An Acoustical Study of An Acoustical Study of the the
Salt Lake TabernacleSalt Lake TabernacleSarah RollinsSarah Rollins
Timothy W. LeishmanTimothy W. Leishman
Acoustics Research GroupAcoustics Research GroupDepartment of Physics and Department of Physics and
AstronomyAstronomyBrigham Young UniversityBrigham Young University
147147thth Meeting of the Meeting of the Acoustical Society of AmericaAcoustical Society of America
May 25, 2004May 25, 2004
OverviewOverview
BackgroundBackground MeasurementsMeasurements ResultsResults ConclusionsConclusions Further WorkFurther Work
MotivationsMotivations
Characterize the acousticsCharacterize the acoustics Modern equipment and techniquesModern equipment and techniques Benchmark measurementsBenchmark measurements
Spatial variation of parametersSpatial variation of parameters Hall geometryHall geometry Spatial statisticsSpatial statistics
MeasurementsMeasurements SourcesSources
Dodecahedron loudspeakerDodecahedron loudspeaker Sound reinforcement systemSound reinforcement system
ReceiversReceivers Omnidirectional microphoneOmnidirectional microphone Multi-pattern microphoneMulti-pattern microphone KEMARKEMAR
MeasurementsMeasurements Maximum Length SequenceMaximum Length Sequence
Source PositionsSource Positions
Early Decay TimeEarly Decay Time
Color Range Beg. Range End Percent 2.00 2.25 0.0 2.25 2.50 0.0 2.50 2.75 0.1 2.75 3.00 0.2 3.00 3.25 2.8 3.25 3.50 12.3 3.50 3.75 12.4 3.75 4.00 16.8 4.00 4.25 23.9 4.25 4.50 14.5 4.50 4.75 5.5 4.75 5.00 3.8 5.00 5.25 3.1 5.25 5.50 3.3 5.50 5.75 1.3 5.75 6.00 0.0
Average: 4.10Average: 4.10 Std: Std: 0.680.68
Clarity Factor (CClarity Factor (C8080))
Color Range Beg. Range End Percent -11.00 -10.00 1.5 -10.00 -9.00 3.1 -9.00 -8.00 4.7 -8.00 -7.00 5.6 -7.00 -6.00 13.1 -6.00 -5.00 13.6 -5.00 -4.00 14.7 -4.00 -3.00 19.1 -3.00 -2.00 9.9 -2.00 -1.00 5.1 -1.00 0.00 4.0 0.00 1.00 2.8 1.00 2.00 1.8 2.00 3.00 0.8 3.00 4.00 0.2 4.00 5.00 0.0
Average: Average: -- 4.52 4.52 Std: 2.92Std: 2.92
Dietsch Echo Criterion for MusicDietsch Echo Criterion for Music
Color Range Beg. Range End Percent 0.00 0.13 0.0 0.13 0.25 0.0 0.25 0.38 0.0 0.38 0.50 0.0 0.50 0.63 0.6 0.63 0.75 12.5 0.75 0.88 20.7 0.88 1.00 16.7 1.00 1.13 17.3 1.13 1.25 12.9 1.25 1.38 12.4 1.38 1.50 3.0 1.50 1.63 1.9 1.63 1.75 1.5 1.75 1.88 0.4 1.88 2.00 0.0
Average: 1.00Average: 1.00 Std: Std: 0.290.29
Lateral FractionLateral Fraction
Color Range Beg. Range End Percent 0.00 0.03 0.1 0.03 0.06 3.7 0.06 0.09 10.3 0.09 0.12 13.3 0.12 0.15 16.1 0.15 0.18 14.1 0.18 0.21 9.2 0.21 0.24 9.0 0.24 0.27 9.3 0.27 0.30 7.7 0.30 0.33 4.8 0.33 0.36 2.0 0.36 0.39 0.4 0.39 0.42 0.0 0.42 0.45 0.0 0.45 0.48 0.0
Average: 0.17Average: 0.17 Std: Std: 0.090.09
Binaural Quality IndexBinaural Quality Index
Color Range Beg. Range End Percent 0.00 0.06 0.0 0.06 0.12 0.0 0.12 0.18 0.1 0.18 0.24 0.5 0.24 0.30 2.1 0.30 0.36 6.2 0.36 0.42 7.8 0.42 0.48 7.8 0.48 0.54 8.6 0.54 0.60 12.2 0.60 0.66 13.1 0.66 0.72 18.9 0.72 0.78 15.1 0.78 0.84 6.2 0.84 0.90 1.5 0.90 1.00 0.0
Average: 0.59Average: 0.59 Std: Std: 0.180.18
StatisticsStatistics
ParameterParameter AverageAverage Standard DeviationStandard Deviation
EDTEDT 4.104.10 0.680.68
C80C80 -4.52-4.52 2.922.92
Dietsch MusicDietsch Music 1.001.00 0.290.29
LFLF 0.170.17 0.090.09
BQIBQI 0.590.59 0.180.18
ConclusionsConclusions
Hall geometry affects parametersHall geometry affects parameters Values show focusing effectsValues show focusing effects
EDT, CEDT, C80 80 more uniform over main floor more uniform over main floor
than in the balconythan in the balcony Higher LF in the very center of the roomHigher LF in the very center of the room
Further WorkFurther Work
ProcessingProcessing More detailed statisticsMore detailed statistics Computer Modeling (CATT, EASE)Computer Modeling (CATT, EASE)
Current acousticsCurrent acoustics Historical acousticsHistorical acoustics
No BalconyNo Balcony No Choir LoftNo Choir Loft Smaller Organ CaseSmaller Organ Case Pine TreesPine Trees
AcknowledgementsAcknowledgements
Timothy W. LeishmanTimothy W. Leishman BYU Acoustics Research GroupBYU Acoustics Research Group
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