It’s almost taken for granted these days that most products in high-end audio are not going to produce significant distortion. One exception is tubed gear, but enthusiasts consider second-order harmonics to be pleasing — the “right kind” of distortion, if you will.
Still, today’s speakers and electronics measure pretty well, especially compared with the cheap stuff of yesteryear. So, the question is: If modern distortion measurements generally vary between “really good” and “excellent,” is there anything to be gained by nudging them a little farther right of the decimal?
As I sat in the center seat of room 514 at the Westin O’Hare during AXPONA, the answer radiated into my ears from two handsome, floor-standing speakers.
Gazing at the Acoustic Zen Crescendo Mark IIs ($22,000 a pair), I could picture Steely Dan vocalist Donald Fagan squinting his eyes and contorting his face as he unleashed a quiver-full of sarcastic arrows at an unfaithful lover in “Black Cow,” from the classic Aja.
Fagen’s Jersey sneer — which has always had an endearing bit of Daffy Duck spittle around the edges — was rendered in all its weathered glory. Chuck Rainey’s loping bass, which propels the song, was deep and tuneful, and seemed to pressurize the air in the room in the way you would experience the instrument live.
The horns, meanwhile, had proper bite — again like the real thing — but never became harsh. Victor Feldman’s electric piano (an instrument that can get buried on some speakers) could be followed easily, as could Larry Carlton’s subtle guitar fills.
Overall, the track had an especially “black background,” which enhanced soundstage depth, spatial cues and reverb trails. This allowed each musical instrument to emerge distinctly, but still weave together as a realistic whole.
Acoustic Zen master Robert Lee told me his goal for the Crescendo, introduced in 2006, was to reduce distortion to the vanishing point. He came up with a three-way, five-driver design.
One of his noise-lowering ideas was to use “under-hung” voice coils for the woofers. Under-hung means the voice coil is narrower than what’s usually seen in traditional (or over-hung) drivers, so it never leaves the magnetic gap of the motor assembly.
“Since the driver’s coil is always inside of the gap, it’s under the influence of the magnet across its entire range and its response has less distortion,” Lee explains in a technical paper he gave me.
The principle can be likened to the old grade-school bar magnet experiment.
“With over-hung drivers, the coil travels beyond the gap and causes distortion in its movements, much like the iron filings that are too far away from the influence of a magnet,” Lee said. “The advantage to the under-hung driver is vastly lower distortion since the coil is always under the influence of the magnetic gap and how it is influenced by the incoming signal voltage.”
The technology is not unique to Acoustic Zen. A few other manufacturers use the basic concept, but it is not widespread. This is partly because under-hung drivers can be more expensive than over-hung. Lee has been honing his design for many years.
Lee chose a quasi-ribbon tweeter for the Crescendo, which also offers low distortion and extends the top end past 25kHz. And if you look at the frequency response plot for the speaker, it remains remarkably flat, particularly through the highs.
As if all that weren’t enough, Lee recently decided he could lower the distortion even more. So, he created the Crescendo Mark II.
“I increased the internal bracing, installed bigger magnets and improved the crossover,” he told me.
The result, to my ears, is a speaker with even greater weight, solidity and clarity than its already fine predecessor. The extremely low level of distortion also allows the music to display a sense of ease, which would encourage long listening sessions.
The Crescendos were being driven by show partner Wyred 4 Sound’s electronics. Wyred has been on a tear in the past year, introducing a plethora of new gear.
At AXPONA, the company was showing two special-edition products: the DAC-2v2SE 10th Anniversary digital converter ($4,499) and the SX-1000R monoblock amplifier ($1,799 each).
“On the DAC, we redesigned the digital input board, hand-matched the parts and added a distinctive case,” Wyred market director Tony Holt told me. “The amp has a new input board, Kimber Kable internal wiring and is fully balanced.”
The compact Class D amp packs a wallop — 625 watts into 8 ohms.
That power could be felt in the thumping bottom end on Paul McCartney’s “Silly Love Songs” from Wings at the Speed of Sound. (Yes, it was on my demo disc –don’t judge.) McCartney’s Hofner bass had the same depth and impact as Rainey’s on “Black Cow,” and the ex-Beatle’s vocals were focused and textured.
Most modern Class D amps, I have found, tend to have a smooth presentation. Wyred’s balanced circuitry undoubtedly also helped snuff out any external noise. The result was detailed, dynamic and utterly effortless sound that drew you in, instead of assaulting your ears.
As I left the room, it all made sense — less distortion, more music. This is the kind of system that, with your favorite records, could help you reach a state of audio Zen.