Steve Ellison

Designing an auditory lab including active acoustics

LIVELab, a new facility at McMaster University, has been developed in order to help support research in areas such as developing intelligent hearing aids, measuring the physiological impact of media presentations, understanding interactions between musicians, and determining effective sounds for medical and warning systems. This room combines a quiet performance space featuring a low nominal reverberation time with technology including active acoustics, multichannel playback, and integral measurement and instrumentation to create a sonically flexible facility for auditory research. The design of the room and its acoustic variability for supporting these research endeavors will be discussed.

Optimizing acoustics for spoken word using active acoustics

Teleconferencing, classrooms, lectures, drama, and worship all rely on spoken word to convey a message. The successful receipt of the message is largely dependent on the acoustic of the room, the vessel for the message, both in amplified and unamplified situations. A room that supports teleconferencing well will have minimal early reflections and reverberation, yet the same room may be used in a classroom environment that would benefit from early reflections. Active acoustic systems can be used to provide this acoustic energy. Early Reflection Benefit (ERB) will be revisited, and active acoustic systems utilized for speech in various contexts will be described.

Prediction and measurement of reverberation increase from electroacoustic architecture systems.

Electroacoustic architecture (EA) systems increase the reverberation time (RT) of rooms by regenerating the physical reverberation of the room, and/or adding electronic reverberation to the direct sound. In regenerative systems, the amount of regeneration is controlled by the loop gain of the system. Increasing loop gain is analogous to reducing the effective absorption in the room. The RT of the electronic reverberator is analogous to the decay time of a physically coupled room, and, therefore, analogous to adding cubic volume to the room. As the electronic RT is increased, there is a point above which the resulting reverberation will begin to be double sloped. This point depends on the gain. The higher the gain, the higher the electronic RT before the resulting reverberation double slopes. In previous work, the gain before feedback of EA systems has been predicted in a statistical approach based on the bulk properties of the room such as RT and cubic volume. This, in turn, can be used to predict the max...

Rich data trove gathered as a result of a unique opportunity with a capacity audience

When an opportunity arises to perform an occupied room measurement, normally a short time is allotted to acquire data in order to minimize event disruption and audience discomfort. We therefore consider ourselves fortunate if one or two data sets are obtained under those conditions. An extremely rare—perhaps unique—opportunity arose from a confluence of factors: a 1600-seat concert hall at Liberty University, with a purposely over-sized area of movable curtains and banners to adjust the architectural reverberation; an installed active acoustics system, Constellation by Meyer Sound; a concert comprising distinct performances by orchestra, choir, and amplified worship band, with intermission to reset the architectural acoustics; and an interested client. The Constellation system provides 48 microphones distributed throughout the space, so a single set of sweeps through a system loudspeaker results in 48 measurements. The variables tested were (a) adjustable acoustic absorption in and out; (b) full audience ...

Active Acoustics at the Appel Room, Jazz at Lincoln Center

The Appel Room (formerly Allen Room) is a 483-seat venue used primarily for jazz performances in the Jazz at Lincoln Center complex in New York City. In 2013 the Constellation active acoustic system by Meyer Sound was incorporated into the room’s architecture. The system allows a wide range of acoustic conditions to be set for any performance. In the first four years of operation, a variety of solo and ensemble jazz artists have performed in this venue. This paper will describe the room, the system, and the results over the first four years of operation with a variety of musicians.

Active acoustics in multi-purpose venues: A ten year retrospective

Multi-purpose venues better serve diverse programs by tailoring their acoustics for each use condition. Active acoustic systems use electronics to provide wide-ranging acoustic adjustability with the press of a button. Over the past decade, the Constellation acoustic system by Meyer Sound has been deployed in over one hundred venues, supporting the performing arts, worship, education, and corporate sectors. This paper presents a survey of such venues and discusses lessons learned.

Observations from the field: Active acoustic systems, architecture, performers, and audience

Active acoustic systems provide the potential for acoustic adjustability with far greater parametric control than with architectural systems. Settings and adjustments may be made and compared in extremely short time frames. With almost limitless combinations possible, how do we quantify and qualify these settings? Observations made during the course of tuning multiple Meyer Sound Constellation acoustic system installations are presented. The importance of adjusting spatial energy balance and early reflections and reverberation parameters, subjective observations and objective measurements, performer and audience impressions, and user interface will be discussed.

Stages with high ceilings, pipe organs, and active acoustics

Two case studies are presented of rooms that have a high ceiling over the stage to accommodate a pipe organ. Svetlanov hall is the principal venue of Moscows International Performing Arts Center. It has two to four rows of chorus seating on two levels at stage left and right. The upstage wall is occupied by the largest pipe organ in Russia. It has a physical reverberation time of 1.7 s, which is within the accepted range for symphonic music, but longer reverberation times would be preferred for some pipe organ repertoire. Christopher Cohan Performing Arts Center at California Polytechnic State University has a proscenium and thrust stage. The Forbes Pipe Organ is housed on the stage right wall of the thrust stage. The symphony usually performs on the thrust stage entirely in front of the proscenium with the solid decorative fire curtain down. Both rooms had poor communication on stage between performers, which led them to implement a solution using active acoustics. In both rooms all of the active acoustic elements overhead of the stage are on motors and can be retracted when not in use. Two case studies are presented of rooms that have a high ceiling over the stage to accommodate a pipe organ. Svetlanov hall is the principal venue of Moscows International Performing Arts Center. It has two to four rows of chorus seating on two levels at stage left and right. The upstage wall is occupied by the largest pipe organ in Russia. It has a physical reverberation time of 1.7 s, which is within the accepted range for symphonic music, but longer reverberation times would be preferred for some pipe organ repertoire. Christopher Cohan Performing Arts Center at California Polytechnic State University has a proscenium and thrust stage. The Forbes Pipe Organ is housed on the stage right wall of the thrust stage. The symphony usually performs on the thrust stage entirely in front of the proscenium with the solid decorative fire curtain down. Both rooms had poor communication on stage between performers, which led them to implement a solution using active acoustics. In both rooms all of the active acoust...

Indoor outdoor acoustics: Active acoustics at the New World Center, Miami Beach Soundscape

The Frank Gehry designed New World Center is home to the New World Symphony in Miami Beach, FL. This facility includes an intimate 756 seat concert hall and is used as a training platform both for symphonic conductors and musicians. The adjacent park uses an active acoustics system to allow a similar number of people in the park to simultaneously experience the indoor concert experience in an open air environment. The immersive sound of the reproduced concert experience is accompanied by a 7000-square-foot projection wall that carries live video of the performance. The system captures the natural acoustic of the concert hall using microphones distributed throughout, and these signals are processed and then transmitted to the park utilizing a set of 160 distributed loudspeakers. The successful design, commissioning, and tuning of the system relied on a team approach between the architect, consultants, manufacturer, installer, and venue operators. Scope within the team is explored, challenges revealed, and ...

Case study: Active acoustics at the Barbara Streisand scoring stage

Scoring stages are recording studios large enough to accommodate an orchestra, and typically used to record music sound tracks for films. The acoustic properties and goals of scoring stages are reviewed, and compared with other venue types. Recently, an active acoustics system was installed in the Barbara Streisand scoring stage on the Sony lot in Culver City, California. The system was used to electronically vary the reflected sound and reverberation during the recording of several film scores. The objectives, design, and performance of the system in the room is reviewed. The range of settings and controls provided to the scoring mixer are described as well as the process used to select parameters for different aspects of the score. These had implications on the artist performance as well as the recording and mixing process. The resultant reverberation times achieved are compared with archetypical orchestral performance venues as well as other scoring stages.