Reference

Author's Note: We are grateful to Stereophile for the opportunity to address some frequently repeated technical questions appearing in comments to articles. Recently this has included misunderstandings about noise calculation, dynamic range, resolution, definition, music spectra, channel capacity, lossless processing and temporal aspects of digital channels.

To simplify this document we have grouped the topics and set them as questions and answers either as response, tutorial or axiom. Some months ago we published a comprehensive Q&A for an online forum and to avoid repetition we occasionally refer to topics already discussed there (see [37] in the "References" sidebar).—J. Robert Stuart

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.

Get Better Sound


By Jim Smith. Quarter Note Press (Cumming, GA), 2008. Paperback, 293 pages. ISBN 978-0-9820807-0-2. $44.50.
Web: www.getbettersound.comhttp://www.getbettersound.com">www.getbettersound.com;.

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">http://ssl.blueearth.net/primedia/home.php">secure e-commerce page.

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.

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 (info@td-124.de), 2008. Hardcover, 288 pages, four-color, ISBN 978-3-00-021162-1. Price: €59 plus overseas mailing.

Recently, I assessed four disparate room-correction systems based on digital signal processing (DSP): Copland DRC205, Lyngdorf Audio RoomPerfect, Velodyne">http://www.stereophile.com/musicintheround/1105mitr">Velodyne SMS-1, and Meridian">http://www.stereophile.com/musicintheround/706mitr">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.