AES Rome 2013
Paper Session P6

P6 - Recording and Production

Sunday, May 5, 09:00 — 13:00 (Sala Carducci)

Alex Case, University of Massachusetts—Lowell - Lowell, MA, USA

P6-1 Automated Tonal Balance Enhancement for Audio Mastering ApplicationsStylianos-Ioannis Mimilakis, Technological Educational Institute of Ionian Island - Lixouri, Greece; Konstantinos Drossos, Ionian University - Corfu, Greece; Andreas Floros, Ionian University - Corfu, Greece; Dionysios Katerelos, Technological Educational Institute of Ionian Island - Lixouri, Greece
Modern audio mastering procedures are involved with the selective enhancement or attenuation of specific frequency bands. The main reason is the tonal enhancement of the original / unmastered audio material. The aforementioned process is mostly based on the musical information and the mode of the audio material. This information can be retrieved from a listening procedure of the original stimuli, or the correspondent musical key notes. The current work presents an adaptive and automated equalization system that performs the aforementioned mastering procedure, based on a novel method of fundamental frequency tracking. In addition to this, the overall system is being evaluated with objective PEAQ analysis and subjective listening tests in real mastering audio conditions.
Convention Paper 8836 (Purchase now)

P6-2 A Pairwise and Multiple Stimuli Approach to Perceptual Evaluation of Microphone TypesBrecht De Man, Queen Mary University of London - London, UK; Joshua D. Reiss, Queen Mary University of London - London, UK
An essential but complicated task in the audio production process is the selection of microphones that are suitable for a particular source. A microphone is often chosen based on price or common practices, rather than whether the microphone actually sounds best in that particular situation. In this paper we perceptually assess six microphone types for recording a female singer. Listening tests using a pairwise and multiple stimuli approach are conducted to identify the order of preference of these microphone types. The results of this comparison are discussed, and the performance of each approach is assessed.
Convention Paper 8837 (Purchase now)

P6-3 Comparison of Power Supply Pumping of Switch-Mode Audio Power Amplifiers with Resistive Loads and Loudspeakers as LoadsArnold Knott, Technical University of Denmark - Kgs. Lyngby, Denmark; Lars Press Petersen, Technical University of Denmark - Kgs. Lyngby, Denmark
Power supply pumping is generated by switch-mode audio power amplifiers in half-bridge configuration, when they are driving energy back into their source. This leads in most designs to a rising rail voltage and can be destructive for either the decoupling capacitors, the rectifier diodes in the power supply or the power stage of the amplifier. Therefore precautions are taken by the amplifier and power supply designer to avoid those effects. Existing power supply pumping models are based on an ohmic load attached to the amplifier. This paper shows the analytical derivation of the resulting waveforms and extends the model to loudspeaker loads. Measurements verify that the amount of supply pumping is reduced by a factor of four when comparing the nominal resistive load to a loudspeaker. A simplified and more accurate model is proposed and the influence of supply pumping on the audio performance is proven to be marginal.
Convention Paper 8838 (Purchase now)

P6-4 The Psychoacoustic Testing of the 3-D Multiformat Microphone Array Design and the Basic Isosceles Triangle Structure of the Array and the Loudspeaker Reproduction ConfigurationMichael Williams, Sounds of Scotland - Le Perreux sur Marne, France
Optimizing the loudspeaker configuration for 3-D microphone array design can only be achieved with a clear knowledge of the psychoacoustic parameters of reproduction of height localization. Unfortunately HRTF characteristics do not seem to give us useful information when applied to loudspeaker reproduction. A set of psychoacoustic parameters have to be measured for different configurations in order to design an efficient microphone array recording system, even more so, if a minimalistic approach to array design is going to be a prime objective. In particular the position of a second layer of loudspeakers with respect to the primary horizontal layer is of fundamental importance and can only be based on the psychoacoustics of height perception. What are the localization characteristics between two loudspeakers situated in each of the two layers? Is time difference as against level difference a better approach to interlayer localization? This paper will try to answer these questions and also justify the basic isosceles triangle loudspeaker structure that will help to optimize the reproduction of height information.
Convention Paper 8839 (Purchase now)

