U-Turn Audio is funding their project through Kickstarter and hopes to raise $60,000 by Monday, January 21, 2013. As I write, 90 backers have pledged $15,666. (Is that a multiple of 33.3?)
Visit U-Turn Audio's Kickstarter page for more info…
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Back in August, we told you about the proposed $150 Orbit turntable from upstart U-Turn Audio. The company is now moving closer to making their dream a reality. And, if they can keep their promise of high-performance sound and construction, that reality will likely be a dream-come-true for many young and budget-minded music lovers.
In the summer of 2011, Stereophile's long-time editor in chief, John Atkinson, was invited by the Technical Council of the Audio Engineering Society to give the Richard C. Heyser Memorial Lecture at the 131st Audio Engineering Society Convention in New York, October 21, 2011.
The AES website notes that the Richard C. Heyser Memorial Lecture series was established in May 1999 by the AES Technical Council, the Board of Governors, and the Richard Heyser Scholarship Fund to honor the extensive contribution to the Society by this outstanding man, widely known for his ability to communicate new…
"What Happened to the Negative Frequencies?"
Nothing happened to them, of course, as I will show, but you mustn't forget that they are always there.
Nothing happened to them, of course, as I will show, but you mustn't forget that they are always there.
Everyone in this room will be familiar with the acronym "FFT." The Fast Fourier Transform is both elegant and ubiquitous. It allows us to move with ease between time-based and frequency-based views of audio events. You will all be familiar with the following example. Here is the waveform of a short section of a piece of music:
And here is the spectrum of that music:
This usefulness of the FFT algorithm—…
Is There Something There?
Over the almost 35 years during which I have taken part in or organized listening tests, I have become convinced that what is fundamentally important is to respect the listeners—to listen to what they tell me. Yes, there may be a trivial explanation for what they hear. But there may be something there. When I first heard of so-called LP "demagnetization"—where an LP sounds better after being subjected to the action of, for example, a bulk tape eraser—I was skeptical. But I didn't dismiss the reports; I just filed them away for further investigation, if and when…
Over the almost 35 years during which I have taken part in or organized listening tests, I have become convinced that what is fundamentally important is to respect the listeners—to listen to what they tell me. Yes, there may be a trivial explanation for what they hear. But there may be something there. When I first heard of so-called LP "demagnetization"—where an LP sounds better after being subjected to the action of, for example, a bulk tape eraser—I was skeptical. But I didn't dismiss the reports; I just filed them away for further investigation, if and when…
Measuring Sound Quality
Table 1: What is heard vs what is measurable
Table 1: What is heard vs what is measurable
This is a table I prepared for my 1997 AES paper on measuring loudspeakers. On the right are the typical measurements I perform in my reviews; on the left are the areas of subjective judgment. It is immediately obvious that there is no direct mapping between any specific measurement and what we perceive. Not one of the parameters in the second column appears to bear any direct correlation with one of the subjective attributes in the first column. If, for example, an engineer needs to measure a loudspeaker's…
Case Study 2: Loudspeakers
During a visit to Canada's National Research Council many years ago, I noticed, stuck to the wall of the prototype IEC listening room, a page of results from one of Floyd Toole's seminal papers on the blind testing of loudspeakers. The scoring system was the one that Floyd developed and that I subsequently used for blind tests at Stereophile: "0" represents the worst sound that could possibly exist, "10" the perfection of live sound. On this scale, a telephone, for example, rates a "2." The speakers in Floyd's test pretty much covered the range of possible…
During a visit to Canada's National Research Council many years ago, I noticed, stuck to the wall of the prototype IEC listening room, a page of results from one of Floyd Toole's seminal papers on the blind testing of loudspeakers. The scoring system was the one that Floyd developed and that I subsequently used for blind tests at Stereophile: "0" represents the worst sound that could possibly exist, "10" the perfection of live sound. On this scale, a telephone, for example, rates a "2." The speakers in Floyd's test pretty much covered the range of possible…
Case Study 3: Digital Recording & Playback
The title of this lecture asks "Where did the negative frequencies go?" Once we enter the world of digital audio, they are very much present. Here is the spectrum of the music waveform I showed earlier:
The title of this lecture asks "Where did the negative frequencies go?" Once we enter the world of digital audio, they are very much present. Here is the spectrum of the music waveform I showed earlier:
And this is the spectrum of the same signal after it has been sampled in the time domain:
The positive (red) and negative (blue) spectra are mirrored around the sampling frequency and all of its harmonics, the latter extending to, if not infinity, then to something practically close to it. If you wish to play back…
Case Study 4: Amplifiers
To many audio engineers, the amplifier is a solved problem. Static distortion and noise levels can be restricted to well below the threshold of human hearing at all audible frequencies and at all power levels short of clipping. Yet the darned things continue to surprise by sounding different—perhaps only slightly different, and sometimes for trivial reasons, such as too high an output impedance. But over the years I have been measuring amplifiers, some things have fallen out of the cloud of measured data: factors that are shared by amplifiers that sell well to…
To many audio engineers, the amplifier is a solved problem. Static distortion and noise levels can be restricted to well below the threshold of human hearing at all audible frequencies and at all power levels short of clipping. Yet the darned things continue to surprise by sounding different—perhaps only slightly different, and sometimes for trivial reasons, such as too high an output impedance. But over the years I have been measuring amplifiers, some things have fallen out of the cloud of measured data: factors that are shared by amplifiers that sell well to…
John Atkinson reviewed the Musical Fidelity M1DAC in January 2013 (Vol.36 No.1):
Sam Tellig enthusiastically reviewed this inexpensive solid-state D/A processor in March 2011. "What I mainly heard from the M1DAC was nothing: an absence of artifacts, if you want to get fancy," he wrote. "There was no fudging of detail, no smearing of transients. Purity of tone was exceptional."
Some months after that review was published, the M1DAC was updated. Whereas the original version's USB input was limited to 48kHz sample rates and below and 16-bit data, the new version uses the popular…
Here in the age when rock stars like Jagger and Richards are not only still breathing, but are now turning 70—“I’d rather be dead than sing “Satisfaction” when I’m 45,” Mick once said with a straight face—seeing older bands reunite and “play” can be very disappointing. There are some, who shall remain nameless, that I have sworn off of completely. The past can never really be recaptured. And no one escapes the ravages of time. Neither they nor you are as young as you once were.
Before I sat down to write about the new Led Zep concert film, Celebration Day, I watched the old Led Zep…