Last Updated: 20050816, mei
P20 - Sound Reinforcement
Monday, October 10, 1:00 pm — 3:00 pm
Chair: Wolfgang Ahnert, Acoustic Design Ahnert GmbH - Berlin, Germany
P20-1 Assessing the Suitability of Digital Signal Processing as Applied to Performance Audio such as In-Ear Monitoring Systems—Steve Armstrong, Keith Gordon, Betty Rule,, Gennum Corporation - Burlington, Ontario, Canada
In the sound reinforcement field, current in-ear monitor (IEM) systems provide a number of benefits over floor wedges including hearing protection, reduced stage volume, and improved coverage. However, new problems arise from occlusion caused by the tight earbud seal while old problems such as lack of personalization still remain. By applying digital signal processing (DSP) derived from the current state of the art in the hearing aid (HA) industry, these problems can be overcome. DSP is applied to both ambient microphones located at the users’ ears and the monitor audio feed. It provides multiband parametric equalization, compression, and limiting for each feed and ear separately, allowing for precise tailoring of the sound, including compensation for hearing loss.
Convention Paper 6630 (Purchase now)
P20-2 New Data Format to Describe Complex Sound Sources—Stefan Feistel, Software Design Ahnert GmbH - Berlin, Germany; Wolfgang Ahnert, Acoustic Design Ahnert - Berlin, Germany; Steffen Bock, Software Design Ahnert GmbH - Berlin, Germany
Originated by the evolution of modern sound systems and the resulting need to describe them formally, a new data format was developed to contain the mechanical, electronic, and acoustic properties of complex sound sources, such as loudspeaker clusters, column speakers or line arrays. The GLL (Generic Loudspeaker Library) format can utilize measurement data such as impulse responses or transfer functions directly, or include already postprocessed fractional-octave data. To conveniently manage the amount of data involved, a specialized storage algorithm was developed. Furthermore, a freely available software is presented that was created during the research work. It allows for utilizing these import and export functions as well as for investigating the data. As a part of the EASE acoustic simulation program, the software will allow loudspeaker manufacturers and users of acoustic prediction software to create and exchange complex loudspeaker data in a high-resolution format.
Convention Paper 6631 (Purchase now)
P20-3 The Significance of Phase Data for the Acoustic Prediction of Combinations of Sound Sources—Stefan Feistel, Software Design Ahnert GmbH - Berlin, Germany; Wolfgang Ahnert, Acoustic Design Ahnert GmbH - Berlin, Germany
Until today, only a few acoustic prediction software packages utilize complex directivity data to characterize sound sources, such as line arrays. This paper gives some theoretical background on the significance of phase data for the prediction of combinations of coherent sound sources. A mathematical model is introduced that allows evaluating the error ranges for several loudspeaker measurement methods. It is shown that, in contrast to what one would naively expect, the choice of the reference point for measuring complex data is rather irrelevant within given limits. These limits are derived based on the propagation equation for spherical waves. It is further shown analytically that the use of phase data reduces the measurement error to be expected by at least an order of magnitude.
Convention Paper 6632 (Purchase now)
P20-4 Simulation, Auralization, and Their Verification of Acoustic Parameters Using Line Arrays—Wolfgang Ahnert, Acoustic Design Ahnert GmbH - Berlin, Germany; Stefan Feistel, Software Design Ahnert GmbH - Berlin, Germany
An existing room with installed line arrays was investigated by means of corresponding measurements. Furthermore, in EASE4.1 a simulation of direct sound coverage as well as of the room impulse response has been done, to derive as a result sound levels and intelligibility measures. Here different approaches have been utilized including a statistic field approximation and the room acoustic algorithms of EASE AURA. Additionally the same acoustic parameters have been measured using the measurement software EASERA. The comparison of measured and simulated results showed a good correlation. To additionally confirm the similarity, a comparison of auralized files was performed which showed deviations audible only for experts.
Convention Paper 6633 (Purchase now)