Double Qualification in Engineering Studies in Audio-visual Systems and Multimedia

Double Degree in Engineering Studies in Audio-visual Systems and Multimedia

La Salle Campus Barcelona offers 5 double degrees in the ICT Engineering and the Business Management field. With the double degrees, you can finish the university studies in 5 academic years with two official degree qualifications

Acoustics Engineering I

In which frequencies do the interior of a car vibrates easier? How is the vibration from the bogie´s wheels transmitted to the interior of a train? How may the noise that an airplane´s passenger perceives be reduced? Can we predict the noise that we will perceive at the 4th floor if there is a discotheque at the 1st floor? What are the measurements necessary to obtain this information? How do measurement devices such as microphones, accelerometers and multichannel-spectrum analyzers work? How is the directivity and sensibility of a loudspeaker characterized? How is a measurement protocol of any acoustic parameter set up from the definition of the transducer to the analyzer configuration? How are the material´s acoustic properties for example, the acoustic absorption coefficient measured? To answer these questions inquired by acoustic engineers that work in different areas such as automobiles, trains, aerospace sector, electronic acoustics, environmental acoustics or instrumental acoustics, it is necessary to know several analysis, measurement and prediction methods and techniques, both theoretical and experimental. During the first semester of the subject Acoustics Engineering Theory and laboratory I we focus on the theoretical aspects of some of them. By other hand, during the second semester, the subject becomes more practical and experimental. Its objectives are to introduce basic concepts of acoustic measurements and to consolidate the theoretical concepts studied during the first semester and in the subject of Fundamentals of Acoustic and Audio. This semester takes place in the Acoustics Laboratory using the anechoic and reverberation chambers and all the necessary instrumentation. By means of the accomplishment of 5 practices, the student will acquire basic knowledge related to: measurement protocols, signal and system analysis, acoustic absorption coefficient measurement in the reverberation chamber, experimental modal analysis and loudspeakers characterization.
Type Subject
Tercer - Obligatoria

Titular Professors

Previous Knowledge

Fundamentals of Acoustic and Audio



1. Basic concepts to solve acoustic and vibration problems [2h]
1.1. Decibel scale
1.2. Individual contribution of each source
1.3. Frequency information
1.4. Noise and vibrations: two aspects of the same problem
1.5. Summary
2. Modal analysis
2.1. Introduction
2.2. Analytic and experimental modal analysis
2.3. 1 degree of freedom system in free regimen
2.4. 1 degree of freedom system in forced regimen
2.5. 2 degrees of freedom system and N degrees of freedom
2.6. Modal parameters, modal vectors, participation factors, orthogonality and modal coordinate
2.7. Structural and proportional muffling
2.8. Estimation methods of modal parameters of 1 degree of freedom
2.9. Estimation methods of modal parameters of multiple degrees of freedom
2.10. Model validation
2.11. Introduction to operational modal analysis
2.12. Summary
3. Transmission-channels analysis [12h]
3.1. Frequency response functions
3.2. Definitions and hypothesis
3.3. Coherent and energetic factorization
3.4. Function matrix of volumetric velocity transference
3.5. Mechanic forces measurement with the operative system
3.6. Measurements with the operative system
3.7. Wrongly conditioned matrix
3.8. Introduction to operational transmission channels analysis
3.9. Summary

4. P1. Signal and System analysis
4.1. Signal analysis
- Introduction to the two-channel analyzers BK 2034/2035 and Symphonie
- Spectral analysis: FFE, temporal resolution, frequency resolution, FFT, window, amitjanament, zoom, trigger, auto-rank
- Kinds of signal and measurement unities
- Calibration of a measurement chain

4.2. System Analysis
- Impulsion excitation
- Excitation with broadband signals
- Stimulators of a system´s frequency response
- Measurement coherency
- Cross-correlation

5. P2: Loudspeakers characterization
5.1. Frequency answer
- Introduction to the two-channel analyzer BK Pulse
- Loudspeakers´ frequency response measurement
- Loudspeakers´ directivity measurement
- Diffraction

