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Listening #39

One should be able to see that things are hopeless and yet be determined to make them otherwise.—F. Scott Fitzgerald

During the years I've written about home audio, there have been one or two seasons when my heart just wasn't in it. This isn't one of them.

I can't remember the last time I was this enthused about tinkering with and listening to my music system. Maybe it's because I had an unusually good summer—my daughter and I attended more bluegrass music festivals than the year before—so for once I'm trudging away from the sunnier months a fully satisfied customer. It might…

Listening #39 Page 2

Ohm's Law predicted as much: Current times resistance equals voltage. Because most electrical grounds exhibit some resistance—and it's interesting to note that the cheap, crappy ground connections on many household receptacle boxes create a lot more resistance than others—the flow of current through a ground lead must create a certain potential. That alone is not the problem; the real trouble comes from having different grounds within a circuit, all exhibiting different potentials. It's that differential that causes current to flow in what is known as a ground loop—and we hear that current…

Listening #35

"It's rather warm in here."
—violinist Mischa Elman, at Jascha Heifetz's Carnegie Hall debut

By the time you read this, the tomato cages will be back in our shed, the electric fans will be back in our basement, and the snow tires may even be back on my Subaru. But today in Cherry Valley the outside temperature is over 90°, with 68% humidity and the kind of low-lying haze that passes for atmosphere in such diverse films as Mad Max, Mad Max 2, and Mad Max 3. And I'm stuck inside, listening to a couple of amplifiers that run so hot they could make Jesus drink gin out of the cat's dish…

Listening #35 Page 2

So it goes with the Solista, which carries on the Viva tradition in every way: single-ended topology, directly heated output triodes, zero feedback, paper-in-oil capacitors, custom-wound transformers—and the same gorgeous metalwork, which manages to appear both organic and high-tech at the same time. (Schembri's architect girlfriend, Joëlle, contributed to the design.)

The Solista is a true integrated amplifier, not just a power amp with a passive front end. It has three active stages altogether: The input signal begins its journey at the potentiometer and, for voltage gain, goes on to a…

Joseph Audio RM7si loudspeaker

Following my review of two high-performance minimonitors last November (footnote 1), I received a letter asking why I recommended a stand-mounted speaker at all when it was possible to buy a floorstanding design with more bass for the same amount of money. Furthermore, the correspondent went on, when you consider that the minimonitor sitting on its stand occupies as much floorspace as the floorstander, it's hard to see why a market for minimonitors exists at all.

Strong arguments, perhaps convincing to some. But floorstanding speakers have their drawbacks, too. It's much harder to…

Joseph Audio RM7si loudspeaker Page 2

The MDF enclosure is filled with pink fiber and is veneered on all six sides. (The first review samples were finished in oak; the second pair in rosewood, a $200/pair option.) The Infinite Slope crossover is hardwired and mounted on the cabinet sidewall. It utilizes polypropylene- and polystyrene-dielectric capacitors with high-value caps bypassed with low-value ones. The important matched Infinite Slope inductors have laminated steel cores. Electrical connection is via twin sets of gold-plated binding posts, to allow for bi-wiring/bi-amping, and internal wiring is Cardas cable.

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Joseph Audio RM7si loudspeaker Review context (1996)

Sidebar 1: Review context (1996)

My relatively small room measures around 19' by 16.5' by 9'. Each of the loudspeakers was positioned for the best sound (with only one pair of loudspeakers in the listening room at a time), generally some 3' from the rear wall (which is faced with books and LPs) and approximately 5' from the side walls (which also have bookshelves covering some of their surfaces). The speakers sat on 24" Celestion Si stands, these filled with lead shot and spiked to the concrete floor beneath the rug/pad.

Amplifiers used were a Mark Levinson No.333 dual-mono (…

Joseph Audio RM7si loudspeaker Big Science

Sidebar 2: Big Science

Other than impedance, all acoustic measurements were made with the DRA Labs MLSSA system and a calibrated B&K 4006 microphone. To minimize reflections from the test setup, the measuring microphone is flush-mounted inside the end of a long tube. Reflections of the speaker's sound from the mike stand and its hardware will be sufficiently delayed not to affect the measurement.

Because the altitude at Santa Fe reduces the sensitivity of all loudspeakers, I calculate sensitivity by comparing the measured, B-weighted level at 50" for a given voltage input,…

Joseph Audio RM7si loudspeaker Big Science part 2

In the vertical plane (fig.6), the RM7si is relatively tolerant of listening axis, due to the lack of frequency overlap between the drive-units. As long as the listener sits within a wide ±15 degrees angle of the tweeter axis, he or she will hear a basically flat response. Beyond those limits, a deep suckout develops in the crossover region—as always, don't listen to these speakers while standing.

Fig.6 Joseph RM7si, vertical response family at 50", normalized to response on tweeter axis, from back to front: differences in response 45 degrees-5 degrees above axis, reference…

Joseph Audio RM7si loudspeaker John Atkinson in August 2000

John Atkinson wrote about the RM7si Signature in August 2000 (Vol.23 No.8):

The $1699/pair Joseph Audio RM7si Signature is a special edition of the RM7si, which I auditioned in February 1996 (Vol.19 No.2). Because full descriptions of the speaker was included in the original review, I will only touch briefly on the differences between the original version and the sample reviewed this month.

Whereas the standard RM7si's woofer uses a bright yellow fiber-glass cone, the Signature's woofer has a much more discreet aluminum cone. But as with the '7si, a stationary phase plug is used…