Document Type

Restricted Campus Only

Publication Date

Spring 2021


Dr. Joseph Kneer of the Trinity University Symphony Orchestra seeks to improve the acoustics of the Ruth Taylor Recital Hall on campus. The current dilemma can best be summarized as the louder “hot” zones in the percussion sections drown out the much quieter “dead” zones in the woodwind section. The Sound Dynamics Team was tasked with designing, building and testing a system that improves the acoustic balance of the stage that is visually appealing, easily stored and within budget. The following report covers the features of our complete design and the two subsystems that can be utilized by Dr. Kneer with a large degree of freedom. The initial purpose of each component was to take advantage of the different type of sound treatments available, such as amplification, dampening, and diffusing. This multivariate problem let to many challenges which eventually resulted in a change of focus in the design requirements, and how success was defined. Following the design overview is an evaluation of the final design through the scope of the project requirements and constraints, as well as the associated tests used in assessing the overall system’s performance.

The project design was constrained by Dr. Kneer and the Engineering Department at Trinity. The design could not make any permanent changes to the physical structure of Ruth Taylor Recital Hall, could not be visually disruptive from the audience and needed to comply with all OSHA guidelines relevant to the designs chosen, all while staying within budget. The first constraint was achieved by ensuring each component was not only mobile, but also storable in the designated area backstage. The aesthetics of the hall were maintained by having the designs either minimally visible, as is the case of the acoustic mats, or painted a color pre-approved by Dr. Kneer, in the case of the acoustic walls. All OSHA guidelines were met through careful consideration in the design and fabrication phases of the project. The mats were made to be thick, dense and gripped on the bottom to allow for stability, durability and to eliminate risk of slippage. The acoustic walls were deemed in compliance with OSHA standards following the slipping and tipping tests administered. The budget was maintained through strategic planning, leaving the team almost $500 under budget.

While initially designed to maximize the effects of the intended sound treatment, complexity of the acoustic space and an inability to test with a full orchestra due to the coronavirus pandemic led the group to change its focus to instead provide Dr. Kneer with a system of tools to be used largely at his discretion. The testing for each component was still performed and documented in order to provide a general user’s guide that informs the reader of the real-world effects of the components already built. The criterion for a successful positioning is if there is a change in 3 decibels from the baseline in the appropriate direction. That would mean a –3 dB change for the absorptive mats and a +3 dB change for the acoustic walls. The user guide satisfies the project requirements by mapping out the effects of positioning and angling of the walls with different instruments, noting which combinations led to a successful outcome in the user guide following this report.

Overall, the Sound Dynamics Team created successful prototype to treat the sound imbalances in Ruth Taylor Recital Hall. While the original project requirements had to be adjusted given the sheer complexity of the room acoustics and important COVID regulations, a foundational understanding of how the components interact with the space will allow Dr. Kneer to maximize the effectiveness of the components in a way that works best for his art and his students.


Team Advisor: Dr. Darin George

ENGR 4382

Ruth Taylor, component user manual.pdf (160 kB)
Sound Dynamics User Manual