Midterm

Question 1

Resonance

Answer 1

The tendency of a system to vibrate at a greater amplitude with some frequencies than others

Question 2

Newton’s Second law of Physics Equation

Answer 2

F = ma

Force = Mass x Acceleration

Question 3

Pressure Equation

Answer 3

P = F/S

Pressure = Force/Surface Area

Question 4

Energy Equation

Answer 4

E = Fd

Energy = Force x Distance

Question 5

Power Equation

Answer 5

W = E/t

Watts = Energy/Time

Question 6

Intensity Equation

Answer 6

I = W/s

Intensity = Watts/Surface Area

Question 7

Speed of Sound Equation

Answer 7

Lamda x f = c

Wavelength x Frequency = The Speed of Sound

Question 8

Frequency Equation

Answer 8

f = 1/T

Frequency = 1/Period

Question 9

Loudness Equation

Answer 9

Li = 10Log (I/Iref)

Loudness = 10Log x (Intensity of the Sound/Intensity of a reference Sound)

Question 10

Reference Intensity Equation

Answer 10

Iref = 10^-12(W/m^2)

Referernce Intensity = 10^-12(Watts/meters^2)

Question 11

Loudness in Watts Equation

Answer 11

Lw = 10log(W/Wref)

Loudnesss in Watts = 10log(Watts/Watts Reference

Question 12

Reference Watts Equation

Answer 12

Wref = (10^-12)W

(Reference Watts = (10^-12)W

Question 13

Loudness Pressure Equation

Answer 13

Lp = 10log(P/Pref)^2 = 20log(P/Pref)

Loudness Pressure = 10log(Pressure/Reference Pressure)^2 = 20log(Pressure/Reference Pressure)

Question 14

Pressure Reference Equation

Answer 14

Pref = 2 * 10^-5(N/m^2)

Reference Pressure = 2 * 10^-5(Newtons/m^2

Question 15

Change in Loudness Pressure Equation

Answer 15

DeltaLp = 20log(r1/r2)

Change in Loudness Pressure = 20log(Reference 1/Reference 2)

Question 16

Speed of Sound on a String

Answer 16

c = SqRoot(T/p)

Speed of Sound = SqRoot(Tension/Mass Density)

Question 17

Fundamental Frequency for Open/Open or Closed/Closed Pipe

Answer 17

F0 = c/2L

Question 18

2nd Harmonic for Open/Open or Closed/Closed Pipe

Answer 18

F1 = 2c/2L

Question 19

3rd Harmonic for Open/Open or Closed/Closed Pipe

Answer 19

F2 = 3c/2L

Question 20

Fundamental Frequency for an Open/Closed Pipe

Answer 20

F0 = c/4L

Question 21

2nd Harmonic for an Open/Closed Pipe

Answer 21

F1 = 3c/4L

Question 22

3rd Harmonic for an Open/Closed Pipe

Answer 22

F2 = 5c/4L

Question 23

Frequency of Room Modes Equation

Answer 23

Fn = c/2 x SqRoot( (nx/lx)^2 + (ny/ly)^2 + (nz/lz)^2 )

Frequency of the room mode = speed of sound/2 x SqRoot( (Mode 1/length)^2 + (Mode 2/width)^2 + (Mode 3/Height)^2 )

Question 24

Equivalent Room Absorption Equation

Answer 24

A = E(Alphai x Si)

Room Absorption = The summation of (All absorption coefficients x All Reverb Times)

Question 25

Sabine’s Formula

Answer 25

T60 ≈ V/(6A)

60 seconds of time ≈ Room Volume/(6 x Room surface absorption)