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Anders Christian; Winsvold, Bjorn Downloaded from orbit.dtu.dk on: Sep 25, 2021 Simultaneous measurements of room-acoustic parameters using different measuring equipment? Halmrast, Tor; Gade, Anders Christian; Winsvold, Bjorn Published in: Acoustical Society of America. Journal Link to article, DOI: 10.1121/1.422575 Publication date: 1998 Document Version Publisher's PDF, also known as Version of record Link back to DTU Orbit Citation (APA): Halmrast, T., Gade, A. C., & Winsvold, B. (1998). Simultaneous measurements of room-acoustic parameters using different measuring equipment? Acoustical Society of America. Journal, 103(5), 3034-3034. https://doi.org/10.1121/1.422575 General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. Users may download and print one copy of any publication from the public portal for the purpose of private study or research. You may not further distribute the material or use it for any profit-making activity or commercial gain You may freely distribute the URL identifying the publication in the public portal If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. FRIDAY MORNING, 26 JUNE 1998 GRAND BALLROOMA&B~S!, 8:00 TO 9:00 A.M. Session 5aPLa Plenary Lecture Andrea Prosperetti, Chair Mechanical Engineering, Johns Hopkins University, 122 Latrobe Hall, 3400 North Charles Street, Baltimore, Maryland 21218 Chair’s Introduction—8:00 Invited Paper 8:05 5aPLa1. Acoustics of two-phase fluids and sonoluminescence. Robert I. Nigmatulin ~Ufa ~Bashkortostan! Branch of Russian Acad. of Sci., K. Marx Str. 6, Ufa 450000, Russia, [email protected]! The basic equations for dynamics of two-phase mixtures like gas–particle suspensions and bubbly liquids are presented. Heat and mass exchange phenomena near a drop, particle, and gas or vapor bubble are discussed. It is shown that these phenomena play an important role in propagation, attenuation, and amplification of sound waves and shock waves in gas–liquid systems, sometimes leading to paradoxical effects. The dynamics of a sonoluminescing bubble is discussed. There are two stages of the bubble oscillation process: The low Mach number stage when the velocity of the bubble interface is small compared with sound speed in the liquid, and the stage corresponding to the collapsing bubble’s compression, when the velocity of the interface may be larger than the sound speed. The analytic solution for the low Mach stage is presented. This solution provides the economical boundary condition around the bubble for an effective numerical code. FRIDAY MORNING, 26 JUNE 1998 CASCADE BALLROOM II ~W!, 7:20 TO 10:45 A.M. Session 5aAA Architectural Acoustics: Case Studies of Performance Spaces Jerald R. Hyde, Chair Consultant in Acoustics, Box 55, St. Helena, California 94574 Chair’s Introduction—7:20 Invited Papers 7:25 5aAA1. The Hong Kong Cultural Centre halls: Acoustical design and measurements. A. Harold Marshall, Johan L. Nielsen, and M. Miklin Halstead ~Acoust. Res. Ctr., Univ. of Auckland, New Zealand! The main performance spaces in the Hong Kong Cultural Centre comprise the Concert Hall, seating 2000 and the Grand Theatre seating 1700. The design of the former is derived from the Christchurch Town Hall which it develops in several important ways, while the latter is a lyric theatre/opera hall with several unique features which are described briefly in this paper. The Centre opened in 1989 following extensive commissioning measurements in the halls. Recently the opportunity has arisen to repeat the measurements using an improved technique in an attempt to document changes following a stage extension. Results from these measurements are compared with the earlier series in each hall. Marshall Day Associates, Auckland, New Zealand was responsible for the room acoustical design of these spaces. @The recent visit to Hong Kong was supported by the Acoustics Research Centre, the Hong Kong Cultural Centre, and the Marsden Fund administered by the Royal Society of New Zealand.# 7:45 5aAA2. Modern measurements, optimized diffusion, and electronic enhancement in a large fan-shaped auditorium. John P. O’Keefe ~Aercoustics Eng. Ltd., 50 Ronson Dr., Ste. 127, Toronto, ON M9W 1B3, Canada!, Trevor Cox ~Univ. of Salford, UK!, Neil Muncy ~Neil Muncy Assoc., Toronto, Canada!, and Steve Barbar ~LARES Assoc., Cambridge, MA! The Hummingbird Centre in Toronto Canada, formerly known as the O’Keefe Centre, is a 3000 seat fan-shaped auditorium, typical of the postwar era. Since it opened in 1960 it has been plagued by complaints about its acoustics. A LARES electronic enhancement system was proposed for the building and a feasibility study was carried out. Modern acoustical measurements lend 3032 J. Acoust. Soc. Am., Vol. 103, No. 5, Pt. 2, May 1998 16th ICA/135th ASA—Seattle 3032 credence to the years of complaints. Among other interesting findings, late energy ~Glate! is 10–20 