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I Heard It Through The Grapevine

Recording is an imperfect process, and all the bad information out there is not making things any better.

By Barry Hill June 26, 2017

I was reading a pretty good article the other day on miking, and it’s humming right along until the writer suggests intentionally using the off-axis pickup of directional mics to capture part of a choral ensemble.

What? And I can’t tell you how many wacko versions of XY stereo technique I’ve seen not only on the web but in books as well.

What’s iffy with the choir miking plan? Directional microphones are, well, directional because they attempt to reject sound coming from behind and beside the mic.

This is an imperfect process, and as sound originates from different locations, the mic’s internal delay chambers are trying to reduce it through cancellation at the diaphragm. There’s no way to have a clean cut-off zone, and since different frequencies have different wavelengths, the result varies.

So this other stuff suffers in frequency response, making it sound weird or colored (it’s actually called off-axis coloration). The point is that it doesn’t sound normal from back there, so we usually try to avoid it as much as possible.

Back to the XY problem, proper stereo mic technique is important to reduce phasing and maintain imaging between the channels. There’s, for sure, some questionable information and advice out there. Why is this?

Remember the game where you say something to the person next to you, and in turn, he relays that on down the line? When the first and last people compare messages, it’s always funny how badly things went haywire along the way.

Well, in a discipline such as audio, this phenomenon is not so hilarious.

Decades of discovery and invention have been invested into building a body of knowledge we rely on as engineers. Yet a great majority of folks have no idea where it comes from, simply doing a quick search on the web or tech forum. While some of this information is accurate, a great deal of it has become mutated as we get farther from our original sources.

Many years ago I looked up John Woram, author of such classic texts as The Recording Studio Handbook and Sound Recording Handbook. For many of us, these were our school textbooks that provided a grounded reference in the field. When I began teaching recording, I naturally looked to adopt the studio handbook for class, but couldn’t find it anywhere.

The response when I reached out to John, who had left audio some time earlier, was surprising. Seems his publisher insisted the books were not useful since students complained they were “too hard.” Really. So the books were shelved, so to speak, and have been out of print ever since.

I’m not saying everything you find today is bad – solid books and resources continue to be published regularly – but much of it is nowhere near as in-depth, grounded, and accurate as that from John Woram, John Eargle, Bruce Bartlett, and the like. And many of the tech forums? Don’t even get me started.

Now, is it wrong to use a mic off-axis?

Not necessarily, but it really depends on the context.

Experienced engineers understand there are no rules, but they also have experience that provides them with reference and perspective. They know the difference between “correct” and “not-so-much,” and then make decisions based on what they prefer for each situation.

Novices, however, have no such reference and background to hear the distinction.

I get this all the time with first-year students who are giddy with excitement over how awesome their mixes sound. But what they take as fullness or “air” is actually mud and extra crispy highs. The reverb that gives it a “live” sound probably needs two seconds and 6 dB shaved off. What they need is time-on-task and guidance to help them learn the difference, but this requires accurate fundamentals along the way.

All audio professionals and educators must recognize the issue, ensure that we always refer back to original, accurate sources, and find ways to get these vital concepts to the next generation of engineers, including (especially) students.

So, any bids on my Woram collection?

About Barry

Barry Hill
Barry Hill

Barry Hill, D.Ed. is a long-time audio educator and engineer who serves as professor and director, Audio & Music Production, at Lebanon Valley College in Pennsylvania.
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