6. P3: Attenuation coefficient in the reverberant room
6.1. Acoustic attenuation of a material in the reverberant room coefficient measurement protocol
- Introduction to the multi-channel analyzer NetdB
- Reverberant time measurement by the uninterrupted source method.
- Measurement of the acoustic attenuation coefficient of a material according to the measurement regulation UNE-EN 354
- Calculus sheet in Excel
6.2. Acoustic field diffusion
- Acoustic field diffusion qualification: sound pressure level deviation
- Room docking

7. P4. Material mechanical parameters
- Introduction to Shaker BK4009 and the accelerometers and charge analyzers.
- Young module measurement
- Muffling measurement
- Measurement from the theory of the modal parameters extraction based on the SDOF methods: peak picking and circle fitting
- Orbest method measurement

8. P5: Modal Experimental Analysis
- Introduction to the multi-channel analyzer OR38 and to the accelerometers ICP
- Impact hammer
- Analytic calculus of own modes
- Spatial sampling
- Parameter extracting methods
- Own modes forms visualization


1st semester

1. Magisterial classes
2. Problem classes

2nd semester

1. Magisterial classes´ contents exposition

Along the course, the professor will explain the subject´s basic theoretical concepts through magisterial classes. In these classes the professor will also solve exercises to apply the explained concepts.

2. Practices at the Acoustic Laboratory

Through the semester, the students do 5 practices in groups. The first day of the practice the professor explains the objectives and the basic concepts. Through the experimentation, students solve the exercises and experiments proposed. The second day of the practice, the professor will ask some questions to his pupils to make sure that they have understand the continents.
Between the two days of the practices, students may go to the laboratory to finish the proposed exercises.


1st Semester

Written exams at the end of the second semester (2~3h)
Continuous evaluation based on exercises and practices solved individually or in group (two additional notes to the exam each semester)

2nd Semester

The evaluation is made from an individual practical exam, a theoretical exam and the questions asked at the end of the practices.

The global grade is calculated with as explained below:

Theoretical exam = 15%
Practical exam = 70%
Questions about practice = 15%

The final exam is averaged if the Practical Exam grade is ≥ 3.5

2nd semester final grade = 0.70 Practical Exam + 0.15 Theory + 0.15 Questions

The attendance to the practice is obligatory. The practical sessions are 3 hours long and each practice has two sessions.
The students have a timetable to access the laboratory after class hours.
Practices are carried out in groups. Depending on the number of students, the groups may be formed by maximum three persons. Students must bring printed and read the practice statement corresponding to that week.

Subject evaluation

The evaluation of each semester is independent. The subject is passed if the Final Grade is equal to or higher than 5.

Final Grade = 0.50 Final Grade 1st Semester + 0.50 Final Grade 2nd Semester
The previous medium value will be only applied in the event that the grades of each semester are higher or equal than 4,5.

In the event that only one semester is passed, the grade will be keep for the next semester, but not for the following.

Evaluation Criteria
Basic Bibliography
Additional Material

Semestre 1
Temes 2 i 3:
- D.J. Ewins, Modal testing: theory and Practice (Brüel & Kjaer) (1986)
- Z. Fu and J. He, Modal Analysis (Butterworth-Heinemann) (2001)
- W. Heylen, S. Lammens and P. Sas, Modal Analysis Theory and Testing (KUL Press) (1997)
- Transfer Path Analysis: the qualification and quantification of vibro-acoustic transfer paths, LMS

Semestre 2
- C.M. Harris and Crede, Shock & Vibration Handbook, Ed. McGraw-Hill, 1988.
- L. Beranek, L. Vér. Noise and Vibration Control Engineering, Ed. John Wiley & Sons, 1992.
- C. Hopkins, Sound Insulation, Ed. BH, 2007
- M.J. Crocker. Handbook of noise and vibration control. Ed. John Wiley & Sons, 2007