If we surveyed all ISP readers asking "which instrument do you find hardest to record?", the acoustic drum kit would probably emerge as the undisputed winner. A typical kit involves a large number of elements, and getting both the desired tone from each of them and the right balance among them all can seem very complex.
The magazine's editorial team regularly receives questions about miking techniques for capturing this instrument, which one is best in different situations, types of mic, etc. That's why we have prepared a series of articles that will illustrate, from both theoretical and practical points of view, the different ways of approaching the recording of this instrument.
This article takes a practical tour of the most common miking techniques, since we have also prepared samples from 30 different microphones (ready to download), recorded in a luxurious environment: PKO studios. In collaboration with Caco Refojo, a PKO engineer (and winner of, among other awards, a Grammy for his work on Concha Buika's album El último trago), we organized the recording of the same drum kit using several methods... the final setup included more than 30 mics! Plus an impressive Solid State Logic 9000J, the exceptional room of Studio 1 and some legendary mics...
And since a great drum sound always starts with a good drum kit, properly tuned and played by a good drummer, on this occasion we had the pleasure of working with a musician with a long professional career: Rober Aracil (Pereza, Buenas Noches Rose).
With the team introduced, let's begin. You can download the audio files for this first installment at www.ispmusica.com.
The preparations
The mic list was prepared with the aim of illustrating multiple methods for recording an acoustic drum kit, and it included both close miking and techniques with one mic, two mics, three mics, ambient mics, room mics, etc.
The initial channel list was finalized with Caco to make sure PKO's resources were used to the fullest (ISP's October 2010 issue has a detailed feature on the studio). The end result included 30 microphones which, grouped in different ways, let you hear several techniques firsthand, as well as the differences obtained by changing the type of mic, polar pattern and position: dynamic, condenser and ribbon mics, in cardioid, omnidirectional, figure-eight patterns, etc., using XY, AB, Blumlein techniques...
With the setup ready, the next step was to decide with Rober which kit would be used and the pattern to be played. Since a good number of the techniques would include ambient and room mics, we chose a large-sized kit that would excite the room with plenty of energy. The kit used was a Santa Fe Rock Flow custom, with a 24x20 bass drum, a 14x8 snare and 12x12, 16x16 and 18x16 toms. The heads are by Evans, and the cymbals come from various Zildjian series.
As for the pattern, one of the requirements was that the recording be around 30 to 40 seconds long, so that downloading the files afterward wouldn't be too heavy for users with slower connections.
With this in mind, we chose a song by Manaia (Rober's personal project) and selected different sections to put together a performance that would allow the drums to be played in the most common ways: the pattern starts with an intro featuring tom fills, then moves to a verse on the hi-hat. Next comes a pre-chorus on the ride that opens up the song, finally concluding with a chorus built on a big tom-based pattern.
The aim was for the performance to make the wood resonate properly, so as to hear firsthand how the instrument interacts with the different mics.
The setup
When we arrived at PKO, Caco already had each mic on its respective stand, and Rober's spontaneous comment described the look of the room perfectly: "What a forest of mics!"
Room 1 measures approximately 90 m2 (about 970 sq ft), with a ceiling height ranging between 4 and 6 m. The drum kit was set up so that there was a large space around it, while also allowing room mics to be placed more than five meters away.
Since the ultimate goal of the recording was to evaluate how each mic behaved in its position, nothing but the SSL 9000J preamps was used in the signal chain. Each mic was connected to its own channel on the Solid State Logic, and the filter, EQ and dynamics sections were disabled on each. What you hear in the audio files is what the mic captured, with no additives.
Once the kit was set up, and while the extensive mic setup continued, Rober personally took care of adjusting the drums' tuning to the room. It's common for head tension to shift slightly due to the vibrations and temperature changes involved in transport. Once all the mics were connected to the console, they were placed around the kit for an initial gain check so we could start setting levels and checking the phase between the different mics.
