{"id":62882,"date":"2022-04-13T16:18:37","date_gmt":"2022-04-13T20:18:37","guid":{"rendered":"https:\/\/www.hajim.rochester.edu\/senior-design-day\/?p=62882"},"modified":"2022-09-12T09:51:24","modified_gmt":"2022-09-12T13:51:24","slug":"gavett-studio-acoustic-treatment","status":"publish","type":"post","link":"https:\/\/www.hajim.rochester.edu\/senior-design-day\/gavett-studio-acoustic-treatment\/","title":{"rendered":"Gavett Studio Acoustic Treatment"},"content":{"rendered":"\n
Team – William Bellows, Joe Bumpus, Alex Mancuso, Nicholas Muscarella<\/h5>\n\n\n\n
Mentors – Mike Heilemann, Sarah Smith, and Dan Phinney<\/h5>\n\n\n\n

Abstract<\/h2>\n\n\n\n

The Gavett Hall Recording Studio is well known amongst AME students for its beautiful design, incredible resources, and signature reverb. Although this reverb is loved and embraced by many, some students wish for the ability to limit this sound for more control in post production. The aim of this project was to create a modular solution for this issue, capable of treating the sound with the option of leaving it intact. The studio’s current acoustic properties\u2014impulse and frequency magnitude responses, respectively\u2014were first measured to identify the current acoustic profile of the room. With these results in mind, the final design is a mobile acoustic panel tailored towards minimizing reflections from the ceiling and walls, absorbing the most reverberant frequencies shown in our data. Simulated results of multiple acoustic panels in the studio show a promising decrease in reverberation time, and make a strong case for further investment from the AME\/ECE Department.<\/p>\n\n\n\n

Pre-Planning and Control Measurements<\/h2>\n\n\n\n

To ensure measurements were not impacted by equipment bias, the system was first measured in the CSB Whisper Room (semi-anechoic chamber). The measurement equipment system included:<\/p>\n\n\n\n

\u25cf MATLAB impulseResponseMeasurer
\u25cf Universal Audio Apollo Solo (interface)
\u25cf Behringer ECM8000 microphone
\u25cf JBL 308P MkII & LSR310S monitor\/subwoofer<\/p>\n\n\n\n

Four measurements\u2014two exponential sine sweeps and two white noise\u2014showed a similar flat response, almost identical from 300Hz-20kHz (important as suspected reverb issue lies in high mid frequencies). These measurements are as seen below:<\/p>\n\n\n\n

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Whisper Room equipment system control measurement<\/figcaption><\/figure><\/div>\n\n\n\n

Gavett Studio live room was then measured from 10-22kHz using s exponential sine sweeps with 5s silence between runs for maximum frequency resolution. Measurements were taken in eight locations around the studio (shown below, with front right middle microphone\/speaker placement as an example) in order to identify differing acoustic properties associated with architectural design.<\/p>\n\n\n\n

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Gavett Studio control measurement setup<\/figcaption><\/figure><\/div>\n<\/div>\n\n\n\n
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Front right middle placement<\/figcaption><\/figure><\/div>\n<\/div>\n<\/div>\n\n\n\n

Control Measurement Results<\/h2>\n\n\n\n

The measured data was processed to determine the room frequency magnitude response and the energy decay curve, allowing for the calculation of RT60 (the time after a sound source ceases that it takes for the sound pressure level (SPL) to reduce by 60dB). The impulse response was processed with a \u2153 octave band filter applied at American National Standards Institute defined center frequencies. For the purpose of this data, RT30 (two times the time for SPL to decrease by 30dB) was used as an estimate to avoid hitting the noise floor. Results showed ordinary reverberation time. There is an expected dense reverb around 1kHz, tapering off drastically at lower frequencies but staying mostly equal or slowly decreasing as frequencies get higher. There is no distinct difference between locations, as can be seen from the two sets of plots below, one from the back left of the room and one from the front right middle, as examples. This consistency suggests reflections from the floor and ceiling. The impulse response from each of these two measurements can be heard below.<\/p>\n\n\n\n

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Back Left impulse response and energy decay curve, \u2153 octave filter applied at 1000Hz. T30 is as seen in the lower left corner<\/figcaption><\/figure><\/div>\n<\/div>\n\n\n\n
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Back Left magnitude response shows high frequency noise with slight comb filtering, corresponding to audible high frequency, shimmery reverb<\/figcaption><\/figure><\/div>\n<\/div>\n<\/div>\n\n\n\n