vw = fλ |
d = rt |
sound level |
dB to power
take the difference in the decibels, divide that difference by 10, relationship between the original sound levels equals 10x power |
intensity of sound (watts/m2) |
|
comparison of two intensity values |
|
sound level intensity (dB) |
threshold of human hearing (Io = 1 x 10-12 watts/m2)
|
beats |
beat frequency = |f2 - f1| beat pitch = ½(f1 + f2) |
speed of sound in dry air |
vw = 331 + 0.6T |
open-closed pipe |
for the fundamental, A-N Lpipe = ½ loop = ¼λ |
open-open pipe |
for the fundamental, A-N-A Lpipe = 1 loop = ½λ |
EPD = |L1 - L2| |
constructive: mλ m ∈ {0, 1, 2, 3, ....} destructive: ½(2m - 1)λ m ∈ {1, 2, 3, ....} |
listener moving |
Δf / f = v / vw approaching: f' = f + Δf receding: f' = f - Δf |
source moving |
Δλ/λ = v / vw approaching: λ' = λ - Δλ receding: λ' = λ + Δλ |