Engineering SoundCSUF - Meng Concert Hall

Mark E. RothermelPrincipal

Rothermel & Associates, LLCArchitectural Acoustics Collaborative

• 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

Engineering Sound = Architectural Acoustics

• HVAC Noise Control•Quiet Mechanical, Electrical & Plumbing Systems

• Sound Isolation•Walls, Roof, Doors & Windows

• Room Acoustics•Shaping, Materials, Finishes, Moveable Elements

Architectural Acoustics

HVAC Noise Control - Criteria

• Low Noise Levels Achieved Through:• 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

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

•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

Sound Isolation

• 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 - Basics

• Retractable Banners and Draperies Vary the Reverberation Time

Room Acoustics - Reverberation

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• Ensemble• Attack • Articulation• Clarity

• 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 – Finishes & Materials

Acoustic Canopy • Directs Sound Toward Audience• Facilitates Ensemble by Allowing Musicians to Hear One

Another• Changes the Direct-to-Reverberant Ratio

Room Acoustics - Variability

Room Acoustics - Variability

• Moveable Fabric Banners Change the Reverberation Time (RT60)

•Quiet• Allows High Dynamic Range of

Music

• Isolated• No Distractions To or From

Neighbors

•Sound• Carefully Defined Interiors

Conclusion

Questions?