117th AES Convention

October 1, 2004

The Audio Engineering Society's pattern of alternating the fall convention between the east and west coasts has proven to be a successful formula. It returns to San Francisco this year, a city that hosts conventions well.

The theme of the convention is the Art of Audio, which stirs ideas of the creative side of originating and distributing audio. While quality audio can be defined by science, the art of dealing with audio gives it life. Radio, being an aural medium, knows this well.

The Audio Engineering Society is a strong technical organization, and because of its leading technical focus, the sessions, workshops and other convention events are packed with valuable information. Complete details on all the sessions are available from the AES website, but we have identified several events that should be of interest to radio broadcasters attending the convention. Included on page 49, is a special look at four radio-specific events that will be held during the convention.

Session Preview

Oct. 28

TUTORIAL: Subjective Microphone Comparisons
9 a.m. to 11 a.m.

Jurgen Wahl of Sennheiser/Neumann will analyze the variables that affect predicting a microphone's performance in actual applications. This will provide an understanding as to why microphones with seemingly identical technical specifications sound different, even when used under the same circumstances. The tutorial will demonstrate how to concentrate on less complex segments of performance behavior.

TECHNICAL TOUR: KQED - Public Broadcasting Radio and TV Station
9 a.m. to 1 p.m.

KQED is San Francisco's primary public broadcasting outlet. First taking to the airwaves 50 years ago and this year to broadcast educational TV, KQED television and radio have been been flagships of the national public broadcasting networks. Still leading the way, KQED-TV first began digital broadcasting in 2000. This tour will encompass the radio and television facilities.

PAPER: Lossy and Lossless Audio Coding
9 a.m. to 11:30 a.m. and 1 p.m. to 4 p.m.

This all-day session covers many aspects of audio coding in 11 presentations. Of particular interest are the papers that examine the needs of providing surround-sound encoding that ensures compatibility with stereo systems. Other papers address applications and explanations of AAC Plus and Dolby Digital Plus, evaluation and measurement of perceptual encoders, and the use of SBR with MPEG Layer II for Eureka-147.

Oct. 29

WORKSHOP: Firewire In Studios: Benefits and Challenges
11:30 a.m. to 1:30 p.m.

Richard Foss of Rhodes University, Grahamstown, South Africa moderates the panel of Jun-ichi Fujimori of Yamaha, Morten Lave of TC Applied Technologies, Bob Moses of Island Digital Media Group, Tim Thompson of Kurzweil Music Systems and Mark Olleson of Yamaha as they discuss the physical connection of devices with cable types and lengths; audio transmission with sample rates, word lengths, synchronization and jitter; device control with MIDI and other protocols; software integration of Firewire devices and software plug-in management within digital audio workstations and Mlan.

HISTORY: Classic Microphones from the Golden Age of Radio
1 p.m. to 2 p.m.

Barry Brose of Highland Laboratories will demonstrate some classic microphones. He will describe how they were built, how they look, how they were used and how they sound. The demonstration includes carbon, condenser, dynamic and velocity microphones. He will also discuss the invention of the cardioid microphone.

WORKSHOP: Mastering for Low Bit-Rate Perceptual Codecs
2 p.m. to 4 p.m.

Bob Ludwig of Gateway Mastering Studios leads panelists John Arthur of Apple Computer, Bob Katz of Digital Domain and John Loose of Dolby Laboratories as they discuss the success of MP3 and AAC audio distribution and satellite radio and what needs to be done in the mastering process to plan for these codecs. IBOC also uses a lossy codec and the concepts discussed here will also apply. Some audio examples will be provided to illustrate certain points.

TUTORIAL: Digital Plumbing for Studio, Broadcast and Live Audio
2 p.m. to 4 p.m.

Michael Poimboeuf of Digidesign will present an overview of commonly used digital audio interconnection technologies, including cabling, circuits, modulation theory and analysis techniques for performance measures. The interconnect technologies will include AES-3, S/PDIF and Ethernet. Cabling includes shielded 110Ω twisted pair, UTP and ScTP category cable (CAT-5/5e/6) and 75Ω coaxial cable. Circuits include clock/data recovery and PLLs. Analysis techniques and performance measures range from eye-diagrams, and transport jitter measurements, to bit-error rate (BER) estimation based on signal-to-noise measures such as NEXT, FEXT and alien crosstalk.

Oct. 30

WORKSHOP: Architectural Acoustics for Film and Broadcast Studios
9 a.m. to 11 a.m.

