AES Berlin 2014
Engineering Brief EB2

EB2 - Papers Session 1


Monday, April 28, 15:00 — 17:00 (Estrel Hall C1)

Chair:
Christopher Kling, Klangkantine - Darmstadt, Germany

EB2-1 Auto Adaptation of the Mobile Device Characteristics for Various Acoustic ConditionsJozef Kotus, Gdansk University of Technology - Gdansk, Poland; Andrzej Ciarkowski, Gdansk University of Technology - Gdansk, Poland; Andrzej Czyzewski, Gdansk University of Technology - Gdansk, Poland
The proposed methodology of auto adaptation of the mobile device characteristics for various acoustic conditions was presented in the paper. The main purpose of this study was to determine the parameters of the acoustic path of the mobile device for both transmitting (speaker) and receiver (microphone). Results of the measurement characteristics of mobile devices were presented. Information about characteristics of the particular partials of the sound path were used to design and develop a technique of linearization of the device frequency response characteristics. Preliminary results obtained with the proposed methodology are presented. The performed research evolved into the design of an adaptive self-linearization method that compensates for the changing of acoustic conditions through continuous monitoring and regulating the audio settings.
Engineering Brief 136 (Download now)

EB2-2 The Sonic Characteristics of the Jazz Style Electric Bass GuitarBryan Martin, McGill University - Montreal, QC, Canada; Centre for Interdisciplinary Research in Music Media and Technology (CIRMMT) - Montreal, QC, Canada
The electric Jazz-style bass has long been established as a staple in jazz and popular music. This investigation seeks to measure and map the resonant, sonic, acoustic, and electromagnetic characteristics of the instrument and its constituent parts. The characteristics and constituents to be examined are the electromagnetic pickups, resonances in the body and neck, passive electronics, and electrical impedances. An analysis will examine their confluence and contributions to the resultant sound of the instrument. While much has been published concerning the electric guitar and its pickups, there has been very little published concerning solid-body bass guitars.
Engineering Brief 137 (Download now)

EB2-3 New Studio Strategies in Music Production—The Disappearing Gap between Engineer and ProducerChristopher Kling

In an industry of shrinking music production budgets, it is common that the audio engineer and music producer happen to be the same person. New technologies as well as new system designs in hardware and software further enforce this transition—not only in project/home studios. In addition to the risks of this development, there are also benefits: New production and studio strategies enable engineers to be more flexible to the changing demands of clients and artists while working more cost-effectively. This involves changes in common studio architecture and setup and a different recording workflow through the use of new technologies in DAWs, as well as less distinction between recording and mixing. A few specific examples and perspectives will be given.
Engineering Brief 138 (Download now)

EB2-4 Compensation of Crossover Region Overshoot in Multiband CompressionDavid Traore, Beats Electronics, LLC - Santa Monica, CA, USA; Joshua Atkins, Beats Electronics, LLC - Santa Monica, CA, USA; Andrei Krishkevich, Beats Electronics - Santa Monica, CA, USA; Adam Strauss, Beats Electronics, LLC - Santa Monica, CA, USA
Overshoot in the crossover region of multiband dynamic range compression (DRC) systems is an issue that is encountered in several audio applications such as hearing aids, audio mastering tools, and portable loudspeaker systems. This overshoot translates into a loss of overall loudness due to reduced post scale headroom, digital clipping, or allowable output above a chosen threshold. This paper introduces a gain compensation filter in the limiter gain computation path in each band, thus preserving the audio quality and loudness of the system. Furthermore, a couple of methods for calculating the optimal compensation filter is presented along with analysis of the two and three band DRC systems with and without the proposed solution.
Engineering Brief 139 (Download now)

EB2-5 Multiphysical Simulation Methods for Loudspeakers—A (Never-)Ending Story?Alfred Svobodnik, Konzept-X GmbH - Karlsruhe, Germany
Multiphysical simulations of loudspeakers have been investigated by scientific and industrial researchers for more than 40 years. At a first glance an electrodynamic loudspeaker seems to be a fairly simple assembly—a simple (sub-)system compared to typical applications of modern CAE methods. So where is the challenge? In detail! Besides strongly coupled different physical domains (electromagnetics, mechanics, acoustics, thermal transport, fluid dynamics ...), we also have to deal with path dependent dynamic effects and nonlinearities (including instabilities) in each domain. Additionally, materials with totally different behavior (and thus totally different material models to be used) and different joining techniques for each component are used as well. This paper will summarize challenges for realistic simulations and will discuss efficient solutions for daily usage in the industrial work flow of product development.
Engineering Brief 140 (Download now)

EB2-6 A Method for Comparison of Nonlinearities of Consumer Earphones Using Equalized StimuliFelix Fleischmann, Fraunhofer Institute for Integrated Circuits IIS - Erlangen, Germany; Jorgos Estrella, Fraunhofer Institute for Integrated Circuits IIS - Erlangen, Germany; Jan Plogsties, Fraunhofer Institute for Integrated Circuits IIS - Erlangen, Germany
Comparison of nonlinearities between different earphone models is not directly possible due to their different sensitivities and the high dynamics in the transducer's frequency response. Also, nonlinearities are highly dependent on the level of the excitation signal. An approach to overcome these differences and allow for fair comparison is proposed. The method is based on filtering commonly used stimuli like pink sweeps with a linear correction filter. This filter is obtained by a measurement at low input levels where the transducer shows linear behavior. The nonlinear response is then measured at different levels and THD is computed. In this way the non-linearity or different transducers can be compared directly. Some examples demonstrating the performance of consumer grade earphones are presented and discussed. The results show that nonlinearities mainly appear for low frequency excitation.
Engineering Brief 141 (Download now)

EB2-7 Design and Development of Auralization Room at Edinburgh Napier UniversityElena Prokofieva, Edinburgh Napier University - Edinburgh, UK; C. Luciani, Edinburgh Napier University - Edinburgh, Scotland, UK; I. McGregor, Edinburgh Napier University - Edinburgh, Scotland, UK
The auralization room was designed as a joint project between School of Engineering and Built Environment and the School of Computing of Edinburgh Napier University. The interior acoustic design specialists conducted the acoustic design of the auralization room, while the expert in computing provided the electronic systems. The room is planned to be used for various purposes, for example on the simulation of sound insulation of the partitions for proposed developments where the trial process is unrealistic under the real circumstances.
Engineering Brief 142 (Download now)

EB2-8 Comparative Results between Loudspeaker Measurements Using a Tetrahedral Enclosure and Other MethodsGeoff Hill, Hill Acoustics Limited - Leigh on Sea, Essex, UK
A major problem for the loudspeaker and transducer industries throughout the world, is an inability to rely upon measurements routinely exchanged between suppliers and customers. This paper updates "Consistently Stable Loudspeaker Measurements Using a Tetrahedral Enclosure" - EB4-7 published in 2013, with comparative measurements using results by other people, equipment and methods: Small IEC Baffle in Anechoic Chamber and Large IEC Baffle Outside vs a TTC 350. These Test Chambers give us the capability to approach "Design Quality" measurements easily throughout the entire supply chain, reducing errors and improving quality whilst driving down the cost of measurement.
Engineering Brief 143 (Download now)


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