xiPreface
When the first edition of the Handbook for Sound Engineers came out in 1987, it was subtitled the new Audio Cyclo-
pedia so that people who were familiar with Howard Tremain’s Audio Cyclopedia would understand that this is an
updated version of it. Today, the book stands on its own.
We have seen a tremendous change in the field of sound and acoustics since the first edition of the Handbook for
Sound Engineers came out. Digital is certainly finding its place in all forms of audio, however, does this mean analog
circuitry will soon be a thing of the past? Analog systems will still be around for a long time. After all, sound is ana-
log and the transfer of a sound wave to a microphone signal is analog and from the electronic signal to the sound wave
produced by the loudspeaker is analog.
What is changing is our methods of producing, reproducing, and measuring it. New digital circuitry and test equip-
ment has revolutionized the way we produce, reproduce and measure sound.
The Handbook for Sound Engineers discusses sound through seven sections, Acoustics, Electronic Components,
Electro-Acoustic Devices, Audio Electronic Circuits and Equipment, Recording and Playback, Design Application,
and Measurements.
When we listen to sound in different size rooms with different absorptions, reflections, and shape, we hear and feel
the sound differently. The Handbook for Sound Engineers explains why this occurs and how to control it.
Rooms for speech are designed for intelligibility by controlling shape, reflections and absorption while rooms for
music require very different characteristics as blend and reverberation time are more important than speech intelligi-
bility. Multipurpose rooms must be designed to satisfy both speech and music, often by changing the RT60 time
acoustically by use of reflecting/absorbing panels or by designing for speech and creating the impression of increased
RT60 through ambisonics. Open plan rooms require absorbent ceilings and barriers and often noise masking. Studios
and control rooms have a different set of requirements than any of the above.
There are many types of microphones. Each installation requires a knowledge of the type and placement of micro-
phones for sound reinforcement and recording. It is important to know microphone basics, how they work, the various
pickup patterns, sensitivity and frequency response for proper installation.
To build, install, and test loudspeakers, we need to know the basics of loudspeaker design and the standard meth-
ods of making measurements. Complete systems can be purchased, however, it is imperative the designer understand
each individual component and the interrelation between them to design and install custom systems.
With the advent of digital circuitry, sound system electronics is changing. Where once each analog stage decreased
the SNR of the system and increased distortion, digital circuitry does not reduce the SNR or increase distortion in the
normal way. Digital circuitry is not without its problems however. Sound is analog and to transfer it to a digital signal
and change it back to an analog signal does cause distortions. To understand this the Handbook for Sound Engineers
delves into DSP technology, virtual systems, and digital interfacing and networking.
Analog disk and magnetic recording and playback have changed considerably in the past few years and are still
used around the world. The CD has been in the United States since 1984. It is replacing records for music libraries
because of its ability to almost instantly locate a spot in a 70+ minute disc. Because a disc can be recorded and rere-
corded from almost any personal computer, disc jockeys and home audiophiles are producing their own CDs. Midi is
an important part of the recording industry as a standardized digital communications language that allows multiple
related devices to communicate with each other whether they be electronic instruments, controllers or computers.
The design of sound systems requires the knowledge of room acoustics, electroacoustic devices and electronic
devices. Systems can be single source, multiple source, distributed, signal delayed, installed in good rooms, in bad
rooms, in large rooms, or small rooms, all with their own particular design problems. Designing a system which
should operate to our specs, but where we did not take into consideration the proper installation techniques such as
grounding and common mode signal, can make a good installation poor and far from noise and trouble free. The
Handbook for Sound Engineers covers these situations, proper installation techniques, and how to design for best
speech intelligibility or music reproduction through standard methods and with computer programs.
The new integrated circuits, digital circuitry and computers have given us new sophisticated test gear unthought of
a few years ago, allowing us to measure in real time, in a noisy environment, and measure to accuracies never before
realized. It is important to know, not only what to measure, but how to measure it and then how to interpret the results.