Moderator David Schwind of Charles M. Salter Associates will host panelists George Augsburger of Perception, Russ Berger of Russ Berger Design Group, Tomlinson Holman of TMH and Jan Voetmann of Delta Acoustics. They will review aspects of good architectural acoustic design practice for new facilities. Topics for discussion, in the form of project case studies, will include planning considerations and design criteria, internal and external sound isolation, the use of noise criteria (NC) and room criteria (RC), noise reduction, structure-borne noise, proper HVAC system design and room shape and its influence on acoustics.

WORKSHOP: Lossless Audio Coding: MPEG and Defacto Standards
11:30 a.m. to 1:30 p.m.

Jurgen Herre of Fraunhofer IIS and panelists Peter Craven of Algol Applications, Ralf Geiger of Fraunhofer IDMT, Tillman Liebchen of the Technical University of Berlin and Werner Oomen of Philips will detail the popularity of using lossless audio coding in the context of high-definition audio and archiving. This workshop will also provide an overview of widely used current systems for lossless audio coding and their applications. It will pay special attention to the technology developed by the ongoing MPEG work on this topic, which provides a number of novel features compared to existing systems, such as combined lossy/lossless audio coding, fine grain scalability and compression of floating point audio.

WORKSHOP: Grounding and Shielding
11:30 a.m. to 1:30 p.m.
Bill Whitlock of Jensen Transformers demystifies the black art of grounding and interfacing. His tutorial will focus on the real sources of system noise and ground loop problems that routinely overlook or ignore the basic laws of physics. Balanced and unbalanced audio, ac power distribution and safety, code compliance and common-impedance coupling will be covered. A simple troubleshooting method that uses no test equipment and can pinpoint the exact location and cause of system noise will be described.

Radio @AES

The AES Convention covers audio in all its forms. While radio is a broad distribution of audio information and entertainment, there are elements of the convention that are distant from radio's view. However, there are four events this year that target radio directly.

The coordinator of the convention broadcasting events is David Bialik, a systems engineering consultant, who has arranged broadcast-related sessions for the AES for several years.

On Oct. 28 from 1:30 to 3 p.m., the session Opportunities for the Engineer in the Digital Broadcast World will address shifting job prospects and the training necessary for a successful career in broadcasting today. The panel will include Andy Butler of PBS, Tony Masiello of XM Radio, Glynn Walden of Viacom/Infinity, David Wilson of the Consumer Electronics Association (CEA) and David Layer of the NAB and NRSC.

On Oct. 29 from 10 a.m. to 1 p.m., Bialik will moderate the 14th AES Digital Broadcast Radio Forum. On hand to discuss the ongoing evolution and the future potential of digital radio will be a panel including David Layer of the NAB and NRSC, Mike Starling of NPR, Scott Stull of Ibiquity; Tony Masiello of XM and David Wilson of the CEA.

On Saturday, Oct. 30, the session Surround Sound for Digital Radio will be held from 9 a.m. to noon. Emil Torick will be the moderator. The panelists will include Robert Orban of Orban, Rocky Graham of Dolby Labs, Frank Foti of Omnia Audio, Robert Reams of Neural Audio, Alan Kraemer of SRS Labs and Tony Masiello of XM Radio. They will discuss the introduction of surround sound to broadcasting, and its implications on the future of stereo. The panel will also explore various 5.1 systems currently in the market and their ability to interface with existing broadcast and bandwidth restraints.

There is one final event likely to appeal to anyone with an interest in radio history. On Oct. 28 from 4:30 to 5:30 p.m., Mike Adams will present an abstract called The Birth of Radio Broadcasting: Charles Herrold and the First Radio Station. In 1909 — 10 years before licensed broadcasting and the first use of the word ‘radio’ — an obscure inventor living in the Santa Clara Valley created a broadcast station. His design was based on a radio-telephone and used a water-cooled microphone comprised of six carbon buttons in a telephone-like handset.

Show floor hours

Thursday, October 28 Noon to 6 p.m.
Friday, October 29 10 a.m. to 6 p.m.
Saturday, October 30 10 a.m. to 6 p.m.
Sunday, October 31 10 a.m. to 4 p.m.

