Friday, November 11, 2011

Engineering Drums Part Three: Drum Kit (Singular)? Or Drums, Etc. (Plural)?

As an audio engineer, how do you perceive the drum set? Is it a single instrument to you, or do you think of it as a collection of several individual instruments over which you want control? I ask this question, because your answer will determine how you approach miking drums, and, IMHO, how much success you will have presenting it to your audience, whether live or on record.

I think of drums as a single instrument. Just as a guitar is made up of a body, a neck, fretboard, frets, strings, bridge, nut, etc. to make the whole, so do the kick, snare, toms, and cymbals combine to become one overall instrument – one person plays a guitar, and one person plays a drum kit. Bands don't have a kick drummer, a snare drummer, a tom-ist(?) and a cymbal player in the band. They have a drummer. One person playing one instrument.

This is critical thinking in my experience. The most natural, and musical results capturing drum sounds that I have heard are those achieved by approaching the kit as a collective whole rather than a bunch of individual pieces. Here's why:

Having the ability to treat each component within a drum kit as a separate item (to be controlled individually) requires you to first isolate each item, otherwise you'll be treating the leakage as well. Drums are close together, along with loud, metal cymbals, and there simply isn't a microphone capable of picking up audio from one while ignoring the others. So the only way you'll get anything resembling isolation from component to component is to hard gate everything, which makes bleed from other components sound awfully strange as those gates open up and slam shut. Such gate 'chatter' quickly makes the drum sound awkward at best, and downright amateurish (or just BAD) at worst.

There will be bleed from mic to mic when recording or broadcasting a drum kit. Period. So unless you embrace this reality and use it to your advantage you may as well look into securing some blood pressure medication.... you'll be needing it.

Now let's start with the basic foundation of your drum sound.... the kick? Nope. The snare? Nope. I'm going with overheads.

Overheads?” you say? Yes, overheads. Not as obvious, or as sexy a choice as kick or snare, but if the kit is one instrument, what other mic other than an overhead hears the whole kit? Overheads are critical to the quality of your drum sound. 

[Yes, any room mics used will hear the whole kit as well, but they're farther away to capture ambience.  They're not part of the close-up 'kit' sound]
Here's the deal. While the drums on the kit will get there own mics, the cymbals generally don't. Overwhelmingly, cymbals are miked with a pair of condensers placed over the top of the kit, a few feet off the cymbals. The hi-hat will often get its own mic (which isn't always needed when mixing), and occasionally I'll stick a mic on the ride to give it more definition as needed, but the overheads are up high capturing the kit -- not just cymbals. The whole kit.

If this makes sense to you and you're okay with it you can pretty much skip the rest of this post. If this doesn't sit well with you, then you're likely from the “overheads are for cymbals only” school of thought, and your engineering will surely benefit from some additional explanation.

The frequency and harmonic content of cymbals goes down well into the low-mid range (these are 16” to 20” or greater diameter hunks of metal vibrating. Loudly). The only chance you have to isolate cymbals from the kit in any practical way is to drastically cut everything from the high mids on down (or, worse yet, boost everything above this range). When you do this you effectively cut the frequency range of the cymbals in half removing the punch and body that cymbals need in pop music. Bad idea. What drum is there whose frequency response you'd be willing to hack in half in the same fashion? Why, then, would it be acceptable to do this with cymbals?

Some engineers, when faced with this reality will opt to individually close-mic each and every cymbal, taking them from the proverbial frying pan and squarely into the fire. Now, not only do they now have increased leakage issues (more mics / more leakage) but they're now listening to the cymbals from a fundamentally unpleasant vantage point. When was the last time you listened to a cymbal with your ear right on it? That's not how we hear cymbals. They don't sound good up close -- they hum.


Yes, HUM. Remember, cymbal harmonics go down into the low-mid range. Take any cymbal, and 'crash' it with your finger and put your head near it as it decays. Hear that hum? Put a mic directly on a single cymbal and you will have a lot more of that to contend with than ever before. For every single cymbal. On. The. Kit.

If your solution to a problem is to create 2 new problems, is it really a solution?

Stay tuned...

Happy Tones!

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