anderson, bittick of fame... · 2013. 5. 29. · 5/12/2008 1 josh anderson case study #4 lisa...
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5/12/2008
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CASE STUDY #4Josh Anderson Lisa Bittick BUILDING DESCRIPTION
BUILDING DESCRIPTION
Architectural Acoustics, 138
BUILDING DESCRIPTION
The Lionel Hampton Recital Hall is designed with angled side walls and ceiling profile and wall baffles to create a reflected sound path.
The corner of the site has steady traffic causing linear noise on two sides of the building.
Fraternity & Sorority houses, the Administration Building, and other school buildings cause point source noise on three sides of the building.
Fortunately, the auditorium is situated on the back side of the building, where the parking lot, which is at a much lower elevation, is surrounded by landscape.
The mass of the masonry building on the north and west sides, in addition to the fact that there are no windows to the auditorium wall, acts as a barrier to noise.
Site Sound Evaluation
PERFORMANCE ANALYSIS
Building Acoustic Zoning
PERFORMANCE ANALYSIS
Classrooms 36 dB Faculty Studios 40 dBAuditorium 35‐40 dBMusic Practice Rooms 44 dB
Noise Isolation Class Ratings for Music Rooms
Architectural Acoustics, Egan
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Materials & Absorption
PERFORMANCE ANALYSIS
Absorption CalculatedSurface Material Area Coefficient Absorption
(sq. ft.) (Average of all frequency Hz)
Stage Floor Wood Parquet 735 0.10 73.50Auditorium Aisles Cork Tile 446 0.03 13.38Auditorium Floor Tile 1800 0.03 54.00
Seats Upholstered 1800 0.62 1116.00
Walls Wood Wainscot 800 0.16 128.00 Walls Gypsum/Plaster 1400 0.07 98.00Walls Acoustic Tile 2120 0.55 1166.00
Doors Wood 252 0.03 7.56
Ceiling Gypsum/Plaster 2050 0.07 143.50 Ceiling Acoustic Tile 1780 0.55 979.00
A = ∑Sa, where ‘a’ is the coefficient of absorption, ‘S’ is area in square ft., and ‘A’ is absorption in Sabins
TOTAL ABSORPTION 3778.94 Sabins
TR = K x V/∑A, where ‘K’ is the constant 0.05, and ‘V’ is volume in cubic ft., and ‘TR’ is reverberation time
VOLUME: 73,600 cubic ft. 0.05 x 73,600/3778.94
TOTAL REVERBERATION TIME 0.97 Seconds
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Reverberation & Performance Evaluation
PERFORMANCE ANALYSIS
MEEB, 772
With a reverberation time of 0.97, the hall is pretty good for small ensembles, which is consistent with the personal evaluation of the space during a performance.
Scale Model: 1/8” = 1’‐0”
PERFORMANCE ANALYSIS
Model Laser Reflection Data
PERFORMANCE ANALYSIS
The image above is a composite of 15 laser tests representing direct and reflected sound. Dark red indicates the lower levels of sound, pink indicates greater levels of sound, and white indicates the highest levels of sound. Dark grey areas may indicate dead spots, however, they are not near seating. The entire auditorium is saturated with sound.
PERFORMANCE ANALYSIS
• In spite of the building being in a noisy area, the recital hall is relatively shielded from outside noise.
• Inside the building, the acoustic zoning is complementary to the minimum background noise requirements of the recital hall.
• The reflective and absorptive properties of the materials inside the recital hall currently provide a reverberation time sufficient for small performances.
• Laser tests in the model indicate that there is an even distribution of sound throughout the hall.
• According to the musicians who perform in the recital hall, it is the best performance space on campus because of the clarity of the sound that allows musicians to hear each other clearly.
BUILDING REDESIGN
• If the reverberation time is increased, the hall will be more suitable for symphonic music, yet still be in the range for small ensemble jazz and chamber music.
• To increase reverberation time, we propose a reduction in the absorbency of the ceiling material—substituting gypsum/plaster and acoustic tiles for wood paneling.
• Hinged, moveable hollow‐core wood wall baffles attached at 8’ above the seating increase reflectivity and allow tuning of the hall. When the baffles are fully extended, the volume of the space decreases—reducing reverberation time.
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BUILDING REDESIGN
Gypsum/plaster replaced with wood paneling
Adjustable hollow‐core wood baffles
Absorption CalculatedSurface Material Area Coefficient Absorption
(sq. ft.) (Average of all frequency Hz)
Stage Floor Wood Parquet 735 0.10 73.50Auditorium Aisles Cork Tile 446 0.03 13.38Auditorium Floor Tile 1800 0.03 54.00
Seats Upholstered 1800 0.62 1116.00
Walls Wood Wainscot 800 0.16 128.00 Walls Gypsum/Plaster 280 0.07 19.60Walls Acoustic Tile 2120 0.55 1166.00Walls Hollow‐core Wood 1120 0.03 33.60
Doors Wood 252 0.03 7.56
Ceiling Wood Panel 3830 0.03 191.50
REDESIGN TOTAL ABSORPTION 2803.14 Sabins
VOLUME: 73,600 cubic ft. (PANELS CLOSED) 0.05 x 73,600/2803.14
TOTAL REDESIGNED REVERBERATION TIME 1.31 Seconds
Materials & Absorption
REDESIGN PERFORMANCE ANALYSIS
VOLUME: 71,345 cubic ft. (PANELS OPENED) 0.05 x 71,345/2803.14
TOTAL REDESIGNED REVERBERATION TIME 1.27 Seconds
REDESIGN PERFORMANCE ANALYSIS
• The initial reverberation time in the recital hall was 0.97.
• After the redesign, there is a range of reverberation times from 1.27 – 1.31, made possible by the adjustable baffles.
• The recital hall is still appropriatefor Jazz and Chamber music, but it nowalso is appropriate for some Symphonicmusic due to tuning capability.
• The Lionel Hampton Recital Hall is favored by musicians on campus because of its existing design for acoustic performance. A few alterations and additions improve on the existing design and allow the acoustics to be adjusted to achieve a range of reverberation times.