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Perhaps you've already noted some inconsistencies in Mr. Belt's theses. First, he attributes adverse properties to the electromagnetic radiations from the AC supply, which are alternating in polarity, then he purports to cure them by devices which are supposed to provide a countering "charge," which would have to be DC, and would, if we take him literally, be electrostatic rather than magnetic. He claims these radiations act upon our own perceptions, but applies his treatments to the equipment instead. And he claims that the effect of his charged "electret brush" can be reversed by changing…
Another piece of the softening was the Airfoils' handling of dynamic transients, which simply weren't as large or precise as with the best speakers I've heard. Introduction and Fandango is a scorching flamenco-style piece. With most speakers, the transients will positively explode, the notes starting and stopping in a sharp transient that impresses a kind of aftershock into the air. With the Airfoils, the explosions just weren't there.
"In the Mood," from The Carnegie Hall Jazz Band (CD, Blue Note 36728), was another good example of the Airfoils' slightly soft perspective. The trumpets…
Sidebar 1: Paul Paddock on the Airfoil Bending Wave Driver
It's rare to find a truly new speaker technology, so I couldn't help but be intrigued by the Airfoil's Bending Wave Drivers. I asked designer Paul Paddock how they work.
"They fall into the class of devices called 'Traveling Wave' drivers. Basically, you're setting up a shock wave with a linear voice-coil along one edge of the diaphragm, that ripples through the membrane."
"So you're setting up a longitudinal wave in the membrane, and as it propagates along the membrane, transverse waves are given off and create…
Sidebar 2: Specifications
Description: Five-piece, three-way, loudspeaker system with powered subwoofers. Drive-units and configurations, per channel: Main unit: 9 Airfoil Bending Wave Drivers stacked vertically in line-source array, two 6.5" polymer-cone Coupling Woofers in sealed enclosure at base of line-source tower. Subwoofer: two 12" doped paper-cone woofers in Balanced Force Compression Design (back to back) in freestanding cabinet. Passive crossover, coupling woofers to towers: 170Hz passive first-order, two-way series network. Active crossover, subwoofers to main units: 80Hz low…
Sidebar 3: Associated Equipment
Analog source: VPI TNT Mk.V-HR turntable, Grado Signature Reference cartridge.
Digital sources: Simaudio Moon Eclipse, Wadia 861 CD players.
Preamplifier: VAC CPA1 Mk.III.
Power amplifiers: VAC Renaissance 70/70, VTL Ichiban, Mark Levinson No.20.6, Classé CAM-350.
Cables: Interconnect: Nirvana S-X Ltd. Speaker: Nordost Valhalla. AC: Synergistic Research and Reference Master Couplers, AudioPrism.
Accessories: MIT Z-System, Z-Center and Nirvana AC systems, AudioPrism Noise Sniffer AC analyzer and Quietline filters; VPI 16.5 record-cleaner,…
Sidebar 4: Measurements
Given the Airfoil 5.2 system's bulk, it made sense to take advantage of a road trip I was making through the Southwest last fall to measure the speaker in Brian Damkroger's Albuquerque listening room. The advantage of this was that I could actually get a handle on the speaker's in-room behavior, which its unusual design made imperative. The disadvantage was that I couldn't take all the measurements that I usually do in my Brooklyn test lab. (Because of my need to keep my traveling rig as portable as possible, I used the Mitey Mike II from Joe D'Appolito rather…
FRANCK: Violin Sonata in A
RACHMANINOFF: Cello Sonata in g
Renaud Capuçon, violin; Gautier Capuçon, cello; Alexandre Gurning, Lilya Zilberstein, piano
EMI Classics 5 57505 2 (CD). 2003. Carlo Piccardi, prod.; Ulrich Ruscher, eng. DDD. TT: 65:33
Performance ****
Sonics ****
RACHMANINOFF: Cello Sonata in g
Renaud Capuçon, violin; Gautier Capuçon, cello; Alexandre Gurning, Lilya Zilberstein, piano
EMI Classics 5 57505 2 (CD). 2003. Carlo Piccardi, prod.; Ulrich Ruscher, eng. DDD. TT: 65:33
Performance ****
Sonics ****
Bold in sound and sensibility, this live-wire recording matches two Romantic chamber works related in spirit in performances by two young soloists related by blood. In their early 20s, the frères Capuçon are a pair of highly touted string players; most notably, the Frenchmen are championed by Martha…
"Uhh! What is it?" I was being prodded on the arm. Admittedly it was gentle, almost polite prodding, but prodding it still was, a rude disturbance of the cocoon I had woven around myself in seat 31J of the American Airlines MD-11 winging its way across the North Atlantic. I pushed Pause on the Discman, insensitively not waiting for an opportune cadence in the Brahms Piano Quintet that had been my erstwhile virtual reality.
It was a flight attendant. "You're annoying the other passengers," she said, "Your stereo is way too loud."
I was embarrassed, of course. I was also…
The DC supply voltage is smoothed with a 100µF electrolytic, then fed to an encapsulated module that converts it to the ±5V-and-ground supply required by the active circuitry. (This 100mA-capable DC/DC converter is said to be the most expensive single part used in the amplifier.) The front or base of the "U" carries the ¼" headphone jack, the front-panel switches, and the volume control, the last a conductive-plastic component from Clarostat. The other leg of the "U" carries a handful of resistors, 100µF supply capacitors, and the heart of the amplifier: a largish, 24-pin module that…
Well, used as a simple amplifier, the HeadRoom stomped all over the Advent. The AC-powered receiver's bass sounded lumpy and spongy compared with the little battery-powered amplifier. This was probably due to the Advent not having a true headphone output, instead padding down its speaker-level outputs with series resistors. But it sounded so grainy in the highs compared with the HeadRoom that I ultimately ruled it out of contention.
The Denon CD player, on the other hand, has a surprisingly good headphone output, capable of driving Sennheiser '580s to moderately high levels without…