Reference

Room acoustics, and their importance, may not be subjects which we ponder daily here at Stereophile, but they are never far from our consciousness. Two recent events served to spotlight them yet again: the setting-up of our first-ever panel listening test of moderately priced loudspeakers (Vol.14 No.7), and a letter from a reader requesting advice on room problems. Both reminded us---if a reminder was needed---that although the perfect room does not exist, there are things that can be done to make the most of even an admittedly difficult situation. That reader's letter, in particular, brought home the fact that we cannot really discuss this subject too often. It's easy to forget that comments made here months (or years) ago are beyond the experience of newer readers. A new audiophile's most frequent mistake is to overlook the significance of his or her listening room, while the experienced listener will too often take the room for granted.

Because I'm suspicious of just twiddling knobs to make the sound "nice," I didn't rely solely on my ears when I used the Z-Systems rdp-1 that I review elsewhere in this issue for speaker and room contouring. Instead, I used the ETF speaker/room-analysis software from Acoustisofthttp://www.acoustisoft.com">Acoustisoft; to help me manipulate the equalizer properly. This program can measure the first-arrival, on-axis speaker response, as well as the room response with its early and late reflections and its resonances.

In 1977, just as I was about to take my first faltering steps in hi-fi journalism, the UK's Hi-Fi News ran two articles, translated from French originals by Jean Hiraga, that seemed to me and many others to turn the audio world we knew upside down. The second of them, "Can We Hear Connecting Wires?" was published in the August issue and is the better remembered because it introduced many English-speaking audiophiles to the contention that cables can sound different. The earlier article, published in the March issue, was less earthshaking but still an eyebrow-raiser of considerable force. Simply titled "Amplifier Musicality," it was a response to the word musicality being increasingly used in subjectivist circles to describe the perceived performance of amplifiers and other audio components. It was implicit that musicality was a quality not captured by conventional measurement procedures—a lack of correlation that Hiraga's article sought to address.

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.

In his review of the three-way, active Dutch & Dutch 8c loudspeaker in the August 2019 issue of Stereophile, Kalman Rubinson concluded that "The D&D 8c demonstrates that active, DSP-empowered speakers are the future." I was equally impressed by the 8c's measured performance—a superbly flat on-axis response and an unmatched control of dispersion over the entire audioband—and asked to borrow a pair so I could experience the speakers in my own listening room.

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.

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.