Last Updated: 20060822, mei
Sunday, October 8, 2:00 pm — 4:00 pm
Chair: Jan Voetmann, DELTA Acoustics and Vibration - Hoersholm, Denmark
P23-1 Pole-Zero Analysis of the Soundfield in Small Rooms at Low Frequencies—Jack Oclee-Brown, KEF Audio (UK) - Maidstone, Kent, UK
At low frequencies in small rooms the number of acoustic modes is sparse. In this region the sound field can be most easily modeled using the method of modal decomposition. From this it is possible to extract the transfer behavior of the room for different source and receiver positions and to determine the pole and zero locations. In this paper the locations of the poles and zeros are discussed, and it is demonstrated that the locations of the poles are independent of the source and receiver positions. The result of some room correction methods and other effects are shown in this context.
Convention Paper 6986 (Purchase now)
P23-2 Modeling of Loudspeaker Systems Using High-Resolution Data—Stefan Feistel, Wolfgang Ahnert, Ahnert Feistel Media Group - Berlin, Germany
The need for high-resolution loudspeaker data is evaluated in detail, particularly complex data in original impulse response or frequency response formats, and how a new data format proposed earlier can be used for storing this and other information required to adequately describe a complex loudspeaker system. Prediction results for several loudspeaker models are compared based on different spectral and spatial resolutions. Calculations are also compared against measurements for different loudspeaker types, such as multi-way loudspeakers, clusters, and line array systems. Finally, the advantages of more precise predictions are discussed with respect to increasing requirements regarding computer performance and data storage.
Convention Paper 6987 (Purchase now)
P23-3 Software Based Live Sound Measurements—Wolfgang Ahnert, Stefan Feistel, Alexander Miron, Enno Finder, Ahnert Feistel Media Group - Berlin, Germany
In previous publications the authors introduced the software based measurement system EASERA to be used for measurements with different excitation signals like Sweep, MLS or Noise. The actual approach extends the range of excitations to natural signals like speech and music. This paper investigates selected parameters such as frequency range, dynamic range, and fluctuation of the signal and the signal duration in order to reach conclusions about the conditions required to obtain results comparable with standard excitation signals. In this respect the limitations of the standard stimuli and the proposed natural stimuli are also discussed.
Convention Paper 6988 (Purchase now)
P23-4 Detection of Localized Sound Leaks in Walls and Their Effects on the Speech Privacy (Security) of Closed Rooms—Bradford Gover, John Bradley, National Research Council Canada - Ottawa, Ontario, Canada
A new speech privacy measurement procedure accurately indicates the degree of speech privacy at individual listening locations outside of a closed room, including near localized weak spots. To investigate the importance of various defects (such as penetrations, electrical outlets), they were introduced into a test wall dividing two reverberation rooms. For each configuration of the wall, the following sound transmission measurements were made from one room to the other: (i) a standard transmission loss test, (ii) the new speech privacy measurement procedure, and (iii) impulse response measurements to a highly-directional spherical microphone array. The results indicate the degree to which the various defects affect the speech privacy conditions and the extent to which they are detectable by the various methods.
Convention Paper 6989 (Purchase now)
