Reference

When I decided to write a piece on the subject of concert-hall acoustics, I realized that almost all discussion concerning this topic is based on the viewpoint of the listener in the audience. While this is important (since the primary purpose of any hall is to bring audience and performance together), the criteria that musicians employ in concert-hall evaluation address sonic parameters that are probably not obvious to the casual listener, and may often be at odds with conclusions reached from the other side of the footlights. Some readers might feel that any discussion of concert halls has no place in a publication such as Stereophile; they may have a point, especially if their sole aim through audio is to produce sonic spectacle, rather than to recreate an artistic event. I believe, however, that there are some readers who would like to gain some insights into the specific problems and acoustical considerations presented to performing musicians, and possibly come away with some fresh ideas to incorporate in their listening criteria.

The introduction in 1982 of the compact disc ushered in the age of digital audio. Audiophiles now have lots of new digital toys and technologies at their disposal, including SACD, DVD-Audio, MP3 players, hard-drive–based CD players, and digital equalization and room correction, to name a few. Videophiles have similarly benefited from digital technology, with an armamentarium that includes high-definition television, DVD-Video, Blu-ray, HD DVD (the latter two still on the horizon), DLP, LCoS, and D-ILA, among others. Action-based films have also benefited from breathtaking, digitally enhanced special effects. Even those of us who still prefer LPs must acknowledge—reluctantly, perhaps—the incredible impact that digital has had on our hobby (footnote 1).

If anyone ever thinks to compile a list of the 100 seminal audio papers that should be found in every tech-aware audiophile's filing cabinet, Harry Olson's "Direct Radiator Loudspeaker Enclosures" deserves to feature in it. Originally presented at the second Audio Engineering Society Convention, in October 1950, it was published in Audio Engineering in 1951. In 1969—in a rare and certain acknowledgement of its classic status—the AES republished it in its Journal (footnote 1).

In the October 1994 Stereophile (Vol.17 No.10, p.39), I discussed my experiences with the DTS audio data-reduction code/decode switch box, which, briefly, is a two-channel box that makes use of the algorithm DTS has proposed for their version of discrete multichannel sound for laserdiscs.

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 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.

Ever since the first electrical loudspeaker—a glorified headphone with a horn on it—was outmoded by the balanced-armature cone speaker, paper has been the standard diaphragm material for speakers reproducing low frequencies. The Rice-Kellogg moving-coil transducer replaced the balanced-armature driving system in 1925, but the paper cone remained. And although many improvements have since been made, were no more major changes in loudspeaker design for over 30 years!