Active Acoustics in Concert Halls – A New Approach

Active acoustics offers potential benefits in music halls having acoustical shortcomings
and is a relatively inexpensive alternative to physical modifications of the
enclosures. One critical benefit of active architecture is the controlled variability of
acoustics. Although many improvements have been made over the last 60 years in
the quality and usability of active acoustics, some problems still persist and the
acceptance of this technology is advancing cautiously. McGill’s Virtual Acoustic
Technology (VAT) offers new solutions in the key areas of performance by focusing
on the electroacoustic coupling between the existing room acoustics and the simulation
acoustics. All control parameters of the active acoustics are implemented in
the Space Builder engine by employing multichannel parallel mixing, routing, and
processing. The virtual acoustic response is created using low-latency convolution
and a three-way temporal segmentation of the measured impulse responses. This
method facilitates a sooner release of the virtual room response and its radiation
into the surrounding space. Field tests are currently underway at McGill University
involving performing musicians and the audience in order to fully assess and
quantify the benefits of this new approach in active acoustics.