Last Modified : Thu, 09 Jul 15

- Instructor: Jont Allen (NetID: jontalle); ECE 403 Websites: 2013, 2012, 2011,2010, 2009; 2008; Time-table: UIUC-ECE403; Text:
*Electroacoustics*(Buy, TOC, Preface, Preface1, djvu); - TA: Noori Kim (nkim13@illinois.edu); Office hours: Wednesday 12:00-1:00PM, 260 Everitt Lab; Allen Office hours: 2-3 Friday (after lab)
- Calendars: Class, University; Time, place, etc. official
- Topics: How to analyize a loudspeaker; acoustic wave phenomena; acoustics of rooms and auditoriums; artificial reverberation and sound localization/spatialization; Transducer design (2-port networks, loudspeakers, microphones); Topics in digital audio.
- Goals, Syllabus: 2013; Assignments: See {$Daily Schedule$} below;Software: G7 software
- This week's schedule

L
| W
| D
| Date
| TOPIC |

Part I: 1-port Network Theory (5 Lectures: L1-4,6; 1 Labs: L5) | ||||

1 | 3 | M | 1/14 | *Introduction to what you will learn this semester: You will understand how a loudspeaker works by learning the basic theory along with hands-on lab experiments. *Everyone will work in a small group (ideally 4 students per group). *Theory will be taught on Monday and Wed, while the Labs will be on Friday. *Review of ECE-210: Fourier {$\cal F$} and Laplace {$\cal L$} Transforms; Impedance {$Z(s)$} and other complex functions of complex frequency {$s$}*The Curious Case of {$\log(-1)$},{$j^j$}, {$(-1)^t$} and {$j^t$} |

2 | W | 1/16 | *Applications of the Laplace transform {$h(t) \leftrightarrow H(s)$} where {$t$} is time and {$s=\sigma+j\omega$} is complex-frequency *A detailed comparison of the step function {$u(t)$} for each transform: Why {${\cal F} u(t) =\pi \delta(\omega)+1/j\omega$} and {${\cal L} u(t)=1/s$} are not the same. *Impedance; Analytic functions; *Functions of a complex variable: The calculus of Analytic functions {$dH(s)/ds$}, {$\int_C H(s) ds$}. *Convolution of vectors {$\leftrightarrow$} product of polynomials: {$a \star b \leftrightarrow A(z)\cdot B(z)$}, where {$a \equiv [a_0,a_1,a_2, \cdots]^T$}, {$b \equiv [b_0,b_1, \cdots]^T$} and {$A(z)\equiv(a_0+a_1z+a_2z^2 \cdots)$}, {$B(z)\equiv(b_0+b_1z+ \cdots)$} | |

3 | F | 1/18 | *Solving differential equations: The characteristic polynomial {$H(s)$}*Properties of {$H(s)=N(s)/D(s)$}: Roots of {$D(s)$} in LHP. *Definition of the Inverse Laplace transform {${\cal L}^{-1}$}: {$f(t)u(t) = \int_{\sigma_0-j\infty}^{\sigma_0+j\infty} F(s)e^{st}\frac{ds}{2 \pi j}$}*Homework 1: HWa (due 1/28/2010) | |

0 | 4 | M | 1/21 | MLK Day; no class |

4 | W | 1/23 | *Definition of an impedance as an Analytic function {$Z(s)$}: Must satisfy the Cauchy-Riemann conditions, assuring that {$dZ/ds$} and {$\int_C Z(s) ds$} (e.g. {${\cal L}^{-1}$}) are defined.*By using the Residue Thm, and the Cauchy Integral Theorm, one may compute {${\cal L}^{-1}$} | |

5 | F | 1/25 | First Lab: 251EL (your iCard should get you into the lab) *Set up groups; learn about hardware | |

6 | 5 | M | 1/28 | *Special classes of impedance functions as: Minimum phase (MP), positive real (PR), and transfer functions as: all-pole (Strictly-IIR), all-zero (Strictly-FIR) and allpass (AP) functions *Detailed example using of a 1{$^{st}$}-order lowpass filter via the Laplace Transform {$\equiv \cal L$} In the future, move HWb (Lab Exercise) here, or swap HWc with HWb |

2-port Linear System Theory (4 lectures: L7,9-12, 2 Labs: L8,L11) | ||||

7 | W | 1/30 | *2-Port networks; Definition of T [Pipes (53)] matrix and conversion method between Z and T matrix [Van Valkenburg (65)] (pdf, djvu) | |

8 | F | 2/1 | Second lab (251EL) *Setup of hardware; Learn how to make impedance measurements: Circuit Schematic Δ *Calibration of hardware | |

