Acoustic Analysis Case Study

Sound Absorption and Reverberation Analysis Monica Valle Sheryl Wadehra Valentina Sanchez

Environmental Control II Professor Alice Guess 5/20/2019

Crites Hall Theater Acoustic Analysis

This assignment requires the application of class readings and lectures pertaining to sound absorption and reverberation to the analysis of the acoustic properties of real world spaces. The acoustical task enacted for each room was the performance of a song by our groupmate Valentina, while recording analyzing the acoustic performance characteristics of each space and the qualitative aural experience. The rooms chosen were Crites Hall Theatre and Savannah Cultural Arts Center Studio Theatre, as they were of similar sizes, layout, and overall use. Both rooms were measured and modeled in Revit to get an accurate comparison of the scale of each, while the room surface finishes and floor to ceiling and detail measurements were recorded for our study.

The procedure as follows: 1. Choose two similar sites for comparison.

2. Generate documents of your sites.

3. Enact an acoustical task in each room and analyze acoustic performance characteristics.

4. Estimate sound absorption coefficients and noise reduction coefficients for each surface in each room in occupied and unoccupied conditions.

5. Calculate the total absorption and total reverberation type.

6. Find the optimum reverberation time for our room volumes and compare them with previous findings.

7. Draw conclusions based on findings and make suggestions regarding how the performance of one or both of the spaces could be improved.

Crites Hall Theater Documentation of Site: • The chairs are aligned in consecutive straight rows, generally in a direction • There are no tables, desks or additional furniture used in this theater.

• The theater itself is angled down slightly and the rows are offset from each other, so that guests a clear view even if someone taller sits in front of them.

• The main materials used are concrete and carpet • Carpets are extremely effective sound absorbers because the individual fibers, piles tufts and underlay have different resonant frequencies at which they absorb sound.

• There is a gap of 24” between rows providing enough room for guests to get in and get out of their rows to go to the bathroom, leave early, etc Acoustical Task: Musical Performance The clarity of musical signals was very good.

The clarity of speech signals was good.

The amplitude of the musical signals was fair.

The amplitude of speech signals was fair.

The distinction of high range (sharp) frequency signals fair.

The distinction of low range (deep) frequency signals poor.

The distinction of mid-range frequency signals good.

The distinction of vocal sound signals good.

The sound reverberation characteristics of the room fair.

Our overall aura experience of the room was fair.

There was no internal noise during the event.

There was no external noise but there was the background noise of the HVAC system.

The clarity of her voice was evident, but the air conditioning was so loud that it silenced her voice. When she hit high notes, they were clear but low notes weren’t. There was no street noise in the theater.

Qualitative Aural Experience: The overall experience of being at Crites Theater was alright. Since the space is catered to performing arts, we were expecting the quality to be outstanding. The clarity of voice was evident but was shortly overpowered by the air conditioning system. The street noise wasn’t disruptive and couldn’t be heard. The raised ceiling lighting cage and staggered seating now create much better sight lines for the viewers. New chairs, carpet, a wheelchair lift and a black box were all components of the theater.

Crites Hall Theatre - Unoccupied

Crites Hall Theatre - Occupied

Savannah Cultural Arts Center Acoustic Analysis

This assignment requires the application of class readings and lectures pertaining to sound absorption and reverberation to the analysis of the acoustic properties of real world spaces. The acoustical task enacted for each room was the performance of a song by our groupmate Valentina, while recording analyzing the acoustic performance characteristics of each space and the qualitative aural experience. The rooms chosen were Crites Hall Theatre and Savannah Cultural Arts Center Studio Theatre, as they were of similar sizes, layout, and overall use. Both rooms were measured and modeled in Revit to get an accurate comparison of the scale of each, while the room surface finishes and floor to ceiling and detail measurements were recorded for our study.

The procedure as follows: 1. Choose two similar sites for comparison.

2. Generate documents of your sites.

3. Enact an acoustical task in each room and analyze acoustic performance characteristics.

4. Estimate sound absorption coefficients and noise reduction coefficients for each surface in each room in occupied and unoccupied conditions.

5. Calculate the total absorption and total reverberation type.

6. Find the optimum reverberation time for our room volumes and compare them with previous findings.

7. Draw conclusions based on findings and make suggestions regarding how the performance of one or both of the spaces could be improved.

Savannah Cultural Arts Center StudioTheater Documentation of Site: • The studio theater has a dual function of being a conference room and dance theater.

• The chairs and table took up half of the room approximately and were made of wood.

• The space consists of brick, glass and hardwood flooring • There are curtains that hide acoustic panels behind them and a small sound booth for people to control sound in.

Acoustical Task: Musical Performance The clarity of musical signals was good.

The clarity of speech signals was good.

The amplitude of the musical signals was fair.

The amplitude of speech signals was fair. The distinction of high range (sharp) frequency signals fair.

The distinction of low range (deep) frequency signals good.

The distinction of mid-range frequency signals good.

The distinction of vocal sound signals good.

The sound reverberation characteristics of the room fair.

Our overall aura experience of the room was good.

The studio itself was multipurpose with no permanent seating.

The floor was flat and extremely smooth unlike the carpet used in Crites Hall Theater.

It was easier to hear the music performance as there was no disruption from any of the systems.

The lighting used was a diffused downlight which was fitting since dancers primarily occupied that space.

Qualitative Aural Experience: SCAC had more acoustical reinforcement throughout the space. There are acoustic panels, curtains, and wood flooring. Wood isn’t the best for sound absorption since it is considered a solid surface that reflects sound.

We noticed that the brick was a veneer, which soundproofed the space. Since it was insulated heavily, we couldn’t hear noise from the street because it was canceled. The reverberation can be brought down by wood paneling so that the stereo does not have to be turned up to full volume to be understood.

SCAC Studio Theatre - Unoccupied

SCAC Studio Theatre - Unoccupied

Conclusion Crites Hall was roughly twice the size of the SCAC, but the cultural arts center was in a square shape it has less capacity but better-quality sound. Crites Hall had the basic components of a theater but lacked the strategies, meanwhile SCAC had acoustic paneling, multiple windows, and brick veneer. The walls at SCAC are rough and tend to diffuse sound reflecting it in a variety of directions.

This allows the users to perceive sounds from every part of the room, making the room seem lively and full. The smooth walls at Crites failed to give the room a full sound. Crites also had these lamps that looked like shutters which provided ambient lighting throughout the space.

Wanna see the acoustical task? Click the link below! https://vimeo.com/337027611