04 A Performance Space U of I Borah Theater Michael Joseph Scott Shores + Site Location 01Location Moscow, Idaho 02University of Idaho Located on the University of Idaho Campus in the southwest quarter of Moscow, Idaho. 03Student Union Building Located towards the eastern edge of campus between the bookstore and Greek Road 01 02 03
Room Description Located in the University of Idaho Student Union Building on the second floor. The Borah Theater is a shoebox style design with its rectangular floor plan. Designed for a sound monarchy where sound comes from a single area, the stage. The theater consists of 195 seats and is used for lectures and film. Acoustic Analysis: Absorptive Materials 01 Acoustic Ceiling Tiles Acoustic tiles fill the center soffits above the audience seating to prevent sound from bouncing in the space. 02Acoustic Wall Tiles A quarter of the wall space is taken up by the same acoustic tiles that are located on the theater s ceiling. 03Upholstered Seating The theater houses 195 upholstered chairs for the audience. 04Carpeting Carpet on concrete is the floor finish used in the space.
Acoustic Analysis: Reflective Materials 01Columns and Beams Exposed structure lines the walls and ceiling of the space. The structure is made up of concrete. 02HVAC System The HVAC vents are located along the side walls of the theater and protrude slightly into the space from the structure. 03Walls Three quarters of the wall surface is reflective concrete. It is primarily the side walls that are concrete while the back wall is a sheetrock partition. Acoustic Analysis: Physical Model A physical model of the space was constructed out of chipboard and foil to represent absorbent and reflective surfaces. A laser pointer was then used to determine how sound would travel through the space. 02 Walls Because of the reflective material on the walls, sound is able to reflect diffusely and evenly disperse itself into the middle of the space. Only issues is the columns bouncing noise back towards the stage. 03 Ceiling The concrete structure, most notably the beam nearest to the stage, reflects sound back to the stage and the sound s source as seen below. 02 03
Acoustic Analysis: Absorption Surface Material Area (ft2) Absorption Coefficient Absorption (Sabins) Floor Carpet 1500.14 210 Walls Concrete 1180.31 366 Sheetrock 350.05 17 Acoustic Tile 532.83 442 Ceiling Acoustic Tile 1080.83 896 Seating Occupied Seating 840.88 739 2670 Acoustic Analysis: Absorption The acoustics in the Borah Theater are leaning more towards an excessively dead room with 2670 sabins in a volume of 30050 cubic feet. Due to the activities that take place in the space the acoustics should lean more towards being more live.
Acoustic Analysis: Revergeration Overall, the room is too absorptive for the appropriate amount of sound to reach the audience. As a result some of the absorptive materials should be taken out and be replaced with more reflective materials in order for the acoustics to perform better for the space s intended activities. Tr=.049(volume)/ absorbency Tr=.049(30050)/ 2670 Tr=.55 Reverberation Time Ideal Reverberation Times Acoustic Redesign: Materials + Methods 01 Acoustic Reflector Panels Acoustic reflector panels placed in the two soffits closest to the stage will help bounce sound down towards the audience and stop sound from bouncing back to the stage from the exposed beams. Remove Ceiling 02Absorptive Panels Removal of the remaining ceiling panels on the ceiling will allow for a greater reverberation in the space, along with sending sound downwards towards the audience. Remove Wall 03Absorptive Panels Removal of the absorptive panels on the side walls will allow for greater reverberation time.
Acoustic Redesign: Physical Model 01 Walls The removal of absorptive panels on the wall and the addition of reflective material helps liven up the acoustical qualities of the space. 02 Ceiling The ceiling acoustic reflector panels block sound to hitting the exposed concrete beams and instead bounces sound towards the audience and the back wall. 01 02 Acoustic Redesign: Physical Model Comparison Before Before After After
Acoustic Redesign: Absorption Surface Material Area (ft2) Absorption Coefficient Absorption (Sabins) Floor Carpet 1500.14 210 Walls Concrete 1180.31 366 Sheetrock 882.05 44.1 Ceiling Sheetrock 360.05 18 Ceiling Panels 720.1 72 Seating Occupied Seating 840.88 739 1449.1 Acoustic Analysis: Revergeration With the removal of some absorptive materials and addition of reflective materials generated a new reverberation time of 1.01, ideal for the activities that occur in the space. Tr=.049(volume)/ absorbency Tr=.049(30050)/ 1449.1 Tr= 1.01 Reverberation Time Ideal Reverberation Times
Conclusion Overall, the Borah Theater needed some work to acoustically appropriate for lectures and film. By integrating acoustic reflector ceiling panels, along with replacing the acoustic panels from the ceiling and walls with sheetrock, we were able to lower the amount of absorption in order to create a longer reverberation time. The Borah Theater absorbency was reduced from 2670 sabins to 1449.1 sabins, making the reverberation time go from.55 to 1.01 to make the reverberation ideal for the space s functions. That s pretty neat.