AES Tokyo Convention 2009
Paper Session A3

A3 — Room Acoustics

Friday, July 24, 16:00 — 17:20
Chair: Akira Omoto (Kyushu University)

A3 - 1   Multichannel Studio Design utilizing Modal Summation Method and First Reflection Sounds. - A Practical Example; Acoustic Design of NHK's CP604 Studio -

Masataka NAKAHARA (SONA), Makoto MORITA (NHK), Ryota ONO (NHK), Iwao BANNO (NHK), Akira FUKADA (NHK), Junichi MIKAMI (NHK), Ikuko SAWAYA (NHK)
In designing a fine multichannel monitoring environment, `low frequency control' and `wide listening area with natural playback sounds' are the important keys. In this paper, three practical design strategies are introduced to realize these keys. The first strategy is a calculation technique of modal analysis using `modal summation method.' It can predict low frequency properties of a rectangular room with less modeling/computing load. The second strategy is an active reflection control. It is a technique to improve low frequency responses by adding reflection sounds. The third strategy is a DFR (Decorrelated First Reflections). It is a design method of time response using early reflections actively. These strategies are introduced through a real design project, multichannel mixing room of NHK's CP604 Studio. Both calculated and measured data for the project shows good responses to demonstrate usefulness of the design methods proposed here.

A3 - 2   The architectural acoustic design and the system design of NHK HD520 postproduction studio.

Ryota ONO (NHK Broadcast Engineering Department Production Operation Center)
The loudspeaker setup was compliant with ITU-R BS775-1. Excellent architecture acoustics characteristic. HD520 employed cutting-edge system machine. HD520 was designed for the high quality works. I do presentation of HD520 about that acoustics characteristic and the system construction

A3 - 3   A basic study on the effect upon room acoustics by a multi-layered diffuser with different sized cylinders in random distribution

Yasushi Satake, Hideo Tsuru, Kazuhiro Makino, Yasuhiro Sakiyama, Shinji Ohashi, Hiroshi Ohyama (Nittobo Acoustic Engineering Co., Ltd.)
A basic study on a multi-layered diffuser composed with different sized cylinders in random distribution for a diffused reflection mechanism in small rooms is examined. This paper shows the result of the study on the effect upon room acoustic characteristics, especially focused on the eigenmodes at low frequency, the characteristics of diffused reflection, and the sound absorption characteristics of the diffuser. The full and 1/5 scale model experiments and the simulation using the FDTD (Finite Difference method in Time Domain) are used for this investigation.

A3 - 4   Evaluation of low frequency properties in small rooms using eigenmode calculation. -Examination of room shapes by an index N and hearing impression test-

Eri Takayama (SONA, Nihon University), Toshiki Hanyu (Nihon University), Hoshi Kazuma (Nihon University), Masataka Nakahara (SONA)
In acoustic design for small and medium-sized rooms, it is important to control low frequencies. But conventional evaluations methods are not suitable to make objective evaluation to find the only correct answer. In this study, a new evaluation method is proposed which has conventional mode density and effective mode density, represented by an index N, incorporated for mode evaluations. Use of the index N enables SPL deviation and degeneracy to be evaluated with simple numeric values. Moreover listening examination can be also carried out by auralization of room response.

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Last modified: Mon Jun 22 20:47:56 2009