Vol. 25 Issue 2 Reviews
Surrounded by Sound: The 109th Convention of the Audio Engineering Society
Los Angeles, California, USA, 22-25 September 2000

Reviewed by James Harley
Moorhead, Minnesota, USA

The twice-yearly Conventions of the Audio Engineering Society (AES) are massive events. The autumn gatherings alternate between Los Angeles and New York, with spring-times in Paris, Amsterdam, or Munich. Audio engineers of all manner of specialization from all over the world flock to these affairs, and the Fall 2000 event, held at the Los Angeles Convention Center, was no exception. Perhaps it was the Wild West Party at the Gene Autry Museum of Western Heritage that drew the crowds. Perhaps it was the huge collection of exhibitors displaying their latest and greatest wares. Whatever the reasons, the AES Convention is always worthy of attention.

For this event, there were 16 paper sessions, 14 workshops, 13 Technical Committee meetings, 12 educational events, and a whole host of Special Events. In addition, the Exhibitors Hall was packed full of new and updated products from practically any manufacturer you can think of. Given the theme of the convention, “Surrounded by Sound,” I will focus on the products and research that are relevant to multichannel audio.

Surround-sound is by no means a done deal, to judge from the research being presented at the AES. There were two paper sessions on Perception and Psychoacoustics, with reports on research relating to issues of Head-Related Transfer Functions (HRTF), among other topics. This research included “Perceptual Soundfield Reconstruction” by James D. Johnston (AT&T Research Labs, USA) and Yin Hay Lam (University of Strathclyde, UK), “Spatial Acoustic Mode Shapes of the Human Pinna” by Yuvi Kahana and Philip A. Nelson (University of Southampton, UK), “Robustness of Acoustic Crosstalk Cancellation as a Function of Frequency and Loudspeaker Separation” by Felipe Orduña (Universidad Nacional Autónoma de Mexico, Mexico), Jóse Javier López and Alberto González (Universidad Politécnica de Valencia, Spain), and “Immersive Sound Rendering Using Laser-Based Tracking” by Panayiotis G. Georgiou, Athanasios Mouchtaris, Stergio I. Roumeliotis, and Chris Kyriakakis (University of Southern California, USA). Other interesting perceptual topics included “Magnitude Estimation of Sound Source Speed” by Mark A. Ericson (Air Force Research Laboratory, USA), “Correlation between Emotive, Descriptive and Naturalness Attributes in Subjective Data Relating to Spatial Sound Reproduction” by Jan Berg (Lulea University of Technology, Sweden) and Francis Rumsey (University of Surrey, UK), and “Psychoacoustic Models and Non-Linear Human Hearing” by David J. M. Robinson and Malcolm O. J. Hawksford (University of Essex, UK).

Some of the other research relating to multichannel audio included “On-the-Fly Multitrack Mixing” by François Pachet and Oliver Delarue (Sony Computer Science Laboratory, France), and “Interactive Multichannel Sound Reproduction Linked with VRML Graphics” by Setsu Komiyama, Hiroyuki Okubo, Kazuho Ono, and Koichiro Hiyama (NHK Science and Technical Research Laboratories, Japan) and Hiroshi Asayama (Timeware Corporation, Japan).

A couple of the workshops also took on aspects of multichannel audio. Tomlinson Holman, of THX fame, led an animated discussion on “How Many Loudspeaker Channels Are Enough?” Electroacoustic composers working in “acousmatic” environments may have had some pertinent comments to add, though unfortunately none had been invited to participate. For example, sitting in on two of the multichannel presentations at the convention, held in rather large halls, it was clear to my ears, sitting toward the perimeter of the sound-fields, that five or six loudspeaker sets are not enough to fill in echoes of transient sounds present in more than one channel of the mix. One of the Special Events was a workshop on “Mixing 5.1 Surround Live,” led by Ron Streicher of Pacific Audio-Visual Enterprises. The issues focused on basic principles for mixing the audio “on the fly,” when there are no opportunities for re-takes. There was also a workshop on “Multichannel Audio Production for DTV [Digital Television],” a field that is beginning to see increased activity in some of the network studios.

