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Jese Reyes
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Homework Statement
Spaker located at 90 feet from a auditorium chair. The sound pressure level at the chair is 70 dB. The first reflection from the roof takes 200ms to get to the chair.
What distance does the first reflection travel to get to the chair if the room temperature is 303.15 K?
What is the SPL of the first reflection assuming a perfect reflection from the roof?
What would the delay be of the first reflection after the direct sound has reached the chair first?
Homework Equations
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Reflection delay = (reflected path - direct path)/ speed of sound
Reflection Level at listening position = 20 log (Direct sound/Reflection distance)
The Attempt at a Solution
90ft = 27.432 mts
331 + .6(30C) = 349 ms This is the speed of sound at 303.15K
Solve for Rflection path 200ms= (rpath - 27.432 mts)/349 ms rpath=69800 mts does this make sense?
SPL = 20 log (27.432/6980) = -68.11 dB
Im not sure my math is making sense. I am having trouble understanding how to integrate these type of problems when calculating delays, reflection distance and SPL.
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