From the February 2017 issue of DRUM! | By Karen Stackpole | Illustrations by Rick Eberly
Getting a great sounding drum recording in the studio begins with laying down good tracks, and that starts with the front end: the player and the kit, of course, and well-chosen microphones plied with good miking techniques. Sounds easy enough, right? But If you’re not up on your game with a working knowledge of sound physics and the tools of the trade, you can find yourself tripping over some common miking blunders that will prevent your recorded drum sound from ever reaching its full potential. With this in mind, let’s take a look at ten miking mistakes you should never make in the studio.
1. Having No Defined Sonic Goal At The Start
Entering into a session without a definite idea of the sound you’d like to achieve will set you back before you even begin. Knowing what you’re after enables you to work deductively backwards to arrive at the right tools and miking approaches for the job at hand. Do some preproduction to pave the way for a focused and cohesive sound that will make the back-end mix work more easily and deliver the results you’re after.
The first step is to evaluate the drum set acoustically in the recording space in context with playing dynamics and the style of music. This will help you to determine if the musical goal for the recorded drum sound would be better served by a more organic minimalist miking approach, a hardcore multi-mike setup for greater control in the mix to achieve a produced sound, or a moderate approach somewhere between the two extremes. The mikes you use and how you deploy your setup have a significant impact on the overall sound. Be prepared with a plan.
2. Making Uninformed Mike Choices
There are a lot of different kinds of mikes out there, each with its own distinctive sound quality inherent to its design, which will yield unique results on the source. Not being familiar with these characteristics and how to best match them to a certain instrument will limit what you can get out of your sound. Do your homework and know what makes a given mike appropriate for a specific application. Oftentimes more than one mike will fit the bill with different results, so experiment with a few options before settling for the right mike or mikes for the job.
To cite an example, the Shure SM57 is one of the most popular snare mikes out there because it has a respectable low-midrange response, great presence, and useful proximity effect that works well with a snare drum’s characteristics. But it doesn’t have a particularly airy sounding top end, whereas a condenser often does. So if you want crisper detail from the stick attack, use a small-diaphragm condenser in conjunction with the dynamic to better represent those highs and blend the two. Just make sure the capsules are aligned to negate phase issues. Which brings us to phase issues.
3. Disregarding Phase Relationships In Multi-Mike Setups
If your aim is to achieve greater surgical control in the mix by placing a multitude of mikes around the drum kit, you may find your sound is compromised if you don’t consider phase relationships. A phenomenon called comb filtering can happen when multiple transducers pick up a single sound source from different distances due to the time delays in the sound reaching the mikes. This also happens with reflected sounds. While each track may sound great soloed, when they are combined in context with the other mike channels, some frequencies will be cancelled out while others become reinforced, which leaves you with a weak, thin, hollow sound that no amount of EQ can remedy. (Fig. 1)
It’s essential to be familiar with the methods of mitigating phase issues. This includes reversing the polarity on one mike relative to the other, keeping microphone capsules equally aligned if double-miking the top head, choosing a coincident X/Y array for overheads, adhering to the 3:1 rule by placing mikes at least three times further apart from each other than they are from the sound source, and optimizing the off-axis rejection features of pickup patterns. Or simply reduce the number of mikes you’re using.
Explore distance adjustments and listen to the mike channels summed together to keep on top of phase problems. Filter-based phase adjusters, such as the Little Labs IBP, are available, and there are time alignment manipulations you can make on your DAW after the fact. But you may still find that the perfect snare/cymbal sound does not create great tom sounds, or vice versa. Optimize to the best compromise that fits the tune.
4. Forgetting That Sometimes Less Is More
While many contemporary recorded drum sounds require a close-miking approach, and while it can be fun to go all out, it can come at the price of the aforementioned phase issues. It’s good to keep in mind that sometimes less is more when it comes to miking drums. In some cases it can be helpful to be more minimalistic, and explore simpler setups, like using stereo miking arrays or 3- to 4-mike methods such as the Glyn Johns technique. While these approaches take away options for individual element control, they can be pivotal in creating a cohesive glue that brings the kit together as a whole. Often these techniques can be a great starting point from which to add other spot mikes, such as snare and kick. Discern whether the drum kit and the genre of music would be best served by these techniques through experimentation.
5. Ignoring The Effect Distance Has On Sound
Not being aware of the physics of sound coming off of an instrument and reflecting off the walls in relation to the distance at which you place your mikes can mean not capturing optimum results with room mikes and low frequencies. Critical distance is the location in the room where the reverberant reflected sound is greater than the direct sound. Room mikes should be placed beyond the critical distance for maximum effect to capture the ambience of the space. Any mikes placed before this location are essentially in the direct field and as such will have a more significant impact of introducing phase issues when added to the close mikes. Small, dead rooms often have limited options in this regard, so in those situations you may need to rely more on artificial reverberation added in mixing.
