AES Dublin Engineering Brief EB05: Loudspeakers and Assistive Technologies

AES Dublin 2019
Engineering Brief EB05

EB05 - Loudspeakers and Assistive Technologies

Friday, March 22, 16:00 — 17:00 (Meeting Room 3)

Kirsten Hermes, University of Westminster - London, UK

EB05-1 Comparison of Horn Drivers’ Nonlinear Distortion Measured by Different MethodsAlexander Voishvillo, JBL/Harman Professional Solutions - Northridge, CA, USA; Balazs Kakonyi, Harman Professional Solutions - Northridge, CA, USA; Brian McLaughlin, Harman Professional Solutions - Northridge, CA, USA
Multitone and log-sweep testing signals at progressively increasing levels were applied to a horn driver to obtain a nonlinear response. Musical signals were also applied to the driver. The acoustical signal was received at the throat of the horn and at a 1-meter distance from the horn in a 2-Pi anechoic chamber. The levels of the applied signals were incremented in 3 dB voltage steps. The initial horn driver response was corrected to provide maximum flatness and passed through a high-pass filter. Auralization examples and graphic material are demonstrated. The next stage of the research will involve subjective listening tests with signals obtained from measurements and from nonlinear models of horn driver.
Engineering Brief 516 (Download now)

EB05-2 New Engineering Method for Design and Optimization of Phasing Plug and Dome-Shaped Compression Chamber of Horn DriversAlexander Voishvillo, JBL/Harman Professional Solutions - Northridge, CA, USA
In this work an accurate analytical solution is found for the sound field in a dome-shaped compression chamber. This simplifies the design and optimization of the compression chamber’s annular exits to suppress high-frequency air resonances. In earlier works by other authors, the solution is also found in spherical coordinates. For low-curvature chambers, an approximation in the form of Bessel function summation was used. For high-curvature compression chambers an analytical approximation did not work and FEA had to be used. The new proposed method is based on Mehler-Dirichlet analytical integral presentation of Legendre functions. This approach handles high-curvature dome chambers and does not require using numerical methods. An evaluation of this new method’s applicability to chambers with various different curvatures was implemented.
Engineering Brief 517 (Download now)

EB05-3 Conception of an IP-based Broadcast Infrastructure Considering SMPTE 2110 Using the Example of an Transmedia Teleshopping TV StationNorbert Wilinski, HSE24 - Ismaning, Germany
A future-proof broadcast infrastructure is critical to the success of a live TV channel. In addition to the widespread TV formats, content must also be produced for e-commerce and social media; this is especially true for teleshopping. The production environment has to be designed flexibly in order to adapt it quickly to changing market conditions. The simultaneous production for TV and social media must be just as possible as the successive work for various media, if possible without loss of time due to technical modifications. In addition, it is particularly important in teleshopping to make the course of the programs very variable and to adapt to the interaction of the audience. There is no way around an IP-based solution, but for reasons of transmission security, conventional approaches must continue to be taken into account. SMPTE 2110, Professional Media Over Managed IP Networks, introduces a solution specifically designed for live broadcasting. A concept is presented that further develops a classically designed broadcast infrastructure based on IP.
Engineering Brief 518 (Download now)

EB05-4 Education and Assistive Technology for Blind and Visually Impaired Musicians, Presenters or Authors of Radio Plays and Broadcast ProgramsMarcus C. Diess, StudioGuard - Salzburg, Austria
Many visually impaired people are predestined to work in any field of audio-production, in particular musicians with technical ambitions, authors, and presenters. Blind people often own outstanding analytic hearing to orientate in the spatial environment but require special teaching methods and assistive aids, because they cannot read screens, displays, and level-meters of studio hard-and software. Taking first steps into audio work of any kind are difficult for young blind people due to missing opportunities and professional support. Audio hard- and-software is far from barrier-free, but there are first successful attempts made to solve barriers. Such valuable efforts and an approach for teaching methods are revealed in this paper, reporting existing possibilities, and appealing to increase efforts in education opportunities for visually impaired. There is a quite remarkable number of highly professional blind musicians and sound producers, who prove that a blind person can have a career in the performing arts or music industry and take part in society as everybody else does. Methods for barrier free audio lectures for v.i. and blind people will be presented after an introduction with some general facts about visual impairment that have to be known by the reader for better comprehension of the topic. The intention is to encourage and empower visually impaired and blind people to claim participation in audio production, broadcast or even the movie industry´s new departments for audio description for visually impaired. I question the status quo and offer first solutions, improvements and research based on 30 years of practical audio work and 14 years partly awarded work with visually impaired music and radio enthusiasts. This paper is an excerpt and cannot claim being perfect in the solutions offered, as this field of research only just has begun. My intention is to share personal experience and ideas to encourage colleagues and audio professionals to go further and improve what´s already here in that context. To keep the text fluent and comprehensive the phrase “blind” stands for every kind of visual impairment (v.i.).
Engineering Brief 519 (Download now)

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