Engineering Sound
CSUF - Meng Concert Hall
Mark E. Rothermel
Principal
Rothermel & Associates, LLC
Architectural Acoustics Collaborative
Engineering Sound = Architectural Acoustics
• Building Acoustic Design to Support
the Programmed Uses of the Hall
• Orchestral Music
• Romantic, Classical & Contemporary
Chamber Music
• Civic Light Opera
• Big Band
• High School Bands
• Opera
• Choral Music
Architectural Acoustics
• HVAC Noise Control
•Quiet Mechanical, Electrical & Plumbing
Systems
• Sound Isolation
•Walls, Roof, Doors & Windows
• Room Acoustics
•Shaping, Materials, Finishes, Moveable
Elements
HVAC Noise Control - Criteria
HVAC Noise Control
• Low Noise Levels Achieved Through:
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Quiet Equipment Selections
Location of Equipment in Relation to Hall
Duct Routing, Dimensions and Lengths
Slow Airflow Velocities
Smooth Takeoffs and Transitions
Location of Remote Volume Dampers
Silencers and Duct Liner
Diffuser/Grille Selections and Sizes
Vibration Isolation of Mechanical, Electrical and
Plumbing Equipment and Piping
HVAC Noise Control
HVAC Noise Control
• Pressurized Main Duct
• Low Velocity Air Drops from
supply air ‘mushrooms’
Sound Isolation
• Plan for Sound Isolation
• Circulation, Lobby, etc. provide buffer
zones
Sound Isolation
• Walls
• Grout-Filled Concrete Block Walls
• Doors
• Sound Rated Acoustical Door Assemblies
• Gaskets on Standard Doors at Vestibules
• Windows
• Thick, Multiple Glazing Layers in Airtight
Frames
• Roof
• Concrete on Metal Deck
Sound Isolation
• Floors
• Isolated, Floated Concrete Floor Slab Over
Structural Slab
• Grad Slab with Perimeter Isolation Joints
• Special Construction
• Box-in-Box Construction
• Perimeter Isolation Joints
• Floated Concrete Slabs
• Vibration Isolated Gypsum Board Ceilings
Room Acoustics - Basics
• Room Volume
• Maximized for Reverberation – 400,000 Cubic Feet
• Shaping
• All Surfaces Have Specific Angular Orientation,
Shape, Radii – Nothing is Arbitrary
• Finishes & Materials
• Heavy, rigid, stiff surfaces for bass support
• Variability
• Movable Drapes & Banners
• Movable Canopy
Room Acoustics - Reverberation
• Retractable Banners and Draperies Vary the Reverberation Time
Room Acoustics - Shaping
Room Acoustics - Shaping
Room Acoustics - Shaping
• Balcony Fascia Shaping
• Shaped & Articulated, Tight Radius Curves
• Highly Sound Diffusive
• Counters Focusing of Horseshoe-Shaped Plan
Room Acoustics - Shaping
• Doubly-Curved, Moveable Canopy
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Ensemble
Attack
Articulation
Clarity
Room Acoustics – Finishes & Materials
• Grout-Filled Concrete
Block Walls
• Concrete on Metal Deck
Roof
• Rigid Interior Shapes and
Surfaces of Heavy Plaster
• No Diaphragmatic
movement
• All to Support Bass
Response
Room Acoustics - Variability
Acoustic Canopy
• Directs Sound Toward Audience
• Facilitates Ensemble by Allowing Musicians to Hear One Another
• Changes the Direct-to-Reverberant Ratio
Room Acoustics - Variability
• Moveable Fabric Banners Change the
Reverberation Time (RT60)
Conclusion
• Quiet
• Allows High Dynamic Range of Music
• Isolated
• No Distractions To or From Neighbors
• Sound
• Carefully Defined Interiors
Questions?