An impressive demonstration of live streaming of high-resolution, multichannel audio over the Internet was given by Wieslaw Woszczyk and Jeremy Cooperstock of the McGill University research team in cooperation with Chris Cain of the University of Southern California (USC). A jazz ensemble performing in Montreal was captured using 12 channels, which were sampled by two Mytek 8X96 digital-to-analog converters (at a rate of 24-bit/96 kHz). The data packets were sent to Los Angeles over Internet2 (the necessary bandwidth and negotiations through various bottlenecks had been arranged in advance) where they were re-converted, monitored, then mixed for multichannel presentation in an auditorium at USC. A video feed was also sent along (separately), so that the audience could watch the musicians in Montreal. There was a latency-matching issue between the audio and the video, but the sound came in beautifully. It is not yet possible to assume that such bandwidth will be automatically available over the Internet, but no doubt the day is coming.

The Keynote Speech of the AES 109th Convention was given by well-known jazz musician, Herbie Hancock. Plagued by an untimely case of laryngitis, Mr. Hancock enlisted the aid of a couple of colleagues to present the history of his own involvement in digital audio and surround-sound production. In the late 1970s, he began building a digital studio, where all of his keyboard gear and other equipment would be fully controllable and able to be synchronized and patched through a matrix as necessary. This was in the very early days of personal computers and prior to the onset of MIDI. Mr. Hancock presented a few of his multichannel productions, including a brand-new 5.1 mix of a live concert in London he had just performed in the previous week.

For someone more used to the International Computer Music Conference (ICMC), it was interesting to witness the mix on the various panels and presentations of engineers, producers, and commercial musicians. While there may have been few pop stars at the paper sessions, the main draw for everyone was the Exhibition Hall, filled with all manner of new audio gear.

One of the exhibits to attract a great deal of attention was the launch of Digidesign’s new 5.1 ProTools software. This package features numerous improvements and enhancements to the earlier versions of this industry-standard audio editing software, but one of its most notable new features is the ability to create surround-sound (or any multichannel) mixes directly, and even to create more than one mix at a time (assuming one has the hardware to support these options). The graphic matrix for multichannel mixing that is included in the software can be expanded with various plug-ins, including Dolby Surround Tools, Kind of Loud Technology’s RealVerb 5.1 and SmartPan Pro, among others. In fact, the Digidesign display area featured a whole host of partners demonstrating their plug-ins, and one of the more impressive was the set of dynamic processors developed at the Groupe de Recherches Musicales called GRM Tools. Digidesign’s biggest rival at the show was probably Steinberg with its launch of the Nuendo Studio System, a hardware/software package that comes with eight channels of input/output and includes Surround Edition software, enabling real-time processing and mixing of surround-sound audio.

In the domain of loudspeakers, there were various companies exhibiting new or re-tooled products designed for optimal performance in a multichannel setting. These included Westlake Audio with its Lc3w12 monitors, and the Lc265.1 center channel loudspeaker. Tannoy presented its Universal SuperTweeter, arguing for decreased phase errors and increased transient performance, particularly for use with Super Audio CD format. Subwoofers were also displayed in abundance, including Genelec’s 1093A Active Subwoofer. Perhaps most intriguing was JBL’s EVO Intelligent Sound Reinforcement System. It is reported to enable digital control over room equalization, feedback suppression, delay settings, and amplifier dynamics. The system comes with EVOi.324 loudspeakers (each containing two drivers for low and mid ranges and a horn for high frequencies. The loudspeakers are monitored by the EVOi.net Controller.

Other interesting exhibitors included the Symbolic Sound team of Carla Scaletti and Kurt Hebel who were demonstrating the new 5.0 version of Kyma (bundled with the Capybara 320 hardware), which adds multichannel spatialization and panning features, among other things. The Cycling ’74 folks were also present, stirring up attention for the upgrades to both Max (4.0), MSP (2.0), and Pluggo (2.1). They also had some interesting interfaces on hand, including the CM Automation Motor Mix controller, and the MTC Express Multi-Touch Controller. A creative extension of MIDI and audio into the visual realm the Cycling ’74 team were working with was Videodelic, developed by Eric Wenger (of MetaSynth fame). On the nitty-gritty side, Analog Devices was promoting its Melody single-chip decoder, that works with THX Surround EX, DTS Extended Surround, and Dolby Digital. This should mean that consumers will be able to run these different encoding schemes through one processor.

There was, of course, much, much more to see at the AES Exhibition Hall—new microphones, preamplifiers, processors, consoles, amplifiers, recorders, network products, computer hardware/software, and so on. Unlike the ICMC, many people attend for a day just to browse the aisles and see what’s new. For the engineers and researchers, the glitz and hawking of the displays provided a break from the paper sessions and other presentations. The AES Convention is definitely worth attending. There is important work being done through the various Technical Committees of the AES, and it behooves all of us to keep up with the new developments (for further information, consult http://www.aes.org).