A Primer On Choosing Recording Microphones

Miking

As any truck-loading, stick-wielding veteran knows, a drum kit is more than just an axe. It’s a complex creature composed of singular, closely arranged voices. This makes capturing the lot on tape (or hard disc, these days) a bit more challenging than simply finding and using that one favorite studio microphone. Mikes have as much individual attitude as you and your drum set. Choosing the best match for your particular vibe is an important part of achieving your recorded sound.

Of course, starting with a well-tuned drum kit and having your chops together is the main priority for any session, because you can’t hide when you’re under the aural microscope. If your kit is a pile, and you haven’t done your woodshedding, then it matters little if a vintage Neumann U47 FET is on your bass drum and a stereo pair of premium Schoeps is overhead. But if your kit is primed and you’re on top of your game, a bunch of Shure SM57s could do you justice. Of course, if you’re a slamming drummer, you could probably make a set of five-gallon buckets and cardboard boxes sound good under a bevy of Radioshack specials.

Miking

That said, whether you’re going into a big commercial studio or a smaller project studio, a little background knowledge of microphones can help you achieve the most important facet of any recording – a good drum sound. Of the many transducers available today, some are specifically designed to record drums, while other versatile models cover a variety of applications. A mike that works well on a kick drum won’t necessarily be the best choice for cymbals, and vice versa.

Variables that influence your microphone choices are the genre of music being played, the room ambience, isolation, your drumming style, and drum sound. Anywhere from two to over a dozen mikes can be used to represent your kit, and which ones and how many you use depends on the sound you’re going for, the number of tracks available, and the sound of the room. Microphone placement is also a factor, but that’s another subject that has addressed in past issues of DRUM! [see “Recording Tips” from Jan/Feb 1997 and “Onstage Percussion Miking Tips” from Mar/Apr 2001]. Instead we’ll describe basic types of mikes and look at which are appropriate for drum set applications.

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Meet The Mikes

Microphones can be broken down into three basic types: dynamic, condenser and ribbon. Nine out of ten times you’ll reach for dynamic and condenser mikes for your kit, but ribbon mikes can work in certain cases. Of dynamics and condensers, both large and small diaphragm versions are available. Generally speaking, larger diaphragm mikes tend to pick up lows well, while smaller diaphragm mikes exhibit better transient response due to lower mass, enabling them to clearly represent the leading edge of a sound.

Dynamic mikes are designed so that a coil attached to the diaphragm, moves through a magnetic field in proportion to sound vibrations affecting the membrane. This action induces an electrical current in the coil, creating the signal used by the audio gear. The mechanics of a dynamic make it durable and able to handle high SPLs (sound pressure levels), while limiting to a certain degree both its frequency and transient responses. You’ll find dynamic mikes in live sound reinforcement because they can handle the abuse, but they’re also a favorite for many drum-miking applications in the studio. Examples include the ubiquitous Shure SM57 and SM58, Sennheiser’s MD421, Electro-Voice’s RE20, and AKG’s D112.

Condensers, sometimes called capacitor microphones, operate on the principles of capacitance. A capacitor is comprised of two conductive plates separated by an insulating dielectric. In a capacitor microphone, the back plate must be charged, and therefore requires phantom power (tube condensers have their own separate power supplies). Voltage changes are caused by the movement of the conductive diaphragm against the charged back plate, in reaction to sound vibrations. This action translates into an electrical audio signal.

There are both large and small diaphragm versions of this type of mike. These mikes have an extended frequency response and a high sensitivity. They tend to be more expensive and not as durable as dynamics, and less able to handle high SPLs, but their response characteristics allow them to capture a higher degree of detail.

Ribbon (or velocity) mikes generate a signal through a crimped conductive ribbon suspended between two poles of a magnet. Most of these mikes have a bi-directional pickup pattern, although unidirectional models do exist. The element is typically delicate, although newer models are more robust. Ribbon mikes are not recommended for close miking drums, as the high SPL can damage the fragile ribbon. But these transducers have an excellent, warm high-end transient response, which can be an asset when choosing an overhead or room mike for a less bombastic situation.

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Secret Life Of Mikes

Another thing to bear in mind is how a mike picks up sound, which otherwise is called its polar pattern. A mike that picks up sound equally from all directions is omnidirectional. Cardioid mikes pick up sound from one direction only while rejecting sound from the rear and sides. Tighter unidirectional patterns are hyper- and supercardioid, which offer maximum rejection from juxtaposed sound sources if isolation is necessary. Mikes that pick up sound from the front and the rear while rejecting sound from the sides are known as bi-directional, or figure-8.

