Editor's Introduction: In 2013, lossy compression is everywherewithout lossy codecs like MP3, Dolby Digital, DTS, A2DP, AAC, apt-X, and Ogg Vorbis, there would be no Web audio services like Spotify or Pandora, no multichannel soundtracks on DVD, no Bluetooth audio, no DAB and HDradio, no Sirius/XM, and no iTunes, to quote the commercial successes and no Napster, MiniDisc, or DCC, to quote the failures. Despite their potential for damage to the music, the convenience and sometimes drastic reduction in audio file size have made lossy codecs ubiquitous in the 21st century. Stereophile covered the development of lossy compression; following is an article from more than two decades ago warning of the sonic dangers.Editor
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.
As Chester Rice, co-inventor of the moving-coil loudspeaker, once ruefully observed: "The ancients have stolen our inventions." So often, what is painted as new and innovative turns out to be something someone thought of long before. We have a habit of forgetting, and that applies not only to inventions, but to knowledge of other kinds as well.
It's a Vinyl World, After All: Michael Fremer's Guide to Record Cleaning, Storage, Handling, Collecting, & Manufacturing in the 21st Century
MF Productions mxangle3 (DVD). 2008. Michael Fremer, prod.; Joe Shelesky, Andre Kruger, Jeff Wilerth, dirs.; Joe Shelesky, editor. $30; available from Stereophile's secure e-commerce page.
Until the Recording Industry Association of America hit the headlines in recent years with its antipiracy campaign, the initials RIAA meant one thing to seasoned audiophiles: the vinyl-disc equalization characteristic introduced in the 1950s to standardize what had previously been an anarchy of different EQs. Three decades later, as CD gained ascendance, a large proportion of audiophiles still knew what RIAA equalization was, and a good number of them had some idea or better of what the RIAA EQ curve looked like, and why it was applied.
There was a time, as recently as 40 years ago, when frequencies below 100Hz were considered extreme lows, and reproduction below 50Hz was about as common as the unicorn. From our present technological perch, it's too easy to smirk condescendingly at such primitive conditions. But just so you're able to sympathize with the plight of these disadvantaged audiophiles, I should tell you that there were two perfectly good reasons for this parlous state of affairs. First of all, program material at that time was devoid of deep bass; not because it was removed during disc mastering but simply because there wasn't any to begin with. The professional tape recorders of the day featured a frequency response of 5015kHz, ±2dBjust about on a par with the frequency performance capability of a cheap 1988 cassette tape deck.
Because loudspeakers interact with the acoustics of the room in which they are used, optimizing their positions within that room pays major dividends. Inexpensive speakers, optimally set up, may well outperform more expensive models just plonked down willy-nilly.
Headphones get pretty short shrift in much of the hi-fi press, which is puzzlingthe headphone market is burgeoning. I don't know what the equivalent US figures are, but in recent years the UK headphone market has increased by an annual 1520% in both units sold and overall revenue. It's easy to dismiss this as a natural byproduct of the Apple iPod phenomenon, but 20% of the market value is now accounted for by headphones costing over $120; a significant subset of consumers would seem to be looking for quality. When you also consider that many people's first exposure to higher-quality audio comes via headphones, there is ample reason for treating them more seriously.
Swiss Precision: The Story of the Thorens TD 124 and Other Classic Turntables Swiss Precision: The Story of the Thorens TD 124 and Other Classic Turntables
by Joachim Bung. Published by Joachim and Angelika Bung, Schmitten, Germany (firstname.lastname@example.org), 2008. Hardcover, 288 pages, four-color, ISBN 978-3-00-021162-1. Price: €59 plus overseas mailing.
Surround Sound: Up and Running (Second Edition)
by Tomlinson Holman. Published by Focal Press, an imprint of Elsevier (footnote 1) (Oxford, England, UK; www.elsevier.com). 2008. Paperback, 248 pages, ISBN 978-0240808291. $44.95.
Recently, I assessed four disparate room-correction systems based on digital signal processing (DSP): Copland DRC205, Lyngdorf Audio RoomPerfect, Velodyne SMS-1, and Meridian DRC. I concluded that Meridian's approach—which applies IIR (Infinite Impulse Response) "anti-resonance" filters to suppress room resonant modes, if only partially—was, in many respects, the best. What I particularly like about Meridian DRC is that, unlike the Copland and Lyngdorf processors, its approach to system tonal balance is largely hands-off. Yes, it lightens up the extreme bass a little, as you'd expect, but it doesn't recast the system balance in any way that might prove undesirable. If you like your system's tonal character as it is, Meridian DRC behaves just as you'd want a room-correction system to behave: it quells room resonance effects while leaving the system's essential sound well alone.
Why, in loudspeaker reviews, is impedance measured (assuming that the magazine in question bothers to measure anything)? Generally, for one principal reason only: to establish whether the speaker presents an "easy" or a "difficult" load to its partnering amplifier. In the design context, much more information can be extracted from a graph of speaker impedance vs frequency—such as details of the bass alignment, and indications of internal or structural resonances that can be difficult to identify by acoustical measurements. But for a magazine audience, the principal interest in a loudspeaker's load impedance lies in gaining some indication of its compatibility with a given amplifier.
When the brief flowering of quadraphonics began in the early 1970s, I was still at school. As a nascent but impecunious audiophile, I therefore had a ringside seat at the audio industry's first attempt to go multichannel—and, even for the disinterested onlooker, it wasn't a pretty spectacle.