Audacious Audio

Bang & Olufsen's BeoLab 90 is not a loudspeaker to take on lightly. Though its size—49.33" high by 28.9" wide by 29.4" deep—and weight (302 lbs each) meant a major disruption of my listening room, which is also our living room, my wife assented. Its price of $84,990/pair puts it far beyond anything I might consider buying—and the complexity of the BeoLab 90, which has its own dedicated amplifiers and DACs, makes it impossible for a reviewer—or consumer—to directly compare it with any other loudspeaker. So be it.

It has been 20 years since I first became aware of the British company Data Conversion Systems, which manufactures audio products under the dCS brand. Rather than use off-the-shelf conversion chips, the groundbreaking dCS Elgar D/A converter, which I reviewed in our July 1997 issue, featured a then-unique D/A design that they called a Ring DAC. This featured a five-bit, unitary-weighted, discrete DAC running at 64 times the incoming data's sample rate—2.822MHz for 44.1kHz-based data, 3.07MHz for 48kHz-sampled data and its multiples—with upsampling and digital filtering and processing implemented in Field Programmable Gate Arrays (FPGAs). Oversampling to a very high sample rate allows the word length to be reduced without losing resolution, and use of a low-bit multi-bit DAC makes for very high accuracy in the analog voltage levels that describe the signal. (If this seems like voodoo, for a given signal bandwidth, bit depth and sample rate are related. To oversimplify, double the rate, and you can reduce the bit depth by one bit while preserving the overall resolution.)

I wrote several issues back that my first high-end headphones were Koss Pro4AAs, which I bought in 1972 following a positive review in the British magazine Hi-Fi News. Although that review didn't mention that the Pro4AAs were relatively fragile (footnote 1), I nonetheless loved their sound. They were the best headphones I'd heard—until, a couple years later, I was playing bass on some sessions for record producer Tony Cox. Tony had a pair of signal-energized electrostatic headphones, Koss ESP-6es, which were heavy and clunky—but they opened my ears to the sound quality that could be obtained from "cans." I didn't hear better until after I'd moved to Santa Fe, in 1986, and J. Gordon Holt loaned me his review samples of the Stax SR-Lambda Pros.

The top-of-the-line model from America's leading headphone manufacturer, these are bulky, heavy, very business-like in appearance, and very, very good.

The ESP-9 is dual-powered: from the AC line, or from the input signal itself, The power supply is rather large and heavy, and appropriate in appearance to the phones. Amplifier connections are via wires with spade lugs attached, and speaker connections are made to the rear of the power supply. A front-panel switch selects speaker or headphone operation, and terminates the amplifier outputs with 10 ohms in the Phones position.

Construction is typically top-of-the-line Koss: Rugged, nicely finished, and apparently very durable, and the phones are easy to handle. (Many headphones are so loosely pivoted on their headbands that they swing into impossible positions whenever you pick them up.)

Simaudio saw disc-based digital audio in its rear-view mirror at least as far back as 2011, when it introduced the Moon Evolution 650D and 750D—two iterations of what it called a "digital-to-analog converter CD transport." These were actually multiple-input CD players, but Simaudio was evidently so eager to distance itself from the spinning disc that it went with a product category that, in spite of its cumbersome, run-on name, drew a clean line between the disc-reading and signal-processing functions—while bestowing upon the former second-class citizenship.

Life is too short to put up with poor-sounding headphones, I mused the other morning, during my 60-minute commute on the NYC subway. All around me, straphangers gripped smartphones and listened to multicolored Beats, noise-canceling Boses, white Apple earbuds, and, only rarely, Sennheisers and Grados.

"This is getting to be a habit."

That's how I ended the first paragraph of my review of Bowers & Wilkins' 800 Diamond speaker, in the May 2011 issue; apparently, Stereophile's habit of reviewing models from B&W's 800 series remains unbroken.

Later in that review, I said that "The 800 Diamond doesn't look radically different from its predecessors." That doesn't apply to the 802 D3 Diamond ($22,000/pair). It's still a three-way system with tapered-tube high-frequency and midrange enclosures, stacked and nestled into a generous bass enclosure that's vented on the bottom into the space between it and its plinth.