Features

Sort By:  Post Date TitlePublish Date
Art Dudley  |  Nov 21, 2018  |  47 comments
Since fake news is on everyone's minds these days—I would say it's been in the news a lot, but that kind of reasoning is too circular even for me—it's worth keeping in mind that there's also such a thing as fake praise. You see it every day, whether it's a fake Google review—an alarming number of businesses seem unaware that real people don't actually say things like "the team at New Hartford Chevrolet really listened to all of my needs"—or fake trophies handed out to all 20 co-captains of your child's soccer team.

Then there are fake awards.

Jim Austin  |  Oct 02, 2018  |  44 comments
The most notable aspect of Benchmark Media Systems' DAC3 HGC ($2195), which I favorably reviewed in the November 2017 Stereophile (footnote 1), is its low noise floor. John Atkinson's measurements corroborated Benchmark's claim that the DAC3 is capable of "at least" 21-bit performance. While significantly less than the theoretical potential of a 24-bit data format, 21 bits is still the state of the art, and corresponds to a dynamic range—the ratio of the highest achievable digital-domain volume to the DAC's internal noise—of 128dB. That's well above the dynamic range that most power amplifiers can achieve. A good-measuring high-end solid-state amplifier is likely to have a dynamic range—the highest attainable ratio of signal to noise—of about 100dB ref. its maximum power.
John Atkinson  |  Aug 14, 2018  |  47 comments
In a series of recent feature articles for Stereophile, Jim Austin has examined how the controversial MQA codec works: "MQA Tested, Part 1," "MQA Tested Part 2: Into the Fold," "MQA Contextualized," "MQA, DRM, and Other Four-Letter Words," and, most recently, "MQA: Aliasing, B-Splines, Centers of Gravity." I doubt there is a Stereophile reader who is unaware of the fracas associated with MQA, and I have been repeatedly criticized on web forums for describing its underlying concept as "elegant."

But elegant it is, I feel.

Robert Harley  |  Jul 10, 2018  |  First Published: May 01, 1995  |  11 comments
The men behind HDCD (L–R: Pflash Pflaumer, Michael Ritter, Keith Johnson

High Definition Compatible Digital® (HDCD®), the proprietary process for improving the sound of 16-bit digital audio, has finally arrived. More than a dozen digital processors using the technology are on the market, and the professional encoder used to master HDCD discs is following closely behind.

John Atkinson  |  Jul 03, 2018  |  First Published: May 01, 1981  |  40 comments
The author demonstrating stereo microphone techniques at an English audio show in 1981.

For most people the terms hi-fi and stereo are synonymous, and yet it is clear that there is still a great deal of confusion over what the word "stereo" actually means. There isn't even a consensus of opinion amongst producers of records, designers of hi-fi equipment, audio critics and music lovers as to the purpose of stereo, and considering that the arguments show no sign of diminishing in intensity, it is instructive to realise that 1981 sees both the 100th anniversary of Clement Ader's first stereo experiments and the 50th anniversary of Alan Blumlein's classic patent on stereo.

Dick Olsher, J. Gordon Holt, Martin Colloms  |  Jun 07, 2018  |  First Published: Feb 01, 1986  |  0 comments
Do-It-Yourself (DIY) loudspeaker projects are quite common in the UK, where details about several excellent designs, including a recent one by Martin Colloms, have been published for public domain consumption. Stateside, the situation is rather grim, where only an occasional subwoofer project (always popular) makes it into the commercial magazines.
Jim Austin  |  May 17, 2018  |  160 comments
The right thing at the wrong time is the wrong thing.—Joshua Harris

The sampling theory formulated by Claude Shannon in the late 1940s had a key requirement: The signal to be sampled must be band-limited—that is, it must have an absolute upper-frequency limit. With that single constraint, Shannon's work yields a remarkable result: If you sample at twice that rate—two samples per period for the highest frequency the signal contains—you can reproduce that signal perfectly. Perfectly. That result set the foundation for digital audio, right up to the present. Cue the music.