dB lower than a traditional shoe-box-shaped concert hall. Such low levels of late energy explain, in part, the image shift and echoes that are found throughout the hall. A side wall echo threatened to compromise the proposed enhancement system. In an effort to reduce the echo, a crescent-shaped diffuser was developed using a BEM optimization routine. Four LARES mainframes are employed in the enhancement system with more than 280 front ported two-way loudspeakers, each of which can be addressed individually. The renovated acoustics have been well received by the owners, users, and patrons. Contributed Papers 8:05 Gewandhaus. The study explores Nikish’s response to the hall’s acoustic possibilities, and suggests reasons why a hall with a relatively dry acoustic 5aAA3. Recent acoustical measurements in the Christchurch Town could be pivotal in the orchestra’s then becoming a foremost interpreter of Hall Auditorium. A. Harold Marshall, Johan L. Nielsen, and M. Miklin the late Romantic repertoire. Halstead ~Acoust. Res. Ctr., Univ. of Auckland, Private Bag 92019, Auckland, New Zealand, [email protected]! 8:50 Two significant changes have occurred in the Christchurch Town Hall 5aAA6. Acoustical design and the characteristics of Sapporo Concert during 1996-97: the original seats have been replaced with a new type and Hall. Yasuhisa Toyota and Katsuji Naniwa ~Nagata Acoust., Inc., a new Rieger pipe organ has been installed behind the choir seats. A new Minami-Shinjuku-Hoshino Bldg. 8F, 5-23-13 Sendagaya, Shibuya-ku, comprehensive set of acoustic measurements has been made in the unoc- Tokyo, 151-0051 Japan, [email protected]! cupied hall. These are reported and compared in this paper with earlier Sapporo Concert Hall, with 2008 seats in the large hall and 453 seats measurements. A related study on the usefulness of C80 as a clarity mea- in the small hall, was opened on July 4, 1997. Both halls were designed sure in concert halls and which makes use of these results is reported in a for classical music, the large one mainly for orchestral music and the small companion paper. @This work is supported by the Marsden Fund adminis- one for chamber music and recitals. The large hall was designed with the tered by the Royal Society of New Zealand.# concept of the surrounded stage and ‘‘vineyard steps’’ seating arrange- ment like Philharmonic Hall in Berlin and Suntory Hall in Tokyo. The 8:20 emphasized points in acoustical design were as follows: ~1! Effective use of the ‘‘vineyard steps’’ walls which were introduced into the audience 5aAA4. Calculation and measurement of acoustic factors for the area to provide the effective early reflections; ~2! installation of the big Kirishima International Concert Hall. Tatsumi Nakajima ~Takenaka sound reflectors suspended above the stage area to provide the effective Res. and Development Inst., 5-1, 1-chome Ohtsuka, Inzai, Chiba, 270-13 early reflections to musicians and audience around the stage; ~3! introduc- Japan! and Yoichi Ando ~Kobe Univ., Rokkodai, Nada, Kobe, 657 Japan! tion of heavy material, 150-millimeters-thick concrete, into the main ceil- The Kirishima International Concert Hall was designed by architect F. ing to get enough response in the low frequencies. The small hall was Maki with Ando’s acoustic design theory. It opened on July 22, 1994. The designed as a typical shoebox hall with narrow width and high ceiling. 770 seat main hall which has a volume of 8475 m3 was primarily designed Acoustically tunable curtains were introduced to make the wide range of for chamber music. Computer simulations made it clear that the acoustical acoustical possibilities. The results of the acoustical design and its char- design of the main hall would be an optimum solution with a plan like a acteristics will be reported. leaf shape and a cross section like a bottom of a ship. These were solutions 9:05 which satisfied requirements for both acoustical and architectural design concepts of the main hall. Getting a low IACC sound field at the front seat 5aAA7. Acoustical renovation of The Opheum Theatre, Vancouver was most important. In order to get a low IACC, sound reflections from Canada. John P. O’Keefe ~Aercoustics Eng. Ltd., 50 Ronson Dr., Ste. the stage to the audience floor were examined and studied in the early 127, Toronto, ON M9W 1B3, Canada!, Gilbert A. Soulodre ~Commun. design processes. Calculation and measurement of acoustic factors of the Res. Ctr., Ottawa, ON K2H 8S2, Canada!, and John S. Bradley ~Natl. sound fields in the main hall show: ~1! the calculated and the measured Res. Council, Ottawa, ON K1A 0R6, Canada! IACCs are good in agreement, ~2! IACCs tended lower values of about 0.1 The Orpheum Theatre is a 2800 seat vaudeville house that was reno- than the calculated ones throughout the seats, and ~3! the number of re- vated for the Vancouver Symphony in the 1970s.
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