Academic year 2015-16

Audio Equipment and Systems

Introduction

This course explores the physical and technological processes and technical systems used for capturing, recording and playback of sound. The course begins with a review of applied acoustics (eg sound pressure level, decibels, etc.) already studied in prior subjects but which are considered essential to follow the rest of the course. The course consists of theoretical blocks as following: (1) channel recording and playback. analysis of the acoustic environment and basics of electrical engineering; (2) systems and microphones for capturing sound; (3) speaker systems; (4) power and signal infastructure; (5) systems transmission and amplification systems; (6) digital audio systems. processing, protocols, storage.
In the practical parts recordings are made with different types of microphones by using different positions and various materials to study the acoustic frequency response, directivity and sensitivity of different transducers. Speaker responses (Thiele-Small parameters) and dual-channel analysis between different microphones are also analysed. 

Prerequisites

To take this course in the third year, it is assumed that the student has already completed the courses "Waves and Electromagnetism" (1st year), "Signals and Systems", "Engineering Acoustics", "Architectural Acoustics", "Electronic Circuits Media and Transmission "(2nd year)," Processing and Sound of Music "and" Systems Voice and Audio Coding "(3rd year). If that were not so,  basic knowledge of physics (mechanical and electromagnetic waves) is needed, as well as being familiar with the basics of audio signal processing (frequency, intensity level and sound pressure decibel etc.) and acoustics (wave propagation, reflection, etc.).

Associated competences

Skills to work in the subject as indicated in the curriculum of the degree

Instrumental skills 

G1: Capacity for analysis and synthesis.

G2: Capacity for planning and organization

G3: Ability to apply knowledge to analyze situations and solve problems.

G4: Ability to search and manage information.

G5: Ability to make decisions.

 

Interpersonal skills

G8: Capacity for teamwork.

 

Systemic skills

G11: Ability to apply flexibility and creativity acquired knowledge and adapt to new situations and contexts.

 

G12: Ability to progress in education and learning processes autonomously and continuously

 

 1. Acquire theoretical and practical knowledge of measuring equipment and the acoustic field reproduction.

2. Properly configure and install and audiovisual system in terms of power and signal infrastructure

3. Know the basic characteristics of different types of microphones (electrostatic electrodynamic, piezoelectric, etc.) to interpret a specification sheet, and to choose the most appropriate model for each type of recording.

4. Understand the importance of positioning a microphone and sound use of different materials to make different types of recordings.

5. Understand the problems related to sound playback in a room and the acoustic design of architectural spaces.

6. Understand the different scales of measurement (dBu, dBV ...). Knowing how to use a mixer and a digital multitrack recording system (such as ProTools).

7. Acquire knowledge about the production, post-production and exhibition audiovisual projects

Assessment

The evaluation is done for each of the activities that are part of the course: lectures, seminars and practical classes in the laboratory. The evaluation of the theory is done through a final exam. The evaluation of the practical exercices is done through reporting deliveries.

Contents

1. Fundamentals of acoustics. Audio Units and measurement equipment
• Energy, Power and intensity of acoustic waves
• Sound Intensity and Pressure levels
• Sound propagation
• Loudness and weighting curves
• Reflection, absorption, diffraction and refraction of sound waves
• Reverberation

2. Microphone technology
• Sensitivity, noise, dynamic range
• Frequency & transient response
• directionality and polar patterns
• transduction types: pressure vs. pressure-gradient mikes
• transduction types: moving coil, ribbon, piezoelectric, capacitor, electret

3. Technology amplification. Preamplifiers and power amplifiers
• Impedance
• Line input level (dBV and dBu)
• Sensitivity, Maximum power output and Gain
• Frequency response bandwidth and Power
• Distortion
• Crosstalk (between channels)
• Signal-to-noise ratio

4. Technology speakers and loudspeakers.
• Technologies: electrodynamic, electrostatic, piezoelectric
• Specifications: Frequency range, sensitivity, impedance, power, directivity
• Boxes & Bass-reflex
• Usage: Studio, Home studio, PA Headphones

5. Principles audio digital recording, editing, and mastering formats
• A / D and D / A conversion
• Digital recording, editing and mastering
• Digital Audio Formats and Interchange

Methodology

This course will combine the following teaching

• lectures given by the theory teacher
• seminars and practical classes taught by professor conducted laboratory practices
• independent practices carried out independently in groups of 3 or 4 students

In the theoretical study the concepts described in the corresponding section.

The seminar sessions will deepen into professional aspects of the subject. The laboratory sessions in groups are intendend to demonstrate in practice the concepts contained in the theory sessions.

Independent practical exercises will test students' ability to solve practical problems using standard devices such as microphones, stands and wiring, mixers and multitrack software.

Resources

List of basic bibliography (maximum 3 books) and supplementary materials that will be available from the Moodle webpage 

Textbooks

• Rumsey, F. And McCormick, T. (2009). Sound and Recording, Sixth Edition. Focal Press, Elsevier
• Ballou, Glenn, Ed. (2010). (2008). Handbook for sound engineers, 4th Ed. Focal Press, Elsevier
• Jamie Angus, David Howard. Acoustics and Psychoacoustics, 4td Ed. (2009). Focal Press, Elsevier

PDF slides will also be avalilable specifically designed to follow the course

Further reading

• Don Davis, Eugene Patronis. Sound System Engineering, 3rd Ed. Focal Press
• Ja Kadis. Ths Science of Sound Recording (2012). Focal Press, Elsevier
• Ray A. Rayburn. Eargle’s The Microphone Book, 3rd Ed (2011). Focal Press, Elsevier
• Douglas Self. Audio Engineering explained (2009). Focal Press, Elsevier
• Michael Talbot-Smith. Audio Engineer’s reference book, 2d Ed. (2001). Focal Press, Elsevier
• Glenn Ballou. A sound engineer’s guide to Audio Test and Measurement (2009). Focal Press, Elsevier
• Gary Davis, Ralph Jones. The YAMAHA Sound Reinforcement Handbook (1989). Hal Leonard