In a poll asking ‘For you, what’s the most difficult instrument to record?’ acoustic drums would probably be the absolute winner. A typical drum set includes a lot of different instruments, and both obtaining the right timbre in each of them and the correct balance between them all may feel like a complex and daunting task. If you are in this situation, this article is just for you.It will present some of the most used microphone techniques to record this instrument, along with audio files to listen to how each microphone type and position sounds.
The audio files were recorded at PKO Studios in Madrid. The recording session was organized in collaboration with Caco Refojo, PKO's Engineer and a Grammy winner for his work on Concha Buika's El Último Trago. And because a great drum sound starts always with a good drum set, well tuned, and played by a skilful musician, for the article we had the pleasure of counting on the experienced drummer Rober Aracil. With the team introduced, here we go.
The initial mic list was arranged with the objective of showing different drum recording methods simultaneously, and included close miking, techniques with one, two, three and four microphones, plus room and ambience mics. This initial list was later completed with Caco, to ensure PKO’s resources would be squeezed to the maximum. The final mic sheet included 30 microphones, which can be combined in different ways to listen to several techniques, but also to demonstrate the varying sounds obtained when changing microphone types, polar patterns and position: Dynamic, condenser and ribbon mics, using cardioid, hyper-cardioid, omnidirectional and 8-figure patterns, in mono and in XY, AB and Blumlein configurations were included.
Once the mic list was ready, the next step was to decide with Rober which drum set would be used, and the arrangement he would play. Because a good part of the techniques included room and ambience mics, we needed a ‘big’ set in order to excite the room with a good amount of energy.
The selected kit was a Rock Flow Custom model from the manufacturer Santa Fe, with a 24×20 kick, 14×8 snare, and 12×12, 16×16 and 18×16 toms. The drumheads came from Evans, and the cymbals were a combination of several Zildjian series.
Regarding the drum part, a song of the band Manaia (a personal project of Rober’s) was used. Different sections of the song were chosen and arranged, so the performance would show different common ways of playing the drums during a song:
The drum part starts with an intro with some tom hits, and then it is followed by a verse played in the hi-hat. After that, the pre-chorus enters using the ride to ‘open’ a bit the song, and the final drum part concludes with a big arrangement in toms for the chorus.
When we arrived at PKO, Caco had already placed all the mics in their respective stands, and the spontaneous comment of Rober ‘What a forest of mics!’ accurately defined the aspect of the room:
The recording room at PKO’s Studio 1 is about 90m2, with a roof at varying heights from 4 to 6 metres. The drum set was placed with a fair amount of space around it, but also in a way that allowed the placing of room mics at more than 5 metres away.
Because the objective of the article was to listen to the different nuances of each mic at its position, no additional processing was used in any channel. Only the SSL 9000J preamps were in the signal path, the filters were in the ‘Out’ position, and the EQ and dynamics sections were bypassed. Thus, the audio files show exactly what was being captured by each mic, with no additives.
When the drums were all set, and while the extensive microphone setup continued, Rober adjusted the tuning of the drums. Once all mics were connected to the SSL, the fun begun (although setting gains and checking phase relationships of so many mics isn’t exactly fun).
In order to follow a logical order in the description of the different microphone techniques, these have been divided taking into account the number of mics used. We’ll start with one-mic techniques, and then move to two, three and four-mic techniques, to conclude with the usual multi-mic technique so common nowadays.
Each microphone may be combined with the others in many ways, as we’ll see in the different sections of the article. Each audio file has a unique ID, so figures 1 and 2 may be consulted independently to check the details of each mic (model, type of transducer, polar pattern, etc.) and the exact position and distance to the instrument.
This is an approximate position of each mic in the room. For clarity’s sake, only room mics and OHs are shown (close mics are not shown). The image also contains mics present in the second part of the article:
If you want to capture the complete drum set with only one mic, it is vital that the instrument sounds good, that it is well tuned, and that the musician knows what he/she is doing (ok, these conditions always apply, but they are even more important the fewer microphones are used).
A good starting point with one-mic techniques is to place the mic centred over the kit (overhead). It is important to then listen to the balance of all the instruments in the different parts of the song, to check that it is correct in the different parts of the performance (playing in the hi-hat, ride, cymbals hits, etc.)
Starting with mic #1 (a Beyerdynamic M160 original), it was placed at about 120cm from the snare, and initially it was perpendicular to the floor. When listening to the sound that was being captured, the balance of the whole set was well compensated when Rober played in the hi-hat, but when he moved to the ride, this element sounded way louder than the rest of the elements.
So the mic was angled a little to the side of the snare, in order to aim the null of the polar pattern (the M160 is hyper-cardioid) to the side of the ride. This change also had the added benefit of better capturing the farthest tom (18 inches).
Microphone #2 (OH_RECORDERMAN) was a Neumann KM184, placed directly over the snare, about 80cm from it. This microphone is part of a three-mic technique (a variation of the classic Glynn Johns, more details in the second part). Although this mic is supposed to work with two other microphones, it allows us to check the differences in timbre captured in comparison with the mic #1 – it has a different kind of transducer and is closer to the snare.
Listening now to the second mic of the ‘Recorderman’ technique (mic #3, another KM184, at the same distance from the snare, but placed beneath the second tom), a new perspective of the whole set is discovered, in which the ride is logically louder than with mic #2.
