Mic It! Microphones, Microphone Techniques, and their Impact on the Final Mix

Ian Corbett
Focal Press
978-0-415-82377-7 | October 2014
Taylor & Francis Catalogue

The practical task of sound recording incorporates many distinct activities. Microphone choice and placement, audio editing and effects processing, mixing, mastering, and the preparation of various different types of physical and online distribution media, are all topics that might fall under this heading, as are planning and running recording sessions, and successfully negotiating interpersonal relations between musicians, engineers, and producers. Add to this the broad range of theoretical knowledge required—on the premises of analogue and digital audio, on acoustics and sound propagation, on stereo imaging, on the physiological and psychological bases of sound perception—and it can readily be seen that the task of addressing the subject of ‘sound recording’ in a book must necessarily involve strict decisions about the range of topics to be covered. Such decisions will invariably involve a trade-off between breadth and detail.

Some books on sound recording, such as Steve Savage’s The Art of Digital Audio Recording (Savage: 2011), cover ‘a little bit of everything.’ Huber and Runstein’s Modern Recording Techniques (Huber & Runstein: 2013), similarly, describes the entire process, from first principles to product manufacture. First published in 1974 and now in its 8th edition, Huber and Runstein’s book also incorporates an historical perspective (e.g. a chapter on the analogue tape recorder). These general guides provide an excellent perspective for the beginner seeking an overview of the entire sound recording process, but the trade-off is, of course, that none of the topics is covered in any great detail.

Another approach is to focus more narrowly on one specific aspect of the sound recording process, as in Moylan’s Understanding and Craft the Mix (Moylan: 2014) and Katz’s Mastering Audio: The Art and the Science (Katz: 2014). Such textbooks provide more detailed, topic-specific guidance on individual stages of the sound recording workflow, and are helpful in developing subject-specialism in both novice and intermediately experienced practitioners. The trade-off, conversely, is that the precedent and subsequent stages of the recording process are either omitted or only briefly treated.

Ian Corbett’s Mic It! Microphones, Microphone Techniques, and their Impact on the Final Mix falls into this latter category of textbooks that deal with a specific part of the sound recording process in detail. Corbett’s focus is microphone choice and placement, and within that scope he details a range of practical techniques and approaches that are applicable to the recording of popular, jazz, and classical music ensembles. His distinctive approach is to emphasise how microphone choice and placement decisions have knock-on effects in the next stage of the sound recording workflow, mixing. His stated aim is ‘to give you the knowledge to record tracks that sound good, and sound the way you anticipate using them in the mix’ (Corbett: 2014, p.312).

The first eight chapters outline, in ‘overview’ style, the general principles that underpin microphone use. Chapter 1—the only chapter in the book that is purely theoretical—covers the fundamentals of sound, analogue and digital audio, and (very briefly) the human hearing system. Chapter 2 invites the reader to consider what might constitute ‘Good Sound’ in recordings, and covers topics such as frequency and amplitude balance, clarity and intelligibility, and stereo image. Chapter 3, ‘About Microphones’, discusses the various microphone types—dynamic, condenser, ribbon, boundary, etc.—and where and when they might be used, as well as outlining fundamental properties such as frequency and directional response, and potential issues such as the proximity effect. Chapters 4 and 5 describe, respectively, the principles and practicalities of EQ, and stereo imaging, while Chapter 6 provides a comparative account of a range of stereo microphone arrays, including XY, Blumlein, near-coincident, and spaced pair configurations as well as middle-side, Decca Tree, and binaural methods. Chapter 7, ‘The Effect of Microphone Position’, is an exploration of the ways in which microphone placement changes the sound characteristics of the recorded music, and includes discussion of perspective, spill, off-axis response, and the ratio of direct to reverberant sound. Chapter 8 highlights the influence of room acoustics upon the recorded sound, with some instructive advice on how to choose microphones that are appropriate for the room in question, and on how to improvise or cheaply construct acoustic treatments for use in home studios.