Jim Austin  |  Apr 19, 2018  |  47 comments
In an article published in the March 2018 Stereophile, I wrote that critics have been attacking MQA, the audio codec developed by J. Robert Stuart and Peter Craven, by accusing it of being lossy. The critics are right: MQA is, in fact, a lossy codec—that is, not all of the data in the original recording are recovered when played back via MQA—though in a clever and innocuous way. For MQA's critics, though, that's not the point: They use lossy mainly for its negative emotional associations: When audiophiles hear lossy, they think MP3.
Jim Austin  |  Feb 13, 2018  |  177 comments
When you come to a fork in the road, take it.—Yogi Berra

Over one busy week in 1986, Karlheinz Brandenburg laid the foundation of a technology that a few years later would upend the record business. Brandenburg, a PhD student in electrical engineering at the Friedrich-Alexander University Erlangen-Nuremberg, was figuring out how to code digital music efficiently enough that it could be delivered over digital telephone lines. A patent examiner had concluded that what the application proposed was impossible, so over a week of late nights, Brandenburg produced the proof of concept and more. It was another decade before the technology—MPEG-2 level III, more commonly known as MP3—would find its true home, the Internet.

Jim Austin  |  Jan 06, 2018  |  28 comments
Loss is nothing else but change, and change is Nature's delight.—Marcus Aurelius

Master Quality Authenticated (MQA), the audio codec from industry veterans Bob Stuart and Peter Craven, rests on two pillars: improved time-domain behavior, which is said to improve sound quality and what MQA Ltd. calls "audio origami," which yields reduced file size (for downloads) and data rate (for streaming). Last month I took a first peek at those time-domain issues, examining the impulse response of MQA's "upsampling renderer," the output side of this analog-to-analog system (footnote 1). This month I take a first look at the second pillar: MQA's approach to data-rate reduction. In particular, I'll consider critics' claims that MQA is a "lossy" codec.

Jim Austin  |  Dec 12, 2017  |  213 comments
I don't think I've ever seen an audio debate as nasty as the one over Master Quality Authenticated (MQA), the audio-encoding/decoding technology from industry veterans Bob Stuart, formerly of Meridian and now CEO of MQA Ltd., and Peter Craven. Stuart is the company's public face, and that face has been the target of many a mud pie thrown since the technology went public two years ago. Some of MQA's critics are courteous—a few are even well-informed—but the nastiness on-line is unprecedented, in my experience.
John Atkinson  |  Dec 05, 2017  |  First Published: Nov 01, 1980  |  22 comments
The problem confronting the magazine reviewer when organising the necessary listening tests to accompany/reinforce the measured behavior of a device under test is complex. There has never been a problem with the measurement aspect; as long as someone has access to the same test gear—and full knowledge of the test conditions—then he should be able to replicate the critic's findings exactly (assuming an infinitely narrow spread of behaviour from sample to sample—a rasher assumption with some manufacturers' equipment than of others). However, when it comes to determining reliably the audible (or inaudible?) effects on music program by an amplifier/cartridge/loudspeaker etc. then the going gets tough.
Art Dudley  |  Nov 16, 2017  |  9 comments
The mice in the walls call summer to close while nets come down and leaves turn dead red, but by the time you see this there'll be holiday music in the air . . . and some generous soul might, just might, sneak a few looks through this issue of Stereophile to see what gifts to buy before the tree goes up and presents are opened—and all will be nice!

And what better way to serve those possible givers of audio gifts—and, at the same time, honor our hobby's most deserving designers and manufacturers—than with our annual Product of the Year awards?

Jim Austin  |  Oct 19, 2017  |  12 comments
It's day five of our planned month-long stay à Paris, late April through most of May. My wife is here for work—for me, it's strictly for pleasure—and we're enjoying Paris's rich, sensual goodness: food, museums, architecture, coffee, people, food. And yet, earlier today, when we were out for a walk—we've been walking close to 10 miles each day, exploring the city—I realized that my life here has been missing something important.
Bill Sommerwerck, Others  |  Aug 08, 2017  |  First Published: Sep 01, 1985  |  17 comments
The issue is this business of "single-speaker" listening and demonstration, which has become fashionable in the UK.

The premise: bringing a second pair of loudspeakers into your auditioning room upsets the sound of the pair you're listening so badly that the first speaker's ability to correctly reproduce the timbre of musical instruments is destroyed. This observation is almost surely correct.

Pages

X