In general, one particularity of the overhead mics is that, as they are placed over the kit, the sound of the kick is usually a little ‘thin’. Along with placing a second microphone in the kick drum (covered in the next section ‘Two mics’), another option to alleviate this is to place the single mic in front of the set.
There’s much more kick sound in comparison with the OH mics, and the timbre of the cymbals is again different. The result is a nice sound of the whole kit, a little warmer than the others (both because of the change in placement and the different type of mic).
Even when the mic #10 was not much farther from the set than the previous mics, there’s an evident increase in the room sound. This is due to the bi-directional pattern of the microphone: the rear lobe of the Nady RSM-2 was capturing the room sound.
A slightly different perspective is offered by mic #11 (FRONT_B). This is a small diaphragm condenser microphone (a DPA 4011), placed in front of the kit, but in a side of it. There’s a notable increase in the low frequencies of the kick drum, in part due to the change of mic, but also because the lower frequencies need more space to develop than the higher ones. For example, at a room temperature of 22ºC, the wavelength of a 43Hz sound wave is about 8m, and thus it presents maximum amplitude at 2m and 6m from the source.
Listening now to microphones placed further away, mic #13 (SALA_M_A) is a Beyerdynamic M160 (new model), placed 5m in front of the kit, about only 40cm from the floor.
The objectives of this mic were, on the one hand, to use the frequency response of the ribbon mic to capture the room sound, and on the other, to force a more aggressive response from the mic due to its closer position to one of the room limits (in this case the floor). There are always sound pressure maximums in the immediacies of the boundaries of a room, so placing a pressure gradient microphone on one of these points tends to force its response and behaviour.
For comparison, mic #14 SALA_M_B is an AKG C12, placed more than 6m away from the kit, and at a height of 3m. The response of the coveted condenser mic is shown in this audio file:
The differences with the previous mic are evident (not only due to their respective price, but also because of their different transducers and positions in the room). Using only one mic to record a complete drum set may seem strange nowadays, in part due to the drum sound it offers (any of the mics seen until now). However, if you’re looking for that kind of sound, go for it. Also, these mono mics are commonly used in combination with close microphones, to increase the depth and character of the instrument (details in the second part).
As mentioned earlier, some two-mic techniques usually combine one overhead mic with a second microphone in the kick drum, to reinforce the sound of this element.
If you are looking for a kick sound with a good attack, it is usual to place the mic inside the kick, using the hole in the resonant head (if it exists). Different positions inside the shell will provide different proportions between the attack and the lower frequencies of the instrument.
Mic #19 shows the sound of an AKG D112 placed inside the kick drum, 40cm away from the batter head and off-axis (oriented towards the beater)
Another usual place to put a mic is outside the bass drum, close to the resonant head (also off-axis). This tends to offer a fatter sound, with less attack than the previous position. Mic #20 is an AKG D12 (original) in that position:
This microphone offers a very different kick sound. If you, for example, choose mic #1 as overhead and combine it first with #19 and then with #20, you’ll see the resultant drum sound is quite different. This is a clear example of ‘microphone equalization’.
Something similar would happen if you choose one of the two kick mics, and then combine it with different overhead mics and room mics (#1, 2, 3, 10, 11, 12, 13 and 14). The drum sounds obtained are quite different, without having used any kind of processor.
Note: when more than one microphone is used to record the same instrument, it is vital to check how they ‘add’ when they are combined.This is usually known as ‘checking the phase’, and can be done quickly by flipping the polarity of one of the mics and listening to the sound obtained when combined with the other one. One of the positions usually offers a ‘fuller’ sound. However, in some inbetween cases changing the polarity doesn’t work 100%, and it is necessary to move one of the mics forward or backwards (physically), in order to achieve a good ‘combination’ of both microphones. The 3:1 rule is very useful to prevent phase problems, and it is as simple as this: each time an additional mic is used, the distance of this mic to the source should be at least three times that of the first microphone to the source.
This is not always possible (as in some spaced pairs we’ll see in the next article), but it is something important to have in mind when using more than one mic to record an instrument (any instrument). After this clarification, it was an objective for the article that all mics used would add constructively with the others, but due to the great amount of possible combinations, maybe you’ll have to flip the polarity of one mic when combined with certain other mics. And to conclude with the kick drum mics, another usual contender: a LCD mic, a little farther away from the resonant head. Mic #21 is a Neumann U47 Fet, placed about 25cm from the frontal head, on-axis. Due to this position, this mic tends to capture more ambience and cymbals than the other kick mics, so it is usual to see this mic covered with blankets, and/or to EQ it with a low-pass filter. In the section ‘Multi-microphone technique’ we’ll see how nowadays it is very common to use a couple of mics to obtain a ‘modern’ bass drum sound: one mic inside the shell to bring the attack, and another one outside to add weight.
THE SECOND INSTALLMENT
So far, we’ve had a look at some techniques with one and two mics, in mono. The second part contains stereo techniques with two and more mics, and the very common multi-mic recording setup.
I would like to thank to all the staff and management of PKO for their great work and hospitality.Special mention to Caco, not only for his superb work during the recording session, but also for his ideas during the preparation and planning of the article.Thanks also to Rober Aracil, for lending us his sound, equipment and expertise... but also for his patience, as the setup was longer than usual. 30 mics are a lot of mics.
* Rober uses Santa Fe drums, Evans heads and Zildjian cymbals.