9 | 6 | M | 2/4 | *Terminology (How do you know if you have learned something? Can you explain a complex concept, given a defining word?) *Hunt's 2-port impedance model of the loudspeaker *Carlin 5+1 network postulates (pdf, djvu) *Homework 2 (Lab exercise) HWb (due: Wed, Feb 13, 2013) |

10 | W | 2/6 | *2-port networks: Transformer, Gyrator and transmission lines *Moving coil Loudspeaker I; 2-port equations with f = Bl i, E = Bl u | |

11 | F | 2/8 | No class due to lab *Measurement of 2-port RC example + demo of stimresp *Homework 3: HWc (due Mon Feb 20, 2013) *Example of LaTeX (Hint: Try doing your HW using LaTeX!) | |

12 | 7 | M | 2/11 | *2-port transducers: motional impedance (Hunt Chap. 2); Read Kim and Allen (2013) pdf *The Maxwell Faraday Law in differential and integral form |

Exam I should appear in Week 12, following Lecture 7 | ||||

Acoustic Transmission Line Theory (5 lectures L13,15-16,18-19; 2 Labs: L14,17; Exam I: L20) | ||||

13 | W | 2/13 | *Uniform Transmission line; reflections at junctions *Forward, backward and reflected traveling waves *Reciprocal and reversible 2-port networks (T and Z forms) | |

14 | F | 2/15 | *No class due to lab *First measurement of a loudspeaker input impedance | |

15 | 8 | M | 2/18 | *Review of Acoustic Basic Acoustics (Pressure and Volume velocity, dB-SPL, etc.) |

16 | W | 2/20 | *Acoustic Intensity, Energy, Power conservation, Parseval's Thm., Bode plots;*Spectral Analysis and random variables: Resistor thermal noise (4kT). HWc Due Today. *Move HWd here in the future | |

17 | F | 2/22 | No class due to lab | |

18 | 9 | M | 2/25 | Review for Exam I, Lectures 1-12 |

19 | W | 2/27 | No class due to: Exam I, 7-9PM Room: EVRT 241, Wed Feb 27, 2013 | |

20 | F | 3/1 | *Lab | |

Part II: Waves and Horns (3 lectures L22,25-26,28; 2 Labs: L23-24; Exam II: L27) | ||||

21 | 10 | M | 3/4 | *Acoustic wave equation. *Acoustic horns: Tube acoustics where the per-unit-length impedance {${\cal Z}(x,s)\equiv s \rho_0/A(x)$} and admittance {${\cal Y}(x,s)\equiv s A(x)/\eta_0 P_0$} depend on space {$x$} (Horns); HWd: Transmission Lines (due Mon, Mar 11, 2013) |

22 | W | 3/6 | *Spherical wave off of a sphere *Radiation (wave) impedance of a sphere *Wave equations and Newton's Principia (July, 1687); d'Alembert solutions in 1 and 3 dimensions of the wave equation | |

23 | FS | 3/8-9 | Regular Lab 251EL; Engineering (Open House, UIUC Calendar) | |

24 | 11 | M | 3/11 | *Radiation impedance of a Horn pdf Δ *Transmission Line discussion *Loudspeakers: lumped parameter models, waves on diaphragm *Throat and Radiation impedance of horn *In the future, HWd should be assigned here |

25 | W | 3/13 | *Guest speaker Jack Buser; Senior Director, PlayStation Digital Platforms
Sony Computer Entertainment America | |

26 | Th | 3/14 | Exam II, Thur @ 7 PM in EVRT 241 | |

F | 3/15 | No class (Exam II) | ||

12 | M-F | 3/18-22 | Spring Break | |

27 | 13 | M | 3/25 | *Lecture: How does the middle ear work?*HWe due April 8, 2013; Starter files for middle ear simulation (txline.m Δ,gamma.m Δ); Similar to HW3 of ECE537 |

Part III: Signal Processing (3 lectures L27,29-30; 2 Labs: L28,31;) | ||||

28 | W | 3/27 | Review of the Fourier Transform [e.g.: {$\delta(t) \leftrightarrow 1$}, {$\delta(t-T) \leftrightarrow e^{-j\omega T}$}; {$1\leftrightarrow 2\pi\delta(\omega)$}, etc.] *Notes on the Laplace {$\delta(t)$} function (i.e., {$u(t) \equiv \int_{-\infty}^t\delta(t)dt$} it a function? pdf) | |

29 | F | 3/29 | No class due to lab | |

30 | 14 | M | 4/1 | *Periodic Functions: {$f((t))_R \equiv \sum_n f(t-nR)$} with {$n \in \mathbb{Z}$} and their Fourier Series {$f((t))_R = \sum_k f_k e^{jt 2 \pi k/R}$}; Sampling and the Poisson Sum formula {$\sum_n \delta(t-nR) \leftrightarrow \frac{2\pi}{R}\sum_k \delta(\omega- k\frac{2\pi}{R})$} or in a a more compact form: {$ \delta((t))_R \leftrightarrow \frac{2\pi}{R} \delta((\omega))_{2\pi/R} $} |

