First Sound Reproduction System in the World Developed Using a Scale Model for the Design of Concert Halls

Realizing high-precision acoustics design with two steps of analysis using computer simulation and a scale model

March 2, 2011Takenaka Corporation

Takenaka Corporation (President: Toichi Takenaka) has been successful in the development of the new “STRADIA® Plus” system for the acoustics design of concert halls and theaters. This new system uses a scale model for acoustics analysis, which reproduces the propagation features of the acoustics in a finished hall and makes these sounds audible(). This is the first time in the world for this type of system to be used.

In addition to making the interior acoustic field audible through “STRADIA®,” the computer simulation system that has been used in the design of many halls, test results based on the sounds that are made audible from the scale model mean there are two steps of analysis, realizing a higher level of precision in the acoustics design.

Takenaka plans to use this new system for the design of new concert halls and in the renewal work of existing halls in the future.

Making sounds audible is the technology used in acoustics design for the prediction, synthesis and reproduction of the sounds of a completed hall from the design data of the building before completion.

Outline of the “STRADIA® Plus” system

The new system synthesizes the music performed and the voices of actors in a completed hall by using a newly-developed ultrasonic wave oscillator and digital signal processing technology. This means that a more real forecast and reproduction of the sounds of the space after completion can be realized.

When carrying out the acoustics design of actual concert halls, Takenaka uses computer simulation in the basic design stage to calculate the acoustic effects of the hall, and synthesizes the actual sounds using the “STRADIA®” Room Acoustics Simulator. The shape and details of the hall are then considered while listening to these sounds.

After that, in the construction design stage, a scale model of the hall (1/10th to 1/20th) is produced, ultrasonic waves are transmitted inside the model; the propagation features up to the listening position are checked; the sounds are made audible (“STRADIA® Plus”), and the basic design is double-checked; and further consideration is given to fine details. Using this method, various complicated and subtle acoustic phenomena, which are difficult to check with computer simulation, can be considered, and the results reflected in the construction design. Up to now there has not been an ultrasonic wave oscillator with sufficient performance, and there has not been a suitable method to convert the sounds inside a model to audible sounds, so even if a model test was carried out, it was not possible to hear the differences in detail.

Features of the “STRADIA® Plus” system

  • In addition to using the “STRADIA®” in the basic design, being able to analyze more real sounds in the construction design means the realization of high-precision acoustic space design.
  • It is possible to reproduce a wide dynamic range of sounds in all frequency bands, even for a grand piano, which has a wide range, or with an instrument with a complicated directionality.
  • Sounds can be reproduced using several different methods, at any place. For example, the sounds can be listened to by 10 people at the same time, so it is easy to get a consensus of opinion from the clients.
  • It is possible to reproduce the differences in seats, or delicate changes in the shapes of the interior.
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Flow chart showing how the sounds are made audible