Most of the Russian cinema halls were designed and built in the past for one channel sound reproduction. Now they are old fashioned and not popular with the public. It is well understood by the owners of the movie theatres that only modern rooms with multi-channel sound reproduction may be profitable. Acoustic design of 11 existing movie theatres (19 halls) was done during the last 2 years. The main parts of this design are: architectural acoustics of the rooms, sound insulation of the room's surfaces, noise control of ventilation systems, acoustic computer modeling of the loudspeaker systems for the screen and surround sound channels. There are presented the results of this design and the acoustic measurements have been done in the renovated halls. Some general tendencies for the renovation of the existing movie theatres have been estimated.
Convention Paper 5598

14:30 h
P2 Quality Criteria for the Sound System in the New Weimar Hall in Weimar, Germany - Ernst-Jo. Völker, Wolfgang Teuber, Institute for Acoustic and Building Physics, Oberursel, Germany

The very famous old Weimar hall was replaced by a new building with a concert hall in 1999. The new hall is also used as a multi-purpose hall for various activities such as concerts, musicals, pop concerts and conferences. The media design includes sound and video with computer based connections. The hall contains a sound system with hidden speakers above the stage and in the back part of the hall although the ceiling is about 12 meters high. The reverberation time of the hall is approximately 1.7 s in a closed smaller room compared to around 2.2 s in a more open space created by moving walls. The sound system was designed for the long reverberation time. In addition, the Weimar Hall houses a conference center for which the sound system also had to be designed. The different systems are connected through a digital routing system based on fiber optics, including the control rooms. This hall is now used for many events. The paper will describe results and experiences.
Convention Paper 5599

15:00 h
P3 A Mobile for Classical Recording – Ben Kok¹, Erdo Groot² - ¹Dorsserblesgraaf, Eindhoven, Netherlands; ²Polyhymnia International B.V., Baarn, Netherlands

High quality monitoring is hard to achieve in any confined space. This is particularly true in mobile recording trucks, due to the extremely limited space. This paper describes the design of such a truck where the requirement was high quality monitoring in 5.1 format, suited for classical recording. The design shows that the limited space in a truck does not imply that there is no room for acoustic treatment. Measurements in the completed truck show that an accurate monitoring environment has been realized and the acoustic qualities are not hindered by the limited dimensions Considerations on the choice of recording equipment as well as the experiences in its first year of use will be discussed.
Convention Paper 5600

15:30 h
P4 2-Bus Conference System for the European Central Bank (ECB), Frankfurt – Wolfgang Teuber, Ernst Völker, Institute for Acoustic and Building Physics, Oberursel, Germany

In the European Central Bank (ECB) in Frankfurt, new conference and press conference rooms with audio and media-technical equipment will be outlined and described. Conference systems, with more than 150 delegate stations, spread over 3 rooms and including two separate audio buses can be used for e.g. presidential or participant positions. Using separate controls at the mixing desk, various frequency responses and separate limiters, each station is capable of individual settings. The operation procedure is carried out PC-controlled through a touch screen with the possibility of storing system configurations. In each conference room compact loudspeaker boxes with good frequency response are mounted above the perforated surface of the ceiling. Before installation, tests and verifications were carried out through the program Modeler to check the acoustical transmission of ceiling material and to calculate sound fields. Media technical installations were integrated with video projection, cable and glass fiber connections to ensure a link to O.B. Vans as well as to radio/TV stations over existing broadband fiber networks. Concepts, design, measurement results and experiences will be presented.
Convention Paper 5601

16:00 h
P5 How Many Subwoofers are Enough? – Todd Welti, Harman International, Northridge, CA, USA

From an intuitive standpoint, putting a large number of subwoofers at different locations in a room might seem likely to excite room modes in a more “balanced” manner, as compared to a single subwoofer. This idea has particular appeal where there is not a single listening location, but rather a listening area. In this case one looks for consistency of acoustical response with in this area. Typical approaches to this problem involve exciting all modes evenly, or trying not to excite modes at all. With this in mind, an investigation was made to determine if using a large number of subwoofers is advantageous, and in particular what configurations give the best results. Several interesting and surprising results were uncovered along the way.
Convention Paper 5602

16:30 h
P6 Implementation and Visualization of Edge Diffraction with Image-Source Method – Ville Pulkki, Tapio Lokki, Lauri Savioja, Helsinki University of Technology, Espoo, Finland

Traditional image-source method for room acoustic modeling neglects both diffraction and diffusion. In this study the image-source method is evolved to also include edge diffraction as diffractive image sources. Methods to find diffracting edges from a geometric model of a room, and to visualize diffracted image sources are presented. Issues to limit computational complexity and memory usage in image-source method are reviewed and implemented. Diffractive image sources are visualized for two test cases, and impulse responses are calculated and compared with measured ones.
Convention Paper 5603

17:00 h
P7 Relationships between Speech Intelligibility Measures for Sound Systems – Peter Mapp, Ams-PeterMapp, Colchester, UK

A number of metrics exist to measure the potential speech intelligibility performance of a sound system. Most of these are derived from techniques developed for assessing natural speech intelligibility in auditoria rather than directly for sound systems whose acoustic characteristics and performance are highly frequency dependent. The paper compares measurements made on 81 sound systems that covered a wide variety of applications and acoustic environments. It was found that intelligibility metrics such as STI, RaSTI, C50 and C80 showed a high degree of inter correlation whereas surprisingly other measures such as RT60, EDT and % Alcons showed little or no correlation.
Convention Paper 5604