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Tim de Paravicini Page 4

Stereophile: We're looking at a damping factor of only 20, right?

De Paravicini: Yes, well, it may only appear to have a damping factor of 20 but that needs to be clarified. People have latched on to the idea that damping factor is the only important criterion for tight bass.

Now a conventional dynamic speaker is essentially an electric motor in series with an 8 ohm resistor inside that motor—if you measure the voice-coil terminal it measures 8 ohms DC [(footnote 1)]. Now if you put a screwdriver across those two terminals, you have put an infinite damping factor on that…

Tim de Paravicini Page 5

Stereophile: Well, there isn't big money to be made in high-end audio. Especially high-end tube audio.

De Paravicini: That's right. Even in Japan the pace in audio design has slowed down dramatically in the last four or five years. There is a stagnation because of the lack of incentive. There's not enough marketplace demand. I blame a lot of this on the audio magazines. The mighty word is Gospel, and people believe what's in print much more readily than they believe what is verbal. But the words they print have caused more confusion than enlightenment. And they mislead.

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Yamaha NS-1000 Loudspeaker

Every engineer has known for years that, while beryllium has excellent physical qualities for use as a speaker radiator—light weight, rigidity, and a remarkable degree of internal damping—it is not usable as such because it cannot be stamped out like most other materials. It will not stretch, and any attempt to shape it simply causes it to split.

The Japanese Yamaha firm, better known for its successes in motorcycle design than in audio design, has managed to score a First in audio by devising a way of producing speaker domes of beryllium, by depositing the metal on a suitably…

Yamaha NS-1000 Loudspeaker Specifications

Sidebar: Specifications

Description: Three-way loudspeaker system consisting of beryllium-dome mid- and upper-range drivers and a cone-type woofer. Nominal impedance: 8 ohms. Power capacity (signal): 100 watts.
Dimensions: 14.75" W by 26.5" H by 12.75" deep. Weight: 68 lbs each.
Serial numbers of review samples: 10492.
Price: $950/pair.
Manufacturer: Yamaha Electronics Corp., 6660 Orangethorpe Avenue, Buena Park, CA 90620. Tel: (714) 522-9105. Fax: (714) 670-0108. Web: www.yamaha.com.

Genesis II.5 loudspeaker system

Whenever anyone marvels at the enormous Genesis II.5 loudspeakers in my house, I'm quick to tell them that the II.5 is the smallest, least expensive loudspeaker made by Genesis Technologies. In fact, the company makes two larger speaker systems, the $33,000 Genesis II and the $70,000 Genesis I (footnote 1).

Building such ambitious loudspeakers as the Genesis products is a risky proposition. Big loudspeakers often fail miserably—any flaw seems to be magnified by the loudspeaker's lofty aspirations—the bigger they are, the harder they fall. Moreover, the criteria for what…

Genesis II.5 loudspeaker system Page 2

Although the II.5's tweeter looks at first glance like a conventional dome tweeter, the driver is a custom flat-ribbon type designed by Arnie Nudell. This tweeter, used throughout the Genesis line, has a 0.0001"-thick diaphragm on which a conductor has been etched. As with the midrange, the Genesis tweeter is more properly called a planar magnetic driver.

Three tweeters are used in a vertical array to approximate the midrange ribbon's line-source radiation pattern. The top two tweeters roll off at 8kHz, with the bottom tweeter run out past 20kHz. The rear tweeter is wired out of phase (…

Genesis II.5 loudspeaker system Page 3

What's more, the II.5s didn't sound strained, congealed, or flat when pushed hard. Rather, they reproduced the most demanding passages with such ease that it seemed they weren't even being stretched. At no time did the II.5s show any sign of reaching their dynamic limits—even with such very challenging recordings as Pomp and Pipes (Reference RR-58CD) played back at high levels. These loudspeakers were made for full-scale orchestral music played loudly.

The wide dynamic window in which the music could express itself was greatly enhanced by the II.5's bass performance. Until you've heard…

Genesis II.5 loudspeaker system Page 4

The soundstage of the II.5 system was absolutely spectacular—wide, deep, layered, and transparent. In fact, when the II.5s were tweaked just right, and fed by topnotch source components and amplification, they produced the most spectacular soundstaging I've heard from a hi-fi system. The sense of a huge acoustic existing in space before me was so real that I found myself instantly accepting this artificial reality. Some loudspeakers make you work a little to believe their illusion of soundstaging; the II.5s compelled me to believe I had been transported to the original acoustic event. For…

Genesis II.5 loudspeaker system Specifications

Sidebar 1: Specifications

Description: Three-way floorstanding loudspeaker with woofer amplifier. Driver complement: Two servo-driven 12" woofers, one 4' ribbon midrange, four 1" planar tweeters. Impedance: 4 ohms. Sensitivity: 90dB/1W/1m. Frequency response: 20Hz–20kHz ±3dB.
Dimensions: 28½" W by 6' H by 2½" D. Weight: 1250 lbs/pair shipping, 1000 lbs/pair net.
Finish: Brazilian rosewood.
Serial numbers of speakers reviewed: 251006/7.
Woofer amplifier power output: 400W RMS/channel (into 2 ohm load presented by the II.5 woofers).
Amplifier dimensions: 19" W by 41/2" H by…

Genesis II.5 loudspeaker system System

Sidebar 2: System

At the time of writing, I've been using II.5s for the past five months, auditioning them with a variety of equipment. Without question, the best amplifiers for the II.5s were the superb Audio Research VT150 tubed monoblocks (reviewed in Vol.17 No.8). When relieved of driving the woofers, the VT150s could really sing. It was almost as if these products were made for each other: the II.5s were particularly adept at resolving things the VT150s do so well—eg, depth, space, truth in timbre, and layering. After trying solid-state amplifiers, I recommend tubes for the II.5.…