; $7200/pair in custom Formica finish; $7500/pair in domestic wood veneers (18 to choose from).
Warranty: One year on manufacturing defects. Manufacturer pays shipping for warranty claims.

Van Zyl Audio LLC
902 Mill Spring Drive
Garland, TX 75040
Phone: (972) 740-6317

E-mail: johan@vanzylaudio.com
Website: www.vanzylaudio.com