A mike’s frequency response often colors the sound being captured, and it is for these unique characteristics that mikes are selected. For instance, some mikes are designed with hyped high- and low-end response to best capture the desirable sonic attributes of a bass drum. Others have a sparkly high end that captures more definition, while others are extremely accurate with a razor flat frequency response. Where you place those mikes affects response. Placing a unidirectional mike close to a sound source will result in a low-end boost called “proximity effect,” a phenomenon you could use to your advantage. Let’s take a look at each instrument in the kit and examine tried-and-true microphone choices to set you off on the path to a great drum sound.

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Kicking It

If you’re looking for a chest-thumping classic rock or funk sound on your bass drum, start by looking at large diaphragm dynamic mikes designed specifically for bass drum. These mikes are essentially “pre-equalized” for the task at hand, with a slightly hyped high end for capturing a snappy attack, and fat, punchy lows for that big cajones sound. In this camp are the Shure Beta 52, Sennheiser E602, AKG D112, and Audio-Technica’s ATM25, just to name a few.

Smaller, jazzier kick drums may be better served by choosing a versatile large-diaphragm dynamic like Electro-Voice’s RE20, which has an airy low-end response shaped ideally for that jazz kick sound and isn’t as bright as an E602 or Beta 52. If you’d like a sound that is little less dark, you could try Sennheiser’s MD421, which offers some low mid punch without being overly aggressive.

For extra viscera-concussing woof, you could make your own mike with a 12" to 15" bass speaker by wiring it into a direct box. You’ll get plenty of lows around 50Hz and absolutely no attack. With a MD421 inside the kick pointed at the beater, and your homemade “mike” out in front, you’ll get a huge sound with a lot of chutzpah.

For a different sound, place a large-diaphragm condenser out in front of the kick rather than inside. This fancy option is especially useful for double-headed, smaller kick drums to get extended lows and a clearer attack. A drawback to using a condenser for a kick drum mike is that it is more sensitive than a dynamic, which makes it prone to leakage from other sound sources. Use your ears and judge whether or not the situation is appropriate for this approach.

Shure’s KSM32 has a fairly tight cardioid pattern, rejecting off-axis sounds adequately. When placed out in front of a small double-headed kick, it offers a warm, controlled low end, and a well-defined attack. Groove Tubes AM11 can capture tons of lows, while a Neumann M147 placed around four feet in front of the kick will give you plenty of punch and a classic, round tube-y sound. If you’re looking for a beefy bottom end with extra snap on the highs, a Neumann U47 FET is a good choice. For a brighter sound, try a Neumann TLM103. Experiment a bit with different mikes, but beware of overloading on high SPLs when using a condenser.

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Snaring The Perfect Snare Mike

What you’re looking for in a snare mike is a good transient response, wide dynamic range, and off-axis sound rejection to keep the hi-hat and other drums out of the picture as much as possible. No matter what style of music you play, most engineers will reach for a Shure SM57 to mike a snare. The SM57’s pronounced midrange response and high SPL handling capability make it perfect for the job. While it lacks somewhat in sensitivity, this trait is actually a benefit, and gives a snare that thick, warm recognizable sound without sacrificing attack. Other small-diaphragm, unidirectional dynamic mikes will also do the trick, from Electro-Voice’s conveniently swivel-mounted ND/408 and Shure’s Beta 58 to the Audix D1.

If you desire extra detail and tone, say for a jazz session, a sturdy small-diaphragm condenser can help with its greater sensitivity and wide frequency response. Examples include AKG’s 451, or Neumann’s KM184. Low profile miniature clip-on condensers such as Shure’s SM98 or AKG’s C418 also have excellent transient response, and capture extra detail and tone while being easy to place. I’ve found that the Oktava MK219 large-diaphragm condenser has a warm midrange and adds extra crispness to the snare sound.

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Tom Tom Club

Common choices for capturing toms are dynamic mikes like the Shure SM57 and Beta 56, Audix D2, and Sennheiser MD409, MD504 and E604. The MD504 and E604 have a response tailored for toms, and a slight brightness between 6kHz and 8kHz that accentuates attack. With tighter patterns, these mikes offer more off-axis rejection to help isolate each instrument. If you’re looking to capture bottom end, a large-diaphragm dynamic like Sennheiser’s MD421 has a darker, rounder-sounding response characteristic due to a slight low-mid boost.

For a more open jazz sound (assuming you’ve got the drum tuned that way) and to capture sticking detail or brushwork, a condenser will give you enhanced definition. A large diaphragm condenser like AKG’s C414 is bright, but does an excellent job of capturing the lows. With a switchable pickup pattern, you can opt for greater separation by selecting hypercardioid. Making use of proximity effect by placing the mikes in close can enhance the low end even more. AKG’s C3000B is also a good choice, capturing a big natural tom sound. The Shure KSM32, with its warm, controlled low-end response, would be an asset to a floor tom.

