A Guide To Multi‑miking

Using more than one mic on a source can expand your sonic horizons — but it can also lead to problems. We explain when multi‑miking is and isn’t a good idea.

It’s easy to understand why multi‑miking is such a hot topic amongst project‑studio recordists. Not only can it offer enormous tone‑sculpting power while retaining lots of mixdown flexibility, but it also provides a welcome justification for buying lots of shiny new microphones. However, this technique can also backfire easily, too, because using extra mics introduces more opportunities for mistakes and complications. Indeed, having mixed hundreds of project‑studio multitracks myself (including plenty for Sound On Sound’s own Mix Rescue column), I can attest that small‑studio engineers frequently sabotage themselves with their multi‑miking methods, slowing down the production process and compromising the quality of the final mixdown.

So in this article, I’d like to suggest how to avoid some of the most common pitfalls, so you can get the best out of multi‑miking.

What Else Does The Sound Need?

I’ll be talking specifically about multi‑miking for tone, as opposed to stereo miking (which necessarily uses multiple mics). And probably the most common misconception about this sort of multi‑miking is that it’s some kind of panacea for getting good recorded tones. When you put up just one mic it’s pretty obvious that you have to pay attention to how it sounds, but somehow the very presence of more than one mic seems to lull far too many people into a false sense of security, so that they switch off their ears under the assumption that they can leave the sonic decisions until mixdown.

But the reality is that there are many more bad microphone positions than good ones, especially when you’re working with budget mics and in untreated acoustic environments. I’d estimate that roughly three quarters of the initial microphone choices and/or positions on any project‑studio session usually need adjusting in some way if you’re going to achieve genuinely workable recorded results, so having two or three mics on the go certainly doesn’t guarantee that any of those mics will actually sound any good! For example, one of the most challenging Mix Rescue remixes I ever tackled featured a triple‑miked acoustic guitar recording where all the mics sounded pretty awful, which made it a nightmare to salvage anything usable. And I’ve lost count of the number of drum kit recordings where I’ve immediately thrown away the additional ‘subkick’ mic (where you basically record the output of a speaker cone hanging in front of the kit) at mixdown because it offered nothing but completely inappropriate low‑end flab.

No matter how many mics you put up at once, it’s paramount that you listen to each one of them critically to ensure they’re actually contributing something useful.

So, no matter how many mics you put up at once, it’s paramount that you listen to each one of them critically to ensure they’re actually contributing something useful. A great way to discipline yourself to do this is first to put up just one mic, and to concentrate on trying to capture the whole sound through that. Only once you’ve given that a proper shot should you then ask yourself: “What else does the sound need?” You may be surprised how often the answer is, “Er... nothing, really!”, in which case it’s perfectly OK not to put up any more mics! But if you do identify some element of the sound that needs extra support, then you’ve immediately got a head start in terms of deciding what mic to add next and where to put it.

Let’s say you’ve already got a dynamic mic right over your guitar cab’s speaker cone delivering plenty of upper‑midrange bite, but you want more solidity or warmth to the tone. It stands to reason that you’ll probably want your second mic to be smoother‑sounding (perhaps a neutrally voiced large‑diaphragm capacitor or a ribbon), and you might want to place it off‑centre to the cone, or a couple of feet away — or even around the back of the cab!

This basic principle is probably most frequently forgotten when multi‑miking drum kits. I often hear overhead mics covered in thrashy hi‑hat, but with dull‑sounding snare ambience. Then, when I investigate the other drum channels, I find there’s a completely unnecessary mic on the hi‑hat, while the snare has only a close mic on the top head that goes ‘donk’! Where the hell is the final snare sound supposed to be coming from? Just listening to the overheads and asking, “What else does the sound need?” could have headed off this problem, perhaps by repurposing the hi‑hat close mic under the snare....