Course:Phys341 2020/Orpheum Theatre

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Orpheum Theatre Main Stage

The Orpheum Theatre is a music and theatre venue located in downtown Vancouver, Canada. Primarily, it is the home of Vancouver’s Symphony Orchestra. The theatre is a 2800 seat venue, originally a vaudeville house renovated for the Vancouver Symphony in the late 1970s.[1] Renovations were undertaken in order to optimize the venue’s interior for the sound needs of the orchestra. The reverberation time of produced sound was of utmost importance in designing the new interior, with a new layout designed to best improve acoustical quality. [2]

The Orpheum Theatre

The Orpheum Theatre has been the primary home of the Vancouver Symphony Orchestra for over four decades.[3] However, it was not originally constructed to serve as a concert hall, and as such, has major limitations in the quality of sound. Popular complaints regarding sound quality include excessive room noise, and orchestral balance- causing instruments or voices to appear as if their sound was emanating from elsewhere. The city has undertaken major renovations in order to try and curb these limitations, though complaints still remain. In measuring sound quality in the Orpheum today, two metrics have been prioritized- loudness and reverberation time.[4]

Loudness

Figure 1. Variations in sound strength within the concert hall

Loudness is the subjective perception of sound pressure, in which we order sounds from quiet to loud. The loudness of sound in a concert hall is very important as the obvious intention of any performance is to be heard. The quality of loudness can dramatically affect the perception of other acoustic qualities such as intimacy as it is difficult to appreciate these factors if the sound is not fully heard. Loudness in a concert hall may be objectively measured by the strength factor, G, in decibels. This is the measured sound pressure level at a position in the hall, relative to the sound level of the same source in a free field 10 m away. As seen in figure 1, in the Orpheum, loudness decreases significantly as one moves from the front to the back of the audience seating area. By the time one reaches the back of the audience area, the sound level as decreased by 3 dB, dramatically decreasing the audiences perception of the orchestra's sound. (OW)

Reverberation Time

Figure 2. Reverberation Time Diagram

Reverberation Time (RT)  is defined as the time it takes for sound energy to decay 60 decibels from its original level. Figure 2 demonstrates visually a simple graphing of this concept. Reverberation time is of great importance to music venues due to its influence on the quality of acoustics. Though the optimal reverberation time varies depending on the style of music or performance, convert halls generally have an RT between 1.8 and 2.2 seconds in mid-level frequencies.[5]

RT influences the quality of sound in a performance in impacting an audience’s ability to hear a specific sound at a certain time. For example, a lecture hall typically requires a shorter reverberation time in order to have speech more clearly decipherable. If the reflected sound is still audible when another word is spoken, it impacts the ability for audiences to understand what is said. If reverberation time is too short in a concert hall, tonal balance and volume will suffer.

The Orpheum Theatre has a reverberation time of the mid-frequency (250 Hz to 2 kHz) average Reverberation Time is 1.92 seconds (OW), and the average Early Decay Time is 1.77 (OW)

A 1994 study of sound quality in the Orpheum found that Early Decay Time in seats under the balcony were generally shorter than those seats in the balcony. [6] In concert halls, shorter EDT is often desirable as to improve clarity, but requiring a longer RT to provide a fuller, livelier texture to the music. In addition to the impact of the balcony overhang, the Orpheum's ceiling has a number of curved areas that contribute to focused reflection of sound in various areas.[7] Though the halls overall RT and EDT measurements fit into an acceptable range, it is the variation in quality that contribute to complaints over the venues sound quality.

References

  1. Bradley, J. S. "Acoustical analysis of the Orpheum Theatre." Canadian Acoustics 22, no. 3 (1994): 49-50.
  2. Bradley, John S. "Review of objective room acoustics measures and future needs." Applied Acoustics 72, no. 10 (2011): 713-720.
  3. M. Barron and L.-J. Lee. "Energy Relations in Concert Auditoria. I, J. Acoust." Soc. Am.(1988): 618-628
  4. Moore, Paul. "Movie palaces on Canadian downtown main streets: Montreal, Toronto, and Vancouver." Urban History Review/Revue d'histoire urbaine 32, no. 2 (2004): 3-20.

Citations:

  1. Moore, Paul (2004). "Movie palaces on Canadian downtown main streets: Montreal, Toronto, and Vancouver". Urban History Review. 32: 3–20.
  2. Moore, Paul (2004). ""Movie Palaces on Canadian downtown main streets: Montreal, Toronto, and Vancouver."". Urban History Review. 32: 3–20.
  3. Moore, Paul (2004). ""Movie palaces on Canadian downtown main streets: Montreal, Toronto and, Vancouver."". Urban History Review. 32: 3–20.
  4. Bradley, J.S. (1994). "Acoustical analysis of the Orpheum Theatre". Canadian Acoustics. 3: 49–50.
  5. Barron, Michael (1988). "Energy Relation in Concert Auditoria". Soc.Am: 618–628.
  6. Bradley, J.S. (1994). "Acoustical analysis of the Orpheum Theatre". Canadian Acoustics. 3: 49–50.
  7. Bradley, J.S. (1994). "Acoustical analysis of the Orpheum Theatre". Canadian Acoustics. 3: 49–50.