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Determining a pair of headphones' optimal frequency response is neither obvious nor trivial (see www.stereophile.com/features/808head, footnote 1). The only parameter of headphones that I measure, therefore, is their electrical impedance, to determine how difficult they are to drive. To take this reading, I inserted the JH16 Pros in my ears so that they had the correct acoustic loading.

The JH16 Pros' impedance and electrical phase are shown in fig.1. The impedance is lower than the specified 18 ohms below 800Hz, averaging 13 ohms in the lower midrange and…

That remains literally true: The 7" full-range drivers to which I'm listening today are from a German company called Voxativ; the horn-loaded cabinets from which they play were also designed by Voxativ, and are made in Germany by the Wilhelm Schimmel piano company. And, with all due respect to Lowther, the 75-year-old English loudspeaker firm that…

Thus did the Ampeggio come about: a twice-folded horn, nearly 9' from throat to mouth, that's intended to amplify the driver's rear wave—and because all such horns act as acoustical low-pass filters, the real objective is to maximize in-room bass extension. The Voxativ driver's high excursion was one boon to the design effort; another was an unexpected source of engineering inspiration: "I had the idea to optimize [the canine's…

Description: Single-driver, hornloaded, floorstanding loudspeaker. Frequency range: 38Hz–20kHz. Impedance: not specified; measured impedance >10 ohms. Sensitivity: 98dB/2.83V/m.
Dimensions: 47" (1100mm) H by 19" (350mm) D by 425" (400mm) W, Weight: 121 lbs (55kg).
Finishes: piano gloss black and white.
Price: $29,750/pair.
Manufacturer: Voxativ GmbH, Nollendorfstrasse 11a, 10777 Berlin, Germany. Tel: (49) (0)30-2100-5662. Web: www.voxativ.com. US distributor: Audio Arts, Inc., 1 Astor Place, Suite 11(h), New York, NY 10003. Tel: (212) 260-…

Analog Sources: Garrard 301, Thorens TD 124 Mk.II, turntables; EMT 997, Schick tonearm; Ortofon SPU & 90th Anniversary SPU.
Digital Sources: Wavelength Cosecant, Furutech GT40, Ayre Acoustics QB-9 USB D/A converters; Apple iMac G5 computer running Apple iTunes V.10.1 & Decibel V.1.0.2 playback software; Sony SCD-777ES SACD/CD player.
Preamplification: Auditorium 23 Standard/SPU & Hommage T1, Silvercore One-to-Ten step-up transformers; Shindo Masseto and Shindo Vosne-Romanee preamplifiers.
Power Amplifiers: Shindo Corton-Charlemagne…

A highlight of the two audio shows I attended this past spring, SSI in Montreal and Axpona in Atlanta, was listening to the Voxativ by Schimmel Pianos Ampeggio loudspeaker. At first sight it looked like yet another rear-loaded horn using a Lowther driver, albeit with a superb level of finish—but on first listen it was obviously not a Lowther-based design, having none of the Lowther "quack." So when Art Dudley told me that he had a pair of Ampeggios in residence to review for this issue's "Listening" column, I resolved to drive upstate, give a listen in his room,…

Voxativ Ampeggio Impedance Peaks #1
Editor: Horn loudspeakers was my main subject as B.Sc.E.E. in 1980. . . Ideally a sound should travel from the diaphragm through a horn and into the air without any sound reflected, and traveling back to the diaphragm. A sudden change in the horn shape will cause a sudden change in acoustic impedance, and sound will travel back to the diaphragm. The end of the horn wall, at the mouth, does make such a sudden change. But if the mouth is large compared to the wavelength, the acoustic impedance has almost changed to that of free air, and the…

The September 2011 issue of Stereophile is now on newsstands. On the cover, we feature Oppo’s latest universal disc player, the BDP-95: It slices, it dices, it plays everything and sounds great. In his review, Kal Rubinson installs the BDP-95 in his Manhattan apartment where he compares its two-channel output against that of the Sony SCD-XA5400ES, then he takes the Oppo to his Connecticut home and compares its analog multichannel output against that of Oppo’s earlier BDP-83SE. He comes up with some interesting conclusions.

Also in this issue:

Erick Lichte listens to the…

Cut Copy is one of the girls’ favorite bands, a band Natalie had requested during my DJ set at her birthday party, so we are sure to have a good time.

There’s something in the air tonight
A feeling that…