P6-5 A Perceptual Audio Mixing DeviceMichael J. Terrell, Queen Mary University of London - London, UK; Andrew J. R. Simpson, Queen Mary University of London - London, UK; Mark B. Sandler, Queen Mary University of London - London, UK
A method and device is presented that allows novice and expert audio engineers to perform mixing using perceptual controls. In this paper we use Auditory Scene Analysis [Bregman, 1990, MIT Press, Cambridge] to relate the multitrack component signals of a mix to the perception of that mix. We define the multitrack components of a mix as a group of audio streams, which are transformed into sound streams by the act of reproduction, and which are ultimately perceived as auditory streams by the listener. The perceptual controls provide direct manipulation of loudness balance within a mixture of sound streams, as well as the overall mix loudness. The system employs a computational optimization strategy to perform automatic signal gain adjustments to component audio-streams, such that the intended loudness balance of the associated sound-streams is produced. Perceptual mixing is performed using a complete auditory model, based on a model of loudness for time-varying sound streams [Glasberg and Moore, J. Audio Eng. Soc., vol. 50, 331-342 (2002 May)]. The use of the auditory model enables the loudness balance to be automatically maintained regardless of the listening level. Thus, a perceptual definition of the mix is presented that is listening-level independent, and a method of realizing the mix practically is given.
Convention Paper 8840 (Purchase now)

P6-6 On the Use of a Haptic Feedback Device for Sound Source Control in Spatial Audio SystemsFrank Melchior, BBC Research and Development - Salford, UK; Chris Pike, BBC Research and Development - Salford, York, UK; Matthew Brooks, BBC Research and Development - Salford, UK; Stuart Grace, BBC Research and Development - Salford, UK
Next generation spatial audio systems are likely to be capable of 3-D sound reproduction. Systems currently under discussion require the sound designer to position and manipulate sound sources in three dimensions. New intuitive tools, designed to meet the requirements of audio production environments, are needed to make efficient use of this new technology. This paper investigates a haptic feedback controller as a user interface for spatial audio systems. The paper will give an overview of conventional tools and controllers. A prototype has been developed based on the requirements of different tasks and reproduction methods. The implementation will be described in detail and the results of a user evaluation will be given.
Convention Paper 8841 (Purchase now)

P6-7 Audio Level Alignment—Evaluation Method and Performance of EBU R 128 by Analyzing Fader MovementsJon Allan, Luleå University of Technology - Piteå, Sweden; Jan Berg, Luleå University of Technology - Piteå, Sweden
A method is proposed for evaluating audio meters in terms of how well the engineer conforms to a level alignment recommendation and succeeds to achieve evenly perceived audio levels. The proposed method is used to evaluate different meter implementations, three conforming to the recommendation EBU R 128 and one conforming to EBU Tech 3205-E. In an experiment, engineers participated in a simulated live broadcast show and the resulting fader movements were recorded. The movements were analyzed in terms of different characteristics: fader mean level, fader variability, and fader movement. Significant effects were found showing that engineers do act differently depending on the meter and recommendation at hand.
Convention Paper 8842 (Purchase now)

P6-8 Balance Preference Testing Utilizing a System of Variable Acoustic ConditionRichard King, McGill University - Montreal, Quebec, Canada; The Centre for Interdisciplinary Research in Music Media and Technology - Montreal, Quebec, Canada; Brett Leonard, McGill University - Montreal, Quebec, Canada; The Centre for Interdisciplinary Research in Music Media and Technology - Montreal, Quebec, Canada; Scott Levine, McGill University - Montreal, Quebec, Canada; The Centre for Interdisciplinary Research in Music Media and Technology - Montreal, Quebec, Canada; Grzegorz Sikora, Bang & Olufsen Deutschland GmbH - Pullach, Germany
In the modern world of audio production, there exists a significant disconnect between the music mixing control room of the audio professional and the listening space of the consumer or end user. The goal of this research is to evaluate a series of varying acoustic conditions commonly used in such listening environments. Expert listeners are asked to perform basic balancing tasks, under varying acoustic conditions. The listener can remain in position while motorized panels rotate behind a screen, exposing a different acoustic condition for each trial. Results show that listener fatigue as a variable is thereby eliminated, and the subject’s aural memory is quickly cleared, so that the subject is unable to adapt to the newly presented condition for each trial.
Convention Paper 8843 (Purchase now)

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REGISTRATION DESK May 4th 09:30 – 18:30 May 5th 08:30 – 18:30 May 6th 08:30 – 18:30 May 7th 08:30 – 16:30
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AES - Audio Engineering Society