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Engineering Acoustics Homework 7
1. Calculate the frequencies for the ten lowest normal modes of a rigid-walled room of dimensions 2.59m
x 2.42m x 2.82m. Present these frequencies in order from smallest to largest and box your results.
Use the stem comman
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2.1
2.1.2
HARMONIC FUNCTIONS
67
Complex Variable Representation
The process of converting phase angles between sine and cosine functions is the first
of many tasks that require the use of t
FlyInspiredMicrophones
NealA.Hall
November20,2014
TheUniversityofTexasatAustin
ElectricalandComputerEngineeringDepartment
ForOfficialUseOnlyNotforPublicRelease
TheOrmiaOchracea
A special fly native to South Texas
and FL.
Why special ?
Locates crickets usi
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1. Your roommate has proposed hanging a curtain in your
apartment to act as a sound barrier for added privacy. She
recommends this ikea curtain. Use the normal incidence mass
low to compute the transmission coefficient for this idea.
How much transmission
Homework 3
More Practice with Representing Sinusoids as Complex Exponentials
1. See Ginsberg handout uploaded to the course BB website. Work exercise 2.8.
2. See Cogdell handout uploaded to the course BB website. Work exercises 4.12.
3. Work exercise 4.13
Engineering Acoustics, Homework 8
Spherical Waves
1) As shown in lecture, the 3D wave equation in spherical coordinates, assuming spherical symmetry,
reduces to
.
equation (2.1)
Prove that the equation above may be written as
.
equation (2.2)
Prove this b
Engineering Acoustics Homework 9
Two point sources, separated by distance d radiate with the same amplitude, frequency, and phase. Note
that for the case derived in class, the two point sources had the opposite phase. Use the geometry and
procedure employ
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Engineering Acoustics Homework 6
Consider the wall of a building that measures 10 ft x 20 ft and is made of 4 inch brick (with 1/2 inch
plaster on both sides). This wall has a glass door in it, which measures 3 ft x 8 ft. The surface densities are
210 and
Engineering Acoustics, Homework 5
Reflection / Transmission and the Mass Law
1) An agent from the Central Intelligence Agency (CIA) has contacted you regarding an important
intelligence gathering problem. She is wondering if the commercially available PDV
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Engineering Acoustics, Homework 1
1. Complex Numbers and Oscillations: Consider the waveforms
= 3 cos100 + 20 , = 1.3 100 15 , and = +
(i) Use trig identities to write a single cosine expression for the waveform
(ii) Write in the complex form
(iii)
Engineering Acoustics, Homework 2
1. Sound Speed: derive the speed of sound waves assuming isotropic (constant temperature) rather
than isentropic (constant entropy) compressions. Hint: recall
=
and the fact that the ideal gas equation is always valid
Engineering Acoustics
Fall 2014
EE 363N (17190), ME 379N (18985)
TuTh 9.30am-11am, ETC 2.114
N. A. Hall (nahall@mail.utexas.edu)
TEXT: Acoustics: Sound Fields and Transducers by Leo L. Beranek (Author), Tim Mellow
(Author)
GRADING: 30% HW, 35% midterm, 35
HW 10 and HW 11
HW 10, Due Tuesday, Nov. 25th
This problem has to do with a moving coil loudspeaker mounted in a bass reflex (vented box)
enclosure. The driver and the enclosure have the parameters given in the attached spec pdf. Obtain a
circuit model of