31 | Marcelo | W | 4/3 | *One-sided FTs: Hilbert Transform {$u(t) \leftrightarrow \pi\delta(\omega)+{1 \over j\omega}$} and its Dual {$\delta(t) +\frac{j}{\pi t} \leftrightarrow 2 u(\omega)$}* Cepstral analysis and its applications to Speech processing |

32 | F | 4/5 | No class due to lab | |

Part III: Hearing and Hearing Aids (5 lectures L27,29-30,32-33; 2 Labs: L28,31,34;) | ||||

33 | 15 | M | 4/8 | * Lecture: Middle ear as a delay line * Read Rosowski, Carney, Peak (1988) The radiation impedance of the external ear of cat: Measurements and applications (pdf)HWe due |

34 | W | 4/10 | *The intensity JND and Loudness: Weber's, Fechner's and Steven's Laws; Brain Image | |

35 | F | 4/12 | Final lab | |

36 | 16 | M | 4/15 | *How does a microphone work?; Sigma-Delta 24 bit oversampled with noise shaping analog to digital converters: A light-weight overview. |

37 | W | 4/17 | *Noori Kim Lecture: Modeling a hearing aid (ear bud) receiver | |

38 | F | 4/19 | *Guest Lecture: Lorr Kramer on Audio in Film | |

Part IV: Selected Topics (5 lectures L38-40,42-43, 1 Lab: 41) | ||||

39 | 17 | M | 4/22 | *History of Acoustics, Part II;History of acoustics History & (Hunt Ch. 1) *Newton's speed of sound; Lagrange & Laplace+adiabatic history *Discussion of your final project on Loudspeaker measurements: Content, format, style, grading (ECE403 project) |

40 | W | 4/24 | *Lecture Final summary of how a loudspeaker work | |

41 | F | 4/26 | Ryan group presentation | |

42 | 18 | M | 4/29 | *Austin group presentation *Steven group presentation *Hand in preliminary version of final paper on loudspeaker analysis |

43 | W | 5/1 | *Group 4 presentation (Marcelo) *Room acoustics: 1 wall = 1 image, 2 walls = {$\infty$} images; 6 walls and arrays of images; simulation methods pdf; Is a room minimum phase and thus invertable? djvu | |

Tr | 5/2 | Reading Day; Final project due by midnight: Please give me both a paper and pdf copy. NO DOC files | ||

- | F | 5/3 | Final Exams begin (Our final is the Lab project paper on loudspeakers) | |

Not fully proofed beyond here |

- The textbook is
**Electroacoustics: The Analysis of Transduction, and Its Historical Background**by Frederick V. Hunt. ISBN 0-88318-401-X. - Chapters 2 and 3 of the textbook are available here.
- You will need the DjVu viewer to read/print it. This can be found at: viewer. There are two DjVu versions. Either should work fine: traditional version and the open source version djview4 (recommended).

- The final grads were computed as follows: Each homework counted for 5 points. The two exams were each worth 25 points, for a total of 50 points. The final was broken down into 33 topics each worth 30/33 points, for a total of 30 points. This all adds to 100 points. Example: Score = 0.2*mean(HW)+.5*mean(Exams)+Final (within 1 point due to rounding and normalization).

- UIUC Physics 406
*Acoustical Physics of Music*Lecture Notes; This popular course provides a*very*different approach to many of the same topics we discuss in ECE403 and in ECE537. - HP scattering-matrix application notes pdf Δ, link
- A Vinyl record grove magnified 1000 times jpg Δ image
- Stiff piano strings by Richard Feynman djvu Δ
- Old guitar strings by Jont B Allen (1976) "On the aging of steel guitar strings"; Catgut Acoustical Society Newsletter, Nov., Vol 26, pp 27-29 (pdf)
- Audio projects that failed (it seems the website failed. Toobad it was great!)
- Q sound 3D audio
- Neural Audio DTS
- Holosonics Nonlinear-Ultrasonic Loudspeaker
- Passive Radiator speaker
- Conversion tables for 2-ports (page 1) and ABCD tables from Pipes (pages 2-3): djvu
- You can use SYSRES (windows zip, linux-bin) to take frequency response measurements at home.
- Network Theory Postulates
- Nonlinear acoustics: Bernoulli's Equation and conservation laws Navier-Stokes
- 3D Middle ear and cochlea view
- AAC+ encoding Slate article
- All-pass filters: a helpful explanation
- Prof. Beauchamp's ECE 403 Class Notes from Spring 2007
- Prof. Haken's Continuum Fingerboard
- Coursera
**Introduction to Digital Sound Design**

Powered by PmWiki