Distance also comes into play when it comes to low frequencies, which have a longer wavelength than higher frequency waveforms. It behooves you to let those wavelengths develop in the space before reaching the microphone if your aim is to accentuate that frequency range. One bass drum miking technique involves a large-diaphragm condenser in front of the kick drum to better capture an explosive low end. Let’s say you want to accentuate 100Hz from the bass drum. You can deduce the optimal distance at which to place the mike by taking the speed of sound (1,130 feet per second) and dividing it by the frequency (in this case 100Hz) — the ideal spot would be just over 11 feet in front of the source. (Fig. 2)
6. Not Using Microphone Polar Patterns Effectively
How a mike picks up and/or rejects sound is useful for controlling what gets captured in multi-mike setups, yet it’s easy to get sloppy when it comes to effectively employing polar pattern characteristics. For focus and rejection of juxtaposed sound sources in tight spaces, such as the hi-hat, snare, and mounted tom region, unidirectional mikes are best. A cardioid mike picks up sound from the front, rejects sound from the rear, and has less sensitivity to sound entering from the sides. But the physics of this results in coloration of off-axis sounds and makes it prone to proximity effect — a low frequency boost when placing the capsule close to a sound source — which is sometimes useful, and sometimes not so much. For greater rejection from the sides, hypercardioid mikes provide a tighter pickup pattern, but they have some sensitivity to sound directly behind the mike, so it’s important to consider this when miking toms with cymbals above and to angle the mike so that the rear lobe is not in direct line of fire from the cymbals.
Omnidirectional mikes pick up sound equally from all directions and often sound smoother with less coloration than unidirectional mikes, which make them excellent to use in a nice-sounding room with minimalistic miking approaches. Bidirectional mikes pick up sound from the front and the rear while offering superior rejection of sound from the sides. This makes them useful for capturing two sources or capturing direct and reflected sound while rejecting adjacent sound sources. Use the characteristics of a mike’s polar pickup pattern to your best advantage depending on the requirements for off-axis rejection, transparency, and frequency response. It’s also important to make sure the mikes will work well together as a whole.
7. Neglecting Microphone Filters To Control Sound
Some microphones commonly used for drums and cymbals incorporate an onboard filter often referred to as a “low-cut” or “high-pass” filter, or low frequency roll off, including the Sennheiser MD421 dynamic mike, the Shure SM81, and AKG’s C414, just to name a few. Not knowing when and how to use available filters on the front end is an oversight that can often mean more work on the back end, trying to clean up the sound so that each element occupies its own space in the mix without competing for the same frequency bands. For efficiency’s sake and a clearer-sounding recording right out of the gates, one would do well to take advantage of the onboard filters on various microphones to control the sound before it even gets to the mix stage.
Analyze the frequencies resonating and shimmering off of each element in the drum set. Do you need everything down to 60Hz? If not, get rid of it. A real bass drum isn’t going to produce anything usable below 60Hz, so rolling that off at the mike will make the end result easier to mix with the rest of the tracks. When miking cymbals and hi-hat, you will no doubt also pick up a lot of resonance of the toms. Utilizing a low frequency roll-off at the cymbal mike will instantly clean up a lot of that bleed so it won’t compete with the dedicated tom mikes. Judicious use of filters on the mikes in addition to low cut shelving on the mixing console can get rid of murk and mud without even needing to futz with EQ after the fact, provided your mike selection and placement are good to begin with.
8. Thinking Mikes Can Fix Everything
If the drums sound bad in the room, or if the tuning of the kit is off for the song, even the best mikes on the planet can’t repair those issues. The interaction between the source and the mike is the most important element that determines the final sound captured. This means starting with a great sounding instrument. Do some drum set maintenance and change the heads, do some tuning, take the tape off the cymbals, quell the squeaks and rattles, and make it sound good prior to the session. Give the mikes something to work with.
9. Not Adjusting The Microphone Angle
It may seem easier to rigidly emulate stock microphone placements and rely on processing later to fix any issues in the mix, but that’s definitely not the best route to take. Nothing beats using your ears and adjusting the position of the mikes to get the sound you’re after. Mike placement is the best means of shaping or “equalizing” the frequencies emanating from a sound source. Taking a few extra moments to optimize the position and angle of the mike, even minutely, or swapping out mikes for one better suited for the job, will yield far greater results than a processing fix. While there are some popular drum sounds that can be created only with aggressive additive processing, the path to the most accurate recording lies in capturing a great source with minimal phase issues, for less processing after the fact.
10. Miking Drums In The Studio As You Would Onstage
A live show stalwart who’s settled into a live sound miking approach as a matter of course risks missing out on the expansive options available in the more controlled environment of a recording studio. Onstage miking requires unidirectional dynamic mikes and padded condensers with tight pickup patterns along with judicious placement to maximize isolation and facilitate maximum gain before feedback. There are monitors to consider and stage spill, so close miking is the norm and area miking is a cautious endeavor at best. But the studio is less fraught with amplified perils, and you’ll often have bidirectional and omnidirectional mikes at your disposal in the form of dedicated and multipattern condensers and ribbon mikes, in addition to the unidirectional dynamic selections common in live sound reinforcement settings. Branch out and take advantage of the tools and the space to get the best recorded sound possible.