May 03, 2012, by Keith Clark
The Audio Expert, a new book by Ethan Winer, exhaustively covers a plethora of important technical aspects of audio. But it goes much further, discussing and explaining the relationship between audio and a wide range of closely related factors. In short, it challenges you to think, to seek a deeper understanding.
Just released by Focal Press (and available here), I received an advance copy and have had a hard time putting it down. Winer, who has worked with audio for more than 40 years, is a mix engineer musician, product designer, author (and more), and in 2009, he presented the Audio Myths seminar at the AES Convention in New York that’s still generating buzz.
I recently caught up with him to discuss the book as well as a range of other topics.
KC: What was your primary motivation for writing the book?
EW: Two reasons – one is to dispel the many myths I see repeated endlessly in audio magazines and web forums. Most aspects of audio science have been understood fully for more than 50 years. Yet some people still believe that competent wires can sound different, that typical amounts of phase shift are audible, that jitter is a problem, that digital “summing” in DAW software is somehow flawed, and so forth.
Almost daily I see posts in audio forums by people with limited funds asking if they really need to spend a lot for a microphone, preamp, converter, or external summing box to get professional results. So my goal is as much consumerism as education, to help people spend wisely.
The other reason is to explain how audio really works to those who are interested. Forty years ago, recording engineers were as much “real” engineers as they were recordists. Back then, most knew how to solder up a patch bay and align a tape recorder, and many could read schematics and do at least minor repairs. George Massenburg is a perfect example – he’s renowned for the quality of his recordings, as well as for designing the first parametric equalizer.
When I started recording professionally in the 1970s, audio magazines included technical articles and DIY plans, and manufacturers were proud of their high fidelity and provided specs for distortion and frequency response. Today, a loudspeaker review is likely to state the size of the woofer but not its frequency response, which of course is what really matters! And you almost never see distortion specs or off-axis response. If an active loudspeaker includes distortion specs, it’s usually for the power amplifiers only, not the complete system.
Many mix engineers have the talent to make music sound great, but without understanding the engineering and science behind the gear they use. I appreciate that some people don’t care at that level, but many do. In my estimation, the pro audio press has let us down in this regard, dumbing down content, and even perpetuating many of the same myths you read in hi-fi type magazines.
Your experience is more with recording than live sound. What’s the value of the information you’re providing for the live sound practitioner?
The Audio Expert is a comprehensive “reference” type book covering all aspects of audio, so there’s plenty for everyone – even interested audiophiles. It’s written for people who want to understand audio at the deepest, most technical level, but is presented using plain-English explanations and mechanical analogies with minimal math.
Besides describing how many different audio devices are used, it also explains how they work internally. The book brings together the concepts of audio science, aural perception, musical instrument physics, acoustics, and basic electronics, showing how they’re intimately related. So while I don’t address directly the challenges facing live sound engineers, there’s a huge amount of educational content. It’s definitely not a “Dummies” type book for beginners!
If you could recommend one chapter as the “must read” of the book, what is it, and why?
Perhaps most important is explaining in great detail how fidelity is defined, with included audio examples people can play on their own systems to determine at what level distortion and other artifacts are audibly damaging. This is addressed mainly in Chapters 2 and 3, though this type of information is sprinkled liberally throughout the book.
Besides the 65 demo audio files available on the book’s web site, there are also 31 videos and five audio-related software programs.
What’s the single biggest misconception or “myth” about audio?
The two biggest myths are probably that there are aspects of audio fidelity that “science” hasn’t yet learned how to measure, and that listening is a more reliable way to assess the quality of gear than measuring. I see magical thinking all the time in audio forums, but it’s easy to prove that everything affecting the fidelity of audio devices is already known.
A spectrum analyzer can display artifacts 100 dB below the music, and is highly reliable and repeatable, versus human hearing that varies from moment to moment, and is influenced by the masking effect. Many types of distortion and other artifacts can be very difficult to hear, even when they’re only 40 dB below the music.
What sources proved most valuable as you wrote and assembled 650-plus pages of significant technical information provided in the book? How did you fact check and verify?
The book actually totals 739 pages when including the three bonus chapters online. I’ve been involved with audio for many years as a recording engineer, circuit designer, and computer programmer, so I already had a solid grasp of the science. But I did learn a few things! I was fortunate to get advice from microphone expert Bruce Bartlett and loudspeaker expert Floyd Toole.
Another friend, electronics engineer John Roberts, read my entire manuscript as I wrote it, and audio expert Mike Rivers did the technical review. All of these people provided invaluable suggestions and fact checking.
How do you clearly separate what is objective in audio versus what is subjective?
Subjective preference is impossible to define, so I don’t even try. I do address some aspects of preference, such as the perceived improvement after adding acoustic treatment. But mostly I address the science of audio, and explain how audio circuits and their plug-in equivalents are used and how they work internally.
It’s impossible to “measure” the quality of a piece of music, or assess one’s enjoyment. But it’s absolutely possible to assess fidelity, even when a perfectly clean sound is not the artistic goal.
In your view, what are the differences between analog and digital audio in terms of sound quality?
First we have to define what is meant by analog and digital. “Analog” encompasses both audio hardware such as equalizers and compressors, as well as the recording mediums of magnetic tape and vinyl records.
Digital audio refers to both the recording medium and software effects. Analog gear can be very high quality, with distortion and noise low enough to not hear, and a frequency response flat enough to not matter.
Gear that meets these criteria is considered audibly transparent, such that it’s difficult to notice a change in quality after passing through the device.
Digital plug-ins have a slight advantage because their transparency is dictated entirely by the resolution of the math used to perform the needed calculations. Most modern software processes audio data using 32-bit floating point numbers. This is potentially cleaner than any real-world electronic circuit.
Of course, every computer sound card and outboard A/D/A converter has analog input and output sections, and these ultimately limit the fidelity possible. But many converters are audibly transparent. So the real answer is that both analog and digital can have acceptably high fidelity when implemented properly.
Another important factor falls outside the context of “sound quality” – intentional subtle distortion used for effect to add faux clarity to a track or complete mix, or as “glue” to make a mix sound more cohesive. A compressor with both the attack and release times set very fast also adds distortion that is useful in some contexts. These effects can be implemented effectively using either digital or analog technology.
What are the best ways to learn the essential principles of audio?
The best way to learn is by doing. It also helps to have knowledgeable friends, whether in person or a web forum. Of course, the downside of web forums is having to sort through many disparate opinions to separate fact from belief. But anyone who has basic audio software can easily try things for himself or herself.
Often I’ll see someone in an audio forum ask, for example, if they should compress before EQ or vice versa, or use EQ boost rather than cut – even though it would be trivial to just try it to find out for yourself firsthand!
If a tree falls in the forest and no one is there to hear it, does it make a sound?
For a much more detailed and interesting answer to that last question, be sure to check out The Audio Expert, published by Focal Press (ISBN: 9780240821009) and available here.
And, go here to read an excerpt chapter entitled Audio Fidelity, Measurements, And Myths - Part 1, provided exclusively to PSW.
Keith Clark is editor in chief of ProSoundWeb and Live Sound International.
Transcending Tech: A Conversation With Ethan Winer, Author Of “The Audio Expert”