The Design of our Concert Hall
Using Google Sketchup™
We are free to use any design methodology, however the following aspects should be considered in our design.
Volume. Deciding the volume and dimensions of the room is a natural starting point of our design. Start our iteration by assuming that a ceiling height of approximately 17 meters will be necessary to reach a suitable reverberation time. The required volume will to a large extent depend on our choice of audience
seating; Properties such as seat density, seat materials, isles, etc., are important to consider.
Reverberation time. Try to find values for suitable RTs for the type of room and volume. Determine the absorption required to obtain these RT, using e.g. statistical room acoustics.
Shape. It is an important but tricky task to select a shape that gives good early reflections (see early reflections below) and an even distribution of the sound pressure over the audience area (see seating below). The shoebox, fan, and inverted fan shapes are popular. A more complex shape naturally leads to a
more complex modeling process but may solve some problems with early reflections and audience area coverage.
Seating. Providing good line of sights for as much of the audience as possible is important both for visual and auditory impressions, hence seating layout is something which should be considered early on in the design process. Seating layout is naturally tightly connected to shape and to reverberation time.
Early reflections. Early reflections are often considered as contributing to characteristics such as clarity, intimacy and source width and hence important in concert hall designs. Early reflections could be delivered via reflectors or by the walls and ceiling. By using the image source method you could decide on how to
place reflectors to obtain “good” early reflections. Consider both the ITG (initial time gap) and the spatial distribution of the early reflections.
Diffusion. It is often desirable that the late, reverberant field is randomly distributed in space to create the sensation of being enveloped by the reverberant sound field. Hence, scattering panels and objects are often incorporated into concert halls to obtain such random distribution of the reverberation. Diffusion can also be obtained by the room’s shape and random distribution of absorption.
Step 1: the shape and the characteristics of the hall
Step 2: the seating
View from Sketchup