Small diaphragm condensers such as Neumann’s KM184 have an expansive, detailed sound and can represent a tight low end. They’re small and easy to keep out of the way. In a similar vein, miniature clip-on condensers such as Shure’s Beta 98 or Audio-Technica’s ATM35 give you that extra detail while keeping out of the way of stray stick strokes.

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Tipping The Hat

The overhead mikes usually capture the hi-hat quite efficiently, but for some styles of music, a hi-hat mike is warranted to enhance the stick work and foot action. A small diaphragm condenser is hands-down the best choice for this application because it captures crisp detail and usually exhibits excellent transient response. Examples include AKG’s C451 and 460, Neumann’s KM 84 and 184, Shure’s SM81, Audio-Technica’s AT4051 and AT4031, Audix’s SCX-one, and Crown’s CM700.

The CM700 is somewhat darker sounding, while the SM81 stays on the bright side of the spectrum. If you have crusty old hats that sound dull and clanky, you may want to toast them up with the SM81. If your hats are edgy, you may want to smooth the hackles with a CM700 or the smooth sounding KM184 or C451.

Aerial View

When it comes to overheads, condensers take the cake for their extended frequency response and sensitivity, and the sky’s the limit with the options available. Condensers that have a selectable attenuation pad are generally preferable because a drum kit can get pretty loud. If you want to mike primarily the cymbals while capturing the rest of the kit with close mikes, then small diaphragm condensers in a split overhead configuration may serve you best. If you want to capture a blend of the entire kit for a jazz recording, for instance, then you may want to go with either a single, broad-pattern mike, or with a coincident stereo pair of large-diaphragm condensers in an XY pattern. If you want a warmer sound, try some tube mikes.

An amazing sounding kit could benefit from representation by small-diaphragm omnidirectional microphones, which have a flat, extended frequency response and are very accurate. Because these mikes pick up sound from all sides, you’ll want to use them in a good sounding room that is isolated from other sound sources. Examples of these mikes include Earthworks TC30K or QTC1, Neumann’s KM183, and the B&K (now DPA) 4004.

For picking up a blend of the entire kit, versatile large diaphragm mikes with switchable patterns give you options. These include the Neumann U87, which is fairly bright with a smooth response, AKG’s C414, which has an excellent low end and is bright around 8kHz, making it good for picking up cymbal wash and definition on tom hits, and Audio-Technica’s AT4050. Other mikes that do well for this application are: the AKG C3000B, Blue Dragonfly, Shure KSM32, Neumann TLM103, and M49, just to name a few.

To capture cymbals, the Oktava MC012 offers good definition, and has a full, bright sound with warm lows. Other examples of small-diaphragm condensers that are popular as overhead mikes are AKG’s C451, Neumann’s KM184, Shure’s SM81 (which is fairly bright), and the Audix SCX-one. Vintage tube mikes such as the Schoeps M222 can give your cymbals some warmth without sacrificing detail.

In some circumstances, a carefully placed, more robust model of ribbon mike could be appropriate if you have a good sounding room and you’re looking for excellent transient response and a smooth, soft high end without the sizzle-y characteristic of condensers. The pickup pattern of most ribbon mikes is bi-directional (a.k.a. figure 8), so both source and reflected sounds will be picked up from the front and back of the mike, but not from the sides. Royer’s R121 or SF12 stereo mikes are well-suited for this application, as is the British-made Coles 4038, which Ringo has used as an overhead.

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A Room Of One’s Own

A single mike can capture the room sound, or a stereo array can be used for a more expansive and versatile sound. High-end large diaphragm condensers, tube or otherwise, are often favored for this application, such as a Neumann U87, or U67 tube mike, or a TLM103 for more focused punch. AKG’s C12 is also popular, and a C414 would give you some exaggerated brightness if you were looking for more definition. For stereo miking, AKG’s C24 and Neumann’s SM69 stereo tube mikes are excellent. If there’s one on hand, a Calrec sound field mike with its polyhedron capsule array will give you plenty of mix options. PZMs are also an interesting way to get a room sound without worrying about phase cancellation issues. Crown makes some popular models, and MBHO makes the C622 for drums, a unique OSS-style stereo PZM based on the Jecklin disk design.

In The End, You’ve Got Sound

To summarize, there are many different mikes available, and the ones you choose to mike your drums for a recording session depends on your kit and the sound and vibe you want to achieve. It’s up to the engineer, and to you. A little savvy can give you a starting point from which to shape your sound with microphones. Save yourself extra work at mix down by tuning your drums up right, practicing your ass off, and picking the mikes that will best represent your sound. There is no “one way” to mike a kit. Hopefully this diatribe has given you a starting place from which to launch your exploration into the world of microphones to capture your own special drum sound.