Chapters 9 to 12 describe how to apply the general principles covered in the preceding chapters to specific recording contexts. Each of these chapters outlines microphone techniques for a specific instrument or class of instruments: Chapter 9 focuses on vocals; Chapter 10, drums; Chapter 11, guitars, basses, and keyboards; and Chapter 12, strings, winds, brass, and percussion. These chapters are, roughly speaking, structured similarly. First, the role of the instrument (or vocal) in question is discussed: vocals tend to be the focal point in popular music; drums, often working in tandem with bass, are the ‘second most important’ instrument; guitars and keyboards provide texture and harmonic ‘filler’; and so on. Next, microphone techniques appropriate for the instruments in question are discussed. Finally, instrument-specific EQ suggestions are given.

Chapters 13 to 16 describe larger-scale scenarios that require the full range of techniques covered in the previous chapters to be assimilated. Chapter 13, ‘Beyond the Basics’, outlines a number of specific techniques can be applied creatively ‘to craft a piece of sonic art that draws the listener in, and is compelling to listen to’ (Corbett: 2014, p.254). This includes a more advanced discussion of compression, the effects of microphone distance, and how to make creative use of room characteristics and comb-filtering using multiple microphones or room mikes. Chapter 14, ‘Setting up the Studio’, describes the planning and practicalities involved in running a recording session, while Chapter 15 focuses on recording larger ensembles such as full orchestras and choirs. Chapter 16, ‘Putting it All Together’, deals with what happens after all the microphones have been set up, and covers topics such as putting together headphone mixes and click tracks. Finally, there is an interview-based chapter, ‘Tips from the Professionals’, which offers a brief but interesting selection of personal insights from working practitioners. There are sound examples throughout the book—accessed via the companion website—to illustrate key points and techniques.

Given Corbett’s focus, it is not particularly surprising that Chapter 7, ‘The Effect of Microphone Position’, is where this book really starts to come into its own. Here, Corbett embarks upon a detailed and thorough exploration of how microphone placement changes the qualities of the recorded sound. He conveys a vivid impression of the many interacting factors, such as how adjusting the distance between microphone and sound source results in simultaneous changes in perspective, ratio of direct to reverberant sound, and the influence of off-axis response. What stands out about Corbett’s prose is how lucidly such interrelated trade-offs are explained, in a way that is concise and easy to follow. From this point onwards, Corbett systematically describes how the various different attributes of a mix—such as frequency balance, focus and amplitude balance, and even stereo imaging—can be contrived via acoustic means, or via microphone choice and placement, rather than by post hoc processing.

If there is a weakness in this book, it is probably that some of the underlying theoretical concepts are slightly inadequately covered. The opening chapter is probably the weakest. The chapter serves its purpose—it covers all of the necessary ground, for certain—but skips over detail in a way that is sometimes problematic. Concepts such as decibels, dynamic range, harmonics, standing waves, and the Nyquist frequency, realistically, require a fuller explanation than is provided here, particularly if they are to be understood by the uninitiated student; presumably one of the major targets of this book. In addition, some of the terminology used is not explained, and the inclusion of a glossary would have been useful to remediate this.

These are comparatively small criticisms, though, and there is much to recommend this book, which—in fairness—does not claim to be a theoretical reader. The advice that Corbett has to offer is consistently pragmatic, and generally presented in a way that encourages critical engagement, rather than rote learning, on the part of the reader. Topics are covered in a satisfying level of detail, and no prior knowledge is assumed (previous comments on the theoretical material excepted). Throughout the book the prime importance of listening is repeatedly emphasised, and novice practitioners are encouraged to learn the rudiments first, listening to and emulating existing recordings in a range of different idioms, just as ‘musicians practice scales as a prerequisite to finding their own style’ (Corbett: 2014, p.50). Most of the chapters include practical exercises, and all contain a broad range of practically-oriented insights. Such exercises are clear and easy to follow, and structured so as to strike a balance between practical exploration, conceptual understanding, and critical evaluation of the various techniques described.

