In Part 1 of this article (available at www.churchproduction.com, Back Issues, May/June 2003), I discussed the philosophies of drum mic’ing, the pitfalls of drum mic’ing in live sound reinforcement, and a few other related issues. Here we will get into the more technical issues at hand and include some recommendations for specific microphones.
Microphone Choices and Characteristics
For live reinforcement of drums as well as most other sound sources,
directional microphones are almost always more appropriate than omnidirectional
microphones. There are a few very good reasons for this. First, the directional
pickup pattern provided by members of the cardioid or directional family of
microphones is a significant aid in reducing bleed from other instruments and
minimizing the pickup of off-axis sound such as reflections and reverberation.
Second, cardioid microphones exhibit proximity effect, a lowfrequency boost
that occurs when the mic is in close position to the source. For snare, toms,
and kick drums (as well as other drums in the percussion family) this inherent
characteristic is generally found to be sonically beneficial. Most cardioid
microphones also exhibit a presence peak in the upper mid range of 3-6 kHz,
and this is often useful for accentuating the attack of the drum hits.
Dynamic microphones are almost always preferred over condensers when mic’ing drums, and condenser microphones are almost always preferred over dynamic microphones when mic’ing cymbals. My experience is that dynamic mics are simply better suited sonically for drums, providing body and warmth where condensers do not. Another very important consideration is that dynamic microphones are physically more robust than condenser microphones (with a few exceptions) and therefore are better suited for placement in the “friendly fire” zone, where the drummer may actually whack the microphone from time to time. Drum microphones just seem to get abused more than any other mics on stage, and this is one of the considerations to take when selecting the microphones (not to mention when positioning them).
By far the most commonly used of the directional microphone family is the cardioid, providing fairly wide front-to-frontside pickup and significantly reduced sensitivity at the rear. Supercardioid and hypercardioid are two fairly common variations of the basic cardioid pattern, providing narrower pickup that results in increased “reach.” However, these also exhibit a rear lobe – or hot spot – that must be considered when positioning and aiming these microphones.
For cymbals, hi-hats, bells, and chimes, condenser microphones are most commonly employed in both sound reinforcement and recording environments. These provide smoother frequency response and superior transient (or impulse) response, which equates to improved high-frequency reproduction over that provided by dynamic microphones. They also typically cost more than their dynamic counterparts.
Omnidirectional microphones provide less coloration than the cardioid family of microphones because they are inherently flatter across their frequency range, they exhibit no proximity effect and they have no presence peak. However, as was pointed out in Part 1, we almost always need to employ directional microphones for live sound reinforcement because of the ever-present struggle to minimize leakage (from other instruments), to increase signal clarity, and to minimize the risk of feedback. Nowhere in live audio are the first two concerns greater than with reinforcement of the drum kit.
Incidentally, you are likely to find ample conflicting advice in various articles, texts, Internet forums, and advertisements relating to microphones. There may be good reasons to choose omnidirectional (over directional) and condenser (over dynamic) microphones for applications such as on-location and studio recording, broadcast production, and a few others. Almost anywhere that sound reinforcement is not the primary application we have much more freedom to choose microphones based solely on their sonic characteristics and without regard for the numerous and formidable obstacles that live sound reinforcement entails. My point is this: take such advice cautiously and consider your own application very carefully.
Large diaphragm condenser microphones are starting to become somewhat popular in the concert sound world for overhead drum microphone applications and sometimes for drums. Whereas these do provide some sonic improvement over standard (smaller) size condensers, they are quite large and weighty, and therefore require very careful stand and boom mounting so they do not tip over. I advise you to think very carefully before choosing to invest in this type of microphone for this application.
Placement and Stagecraft
As stated earlier, cardioid microphones exhibit proximity effect, and this
is often of benefit to many of the sound sources we reinforce. From the human
voice (especially male) to wind, brass, and stringed instruments, and throughout
the percussion family, the “free” bass boost that proximity effect
exhibits is often a useful element in achieving bottom or body (and to some
degree, power) from these instruments. How much proximity effect (and therefore
bass boost) you need is an artistic decision that each of us makes, and depending
on the specific tonal character (timbre) of the instrument we are reinforcing,
along with how this instrument interacts with the other sources we are mixing
to. This is no different than the choices we make when setting tone controls
and adding effects and during the mixing process. How do you vary proximity
effect? Easy: move the microphone. Moving it further away from the sound source
yields less bass boost and vice versa. Of course, you must pay attention to
how these adjustments affect the overall pickup of the intended source versus
adjacent and unintended sources.
Even the most well behaved drummer will eventually whack a microphone if it is placed too close to the center of action. This mandates a balance between our need to position the microphone close to the source but not close enough for the microphone to become the target. This also may influence your actual microphone choices. For example, although I prefer Sennheiser MD421’s for toms to most of the other microphones that I’ve tried over the years, I am very selective about where and with whom I use them. And I’m extremely careful about where I position them. I sometimes leave the 421’s (and my other favorite microphones) in the case and select cheaper and more robust drum microphones when they are to be used with younger and less disciplined players. Actually, there have been a few older drummers whom I don’t trust my good microphones with. In the case of the MD421, all it takes is one wellplaced hit to the capsule area to render this microphone unusable. And the repair costs are excessive.
Another common pitfall that can occur with boom-mounted microphones is that they can slip or droop from their set position due to cheap hardware and/or poor stagecraft. Spending good money up front on good stands and booms ensures that you will not blemish a service and end up with a back closet full of useless stands and parts. It is also time well spent to confirm that the clutch mechanism and various thumbscrews are tightened (once microphone placement is achieved) so that the microphone does not change its position during the service. Nothing sounds worse than a snare, tom, or hi-hat microphone that has moved and ends up laying on the drum head, rim or cymbal.
When boom-mounting microphones on stages and platforms, and for drum sets in particular, a tripod stand is by far more stable than a round-base stand. Place one of the three legs in between the drum and cymbal legs/stands so that the stand is tucked in as much as possible. Such care will result in neater appearance and a reduction in stage clutter and trip hazards. To further increase stand stability, use a short tripod stand (with or without a boom) for kick drum, floor tom(s), and the hi-hat. In Part 3, we will delve into signal processing and acoustical issues, and their role in sound reinforcement for drums.
Tom Young is a senior consultant in electroacoustics at Jaffe
Holden Acoustics (JHA) based in Norwalk, Connecticut. JHA specializes in both
architectural and electroacoustics for performance and worship spaces. For
more information, visit www.jhacoustics.com.
