Acoustics of Concert Halls and Rooms SOME BASICS OF ARCHITECTURAL ACOUSTICS Auditorium Acoustics Science of Sound, Chapter 23 Principles of Vibration and Sound, Chapter 11 Kimmel Center
SOUND FIELD p vs r log p vs log r Free field Reflections
Sound decay Sound decay in a 400 m3 classroom Sound pressure level as a function of time for that room
GROWTH AND DECAY OF REVERBERANT SOUND RT = K (volume / area) RT = 0.161 V/A (V in m3; A in m2 ) If room dimensions are given in feet, the formula may be written: RT= 0.049 V/A (V in ft.3 ; A in ft.2 )
Decay of reverberant sound and (b) are decay curves of sound pressure and sound level in a room with uniform energy distribution (c) shows different initial and final reverberation times (d) shows peaks due to prominent standing waves or room resonances
CALCULATING REVERBERATION TIME
CALCULATING REVERBERATION TIME
Desirable reverberation times for various sizes and functions Variation of reverberation time with frequency in good halls
McDermott Concert Hall (Dallas)
Orchestra Hall (Chicago)
Meyerhof Symphony Hall (Baltimore)
Walt Disney Concert Hall
Disney
Kimmel Center Auditorium
BACKGROUND NOISE CRITERIA
Important criteria for concert halls: Spatial impression Intimacy Early decay time Clarity “Warmth” Important criteria for concert halls:
Concert halls throughout the World