Corbett’s ethos comes across loud and clear: capture the sound that you want at the recording stage, thus minimising the need for later intervention. Post hoc processing should be regarded as a last resort: wherever possible, a ‘natural acoustic alternative’ (Corbett: 2014, p.100) should be found prior to recording. This might include a combination of microphone choice and placement, careful selection of the recording venue, experimentation with the positioning of instruments and performers within it, and/or adjusting the acoustic with barriers and gobos. When post-processing truly is unavoidable—as it sometimes is—it should be kept to a minimum.

The sound examples are worth briefly mentioning. These are abundant (171 individual examples are provided), good quality, and extremely helpful in illustrating key points and techniques. Particularly helpful are those examples that illustrate the ineffective use of a particular technique, for example a recording that demonstrates the effects of over-compression on a snare drum recording (‘The life is sucked out of the sound’ [Corbett: 2014, p.255]).

The strength of Corbett’s book is the level of detail and attention paid to this one part of the recording process, microphone placement. This sets it apart from other practical recording guides that cover the entire process from recording through to mastering, and hence cover each topic only relatively briefly. Furthermore, Corbett’s detailed focus on shaping the mix through microphone technique, avoiding post hoc processing, provides an interesting and original perspective that differentiates his book from others that address the practical aspects of microphone use. The trade-off in this detailed focus, of course, is that Corbett does not tell you everything that you need to know about sound recording, and hence his book will be best used in combination with others. Rumsey & McCormick’s Sound and Recording (Rumsey & McCormick: 2014), Campbell & Greated’s The Musician’s Guide to Acoustics (Campbell & Greated: 2001), and Rayburn’s edition of Eargle’s Microphone Book (Rayburn: 2012) provide excellent accounts of the theoretical and conceptual aspects, the latter focusing on microphones specifically. Moylan’s Understanding and Crafting the Mix (Moylan: 2014) and Bob Katz’s Mastering Audio (Katz: 2014) cover the practical aspects of (respectively) mixing and mastering in detail. While we’re at it, Mark Katz’s Capturing Sound (Katz: 2010), Dogantan-Dack’s Recorded Music (Dogantan-Dack: 2008), and Chanan’s Repeated Takes (Chanan: 1997) would provide a useful critical and philosophical counterpart to learning the practical techniques. In combination with other text books such as those just suggested, Corbett’s book would make an excellent addition to any sound recording course reading list, or indeed to any amateur recording enthusiast’s bookshelf.

Bibliography

Campbell, M. and C. Greated (2001) The Musician’s Guide to Acoustics, new edition. Oxford: Oxford University Press.

Chanan, M. (1997) Repeated Takes: A Short History of Recording and its Effects on Music. London; New York: Verso.

Corbett, I. (2014) Mic It!: Microphones, Microphone Techniques, and their Impact on the Final Mix. Burlington, MA: Focal Press.

Dogantan-Dack, M. (ed.) (2008) Recorded Music: Philosophical and Critical Reflections. London: Middlesex University Press.

Huber, D. and R. Runstein (2013) Modern Recording Techniques, 8th edition. New York: Focal Press.

Katz, B. (2014) Mastering Audio: The Art and the Science, 3rd edition. Burlington, MA: Focal Press.

Katz, M. (2010) Capturing Sound: How Technology Has Changed Music, revised edition. Berkeley: University of California Press.

Moylan, W. (2014) Understanding and Crafting the Mix: The Art of Recording, 3rd edition. Burlington, MA: Focal Press.

Rayburn, R. (2012) Eargle’s Microphone Book: from Mono to Stereo to Surround: a Guide to Microphone Design and Application, 3rd edition. Oxford: Focal Press.

Rumsey, F. and T. McCormick (2014) Sound and Recording: Applications and Theory, 7th edition. Burlington, MA: Focal Press.

Savage, S. (2011) The Art of Digital Audio Recording: A Practical Guide for Home and Studio. New York: Oxford University Press.