Miking techniques
To follow a logical order in describing the miking techniques used, they have been divided according to the number of mics they use, starting with single-mic techniques, then moving on to two mics in mono, two mics in stereo, three mics, four mics and, finally, multi-mic recording.
Each microphone can be combined with the others in different ways, as explained in each section. In addition, each audio file corresponds to a single mic and has a unique identifier, so figures 1 and 2 can be consulted independently to check details about the type of microphone (brand, model, transducer type, polar pattern, etc.) as well as its position and distance from the instrument.
One mic
When it comes to capturing the whole kit with a single mic, it's essential that the drums sound good, are properly tuned and that the musician knows what he's doing (granted, these premises always apply, but the fewer mics you use, the more important they become).
A good starting point is usually to place the mic above the kit (overhead), centered. It's essential to listen to the balance of the instruments over different passages to check how the kit sounds at different points in the performance (playing on the hi-hat, ride, cymbals, etc.).
Mic #1 (an original Beyerdynamic M160) was placed at a height of approximately 120 cm above the snare and was initially pointed perpendicular to the floor. Listening revealed that when Rober moved to the ride, it sounded louder in the mic than the rest of the kit, so we tilted the microphone slightly toward the snare so that one of the M160's less sensitive sides (the mic is hypercardioid) faced the ride more directly. The change also allowed the farthest tom (the 18") to be picked up better. The result can be heard in the OH_MONO file, which has a very well-balanced sound across the whole kit.
The particular characteristics of the ribbon mic mean that the cymbals' brightness is different from what it would have been with a condenser mic, as is the case with the next microphone: the OH_RECORDERMAN track corresponds to mic #2, a Neumann KM184 placed above the snare at a distance of about 80 cm. This microphone is part of a three-mic technique, a variation on the classic Glyn Johns technique (details in the next issue). It is meant to work together with two other mics but, in any case, it lets you hear the difference made by being closer to the snare than #1, and the variation in captured tone compared with the ribbon mic.
If you listen to the second mic of the "Recorderman" technique (#3, another KM184, at the same distance from the snare but positioned from behind tom 2), you get a new perspective on the kit, in which, logically, the ride is more prominent than in the previous case. You can also hear that, since it isn't positioned directly over the cymbals, their tone changes.
One particular trait of overhead mics is that, being placed above the kit, they can be slightly lacking in bass drum. Besides the possibility of adding a second mic on this element (see the Two Mics section), another option is to place the mic in front of the kit.
The FRONTA_A track (corresponding to microphone #10) lets you hear the result of placing a ribbon mic in front of the kit, at a distance of about 170 cm and a height of 160 cm.
You can hear that a lot of bass drum has been gained compared with the OH mics, and that the character of the cymbals is also different. The result is a nice kit sound, somewhat warmer (not only because of the change in position but also because of the type of mic). Although it isn't much farther away than the previous ones, you can clearly hear an increase in room sound, because the microphone had a bidirectional pattern.
A slightly different perspective is offered by #11 (FRONT_B), since it is a small-diaphragm condenser mic (DPA 4011) positioned to the side of the kit. In this case, a bit more of the snare wires is captured, because their sound isn't masked by the bass drum (compared with #10). In addition, the snare and bass drum are slightly better balanced.
And yet another perspective can be heard on #12 (a Manley Gold Stereo using only the mono capsule), since it is a large-diaphragm condenser placed somewhat farther from the kit than the previous two.
The increase in the bass drum's low frequencies is worth noting, partly due to the change of mic, but also because we mustn't forget that lower frequencies need more distance than higher ones to develop.
Moving on to even more distant mics, #13 (SALA_M_A) is a Beyerdynamic M160 (new model), placed about 5 m from the kit (facing it), at a height of just 40 cm off the floor. With this microphone we were looking, on the one hand, for the ribbon mic's frequency response to capture the room and, on the other, for a position close to one of the room's boundaries (in this case the floor) that would produce a more aggressive response from the microphone. Since there are always pressure maxima near the boundaries of a room, placing a pressure-gradient mic there logically affects how the mic behaves.