Product Preview

Condenser mic
booth 1010
BCM 104:
The first product in the broadcast line, this condenser mic offers an independent, functionally-optimized design derived from 3D simulations. The large-diaphragm condenser capsule features a cardioid directional pattern with internally switchable proximity effect compensation. A second switch allows the sensitivity to be reduced by 14dB. The microphone headgrille twists off for quick cleaning. Optional, color-coded headgrilles are available. The BCM 104 has an elastic mount.
fax 860-434-3148


Compact microphone
DPA Microphones
booth 1342
This cardioid stereo kit provides stereo pickup capability in a small space. The 3521 includes two 4021 compact cardioid microphones matched within 2dB of frequency response, sensitivity and self-noise. Originally designed for use inside a piano, the mic pair can be used in other applications where space is limited or a low-profile is needed. The kit is supplied in a sturdy carrying case and includes a combination XY/ORTF holder, two gooseneck mounts and two magnet bases for mounting on metal surfaces. The mics use the same capsule as the standard series DPA 4011 microphone, but are pre-amplified using a built-in, miniaturized, thick-film-mounted FET-amplifier.
fax 303-823-5830


Bass traps
booth 1641
Measuring 2' x 4'9" x 4" thick, these traps are made with rigid fiberglass and metal instead of foam, so they are Class A fire-rated. They can be hung with picture frame wire or can be mounted on a microphone stand. A custom stand is also available. At 40Hz the absorption coefficient is above 0.50 when corner mounted.

Studio monitor
Dynaudio Acoustics
booth 326
The two-way active speaker is powered by two 50W amps and operates within a frequency response of 50Hz to 21kHz. The speaker was designed with a 6.7" woofer and 1" soft dome tweeter. The exterior has been redesigned, just as the drivers have undergone fine-tuning.
+45 87-427000
fax +45 87-427010


booth 602
This gate/compressor combines two noise gates and two soft/hard knee compressors with variable threshold limiting in a 1RU, four-channel toolbox. From the front panel, users may configure the unit as four stand-alone processors or as a stereo linked pair of compressor/limiters with a stereo linked pair of gates. Each channel may be operated as a hard or soft gate with switchable attenuation and LED indication of mode status. Frequency-selective gating is offered using variable low- and high-pass filters. Each channel combines an auto attack/release compressor with a threshold peak level limiter on the output, adjustable from 0dB to 16dB above system level. A high-resolution bar graph displays meter gain reduction and output level simultaneously. Balanced 4dB XLR in/out connectors are provided, with 1/4" jack key inputs.
fax 702-365-5145


Digital audio cable
Gepco International
booth 528
DS series:
This 110ohm digital audio, twisted-pair cable is available 24 and 26 gauge sizes and in multi-pair and single-pair configurations. The cable has been engineered for the highest bandwidth and performance requirements of high-resolution digital audio sample rates. All DS series cables are rated up to 25MHz to meet the AES3-2003 specifications. The cables feature minimal attenuation, low-jitter and a 110ohm impedance that remains stable when the cable is bent or flexed. The cable is more flexible than similar cable designs. This series replaces the previous generation of cables, the 5500 series.
fax 847-795-8770


Condenser mics
booth 1302
Pro series:
The Pro series line comprises 11 models. The Pro 31/Pro 31QTR, Pro 41 and Pro 61 all feature high-energy neodymium magnets, Magnalock switch design, two-stage ball-type headcase, gold-plated XLRM-type connector, and the AT8470 Quiet-Flex stand clamp plus a 5/8"-27 to 3/8"-16 threaded adapter. The Pro 31 cardioid dynamic mic is designed for close-up vocal performance and is available in two models for compatibility with consumer and pro electronics, Pro 31 (XLR-XLR cable) and Pro 31QTR (XLR-1/4" cable). The Pro 41 cardioid dynamic mic features a step-up design providing natural, full-range vocal reproduction. The Pro 61 hypercardioid dynamic mic offers extended frequency response and hypercardioid polar pattern. The Pro 63 cardioid dynamic mic features a high-energy neodymium magnet structure, a cardioid polar pattern and a two-stage headcase to reduce wind noise and popping. The Pro 24 stereo condenser mic offers a pair of cardioid elements in X-Y configuration provides the spatial impact and realism of a live sound field.
fax 330-686-0719


SPL meter
ATI-Audio Technologies
booth 422
This meter features a large analog meter for quick and accurate measurements from 32Hz to 10kHz with A and C weighted measurements with peak or averaging response. It includes a seven-range selector switch, calibration control and a test signal output. A 9V battery supplies power. A threaded Insert allows the meter to be mounted on a camera tripod. The unit measures 6.25" x 2.5" x 1.75".
fax 215-443-0330


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