For comparison, #14 is a legendary AKG C12, placed almost 6 m from the kit and raised about 3 m off the floor. The condenser mic's response can be heard on the SALA_M_B track, and the differences from the previous one are obvious (and they aren't due only to the price of each).
Using just one mic may seem somewhat odd today because of the drum sound it produces (any of the ones we've seen so far), so these mics are generally used in combination with close miking (details in the next installment).
Two mics
As noted above, some two-mic techniques often involve using an overhead mic in combination with another on the bass drum to reinforce the sound of that component. If you want to capture a sound with attack, the mic is usually placed inside the bass drum itself, or in the port of the resonant head (if there is one). The different positions provide variations in the balance between the instrument's lowest frequencies and its attack.
Mic #19 shows the sound of an AKG D112 placed inside the bass drum, about 40 cm from the batter head and off-axis, pointed toward the beater. Another common position is outside the bass drum, right against the resonant head (also off-axis). This usually produces a fatter sound with less attack than the previous case: mic #20 is an (original) AKG D12 (in image 5, it is on the left).
If you choose, for example, mic #1 as the overhead and then combine it, alternating between #19 and #20, you can easily hear the variation produced in the final bass drum sound. A clear example of EQ through mic choice. The same would happen if you chose one bass drum mic and alternated between the different OH and room mics (mics 1, 2, 3, 10, 11, 12, 13 and 14); the final drum sound changes considerably, without even touching a single processor. A note at this point: when more than one mic is used to capture the same source, it's essential to check how the mics "sum" when combined. This is usually known as "checking the phase," and it can be done quickly by flipping the polarity of one of the mics and listening to the result, choosing the setting (polarity inverted or not) in which they sum best. In some in-between cases, just changing the polarity doesn't work 100%, and one of the microphones has to be moved forward or backward to get them to sum as desired.
The 3:1 rule is very useful for preventing phase problems, and it's as simple as this: every time an additional mic is placed, make sure that the distance from this new mic to the source is at least three times the distance from the initial mic to the source. This isn't always possible (for example, in some spaced pairs we'll see later), but it's always worth keeping in mind whenever more than one mic is used, whatever instrument you're recording. With that clarified, we should point out that we tried to make all the mics in this article sum constructively but, given the large number of possible combinations, you may need to change the polarity of some depending on the combination you choose.
To wrap up the bass drum mics, we've also included another frequently used element: a large-diaphragm condenser mic placed some distance from the front head. This is microphone #21, a Neumann U47 FET positioned about 25 cm from the resonant head, centered on-axis. Because of its position, this mic picks up more cymbal and snare ambience than the previous ones, which is why it's common to see it covered with a thick blanket or EQ'd with a low-pass filter. As we'll see in the multi-mic section, it's very common to use two mics to get a "modern" bass drum sound: one inside to capture the attack and another outside to add body.
Coming up
So far, a tour of some one- and two-mic techniques (in mono). The next article will cover stereo techniques with two, three and four mics, as well as today's common multi-mic recording approach and the use of other (stereo) room mics.
If you've read this far but haven't done so with the audio files at hand, we recommend downloading them from the ISP website and following the text with the audio examples loaded into your usual DAW. Take the time to listen to each track separately, from start to finish. Listen to how the mic sounds, try to imagine where it was placed, analyze what each one conveys to you, and compare all this with the different types of mic, distance, etc. Each track contains a lot of information.
Without getting too far ahead into the next techniques, try choosing one of the OHs, adding the inside and outside bass drum mics to taste, and completing the picture with one of the room mics. There are many colors available just by changing mics and positions.
NOTE: at the beginning of each file there is a click that was added artificially after recording. It is at exactly the same point in time on all tracks, so it lets you align all the files precisely if in doubt.
*Photography: Pitu López