Photo by Josh Sorenson on Unsplash
Vocals are the crown jewel in a song or musical production. Among musical instruments in a band though, drums are the ones that take that important front spot. I have heard many prominent sound engineers say that, generally speaking, if you get a nice drum sound, the whole mix will be easier to construct. Drums don’t have to be loud to sound good—all they need is to have the correct set of mic’ing techniques, dynamics, EQ, some effects and other related factors to produce a great sound.
The Drum Sound
It’s important to start by describing the nature of the sound under discussion. Drum sounds are like pulses or small explosions of sound (high pressure wave fronts). These have a very fast leading edge (i.e., transient) and very short lived that can last between 10-15 milliseconds (ms). This is when the stick’s tip hits the drumhead. This tiny section of the sound wave contains the medium-high and high frequencies. After this initial pulse, the vibration propagates to the rest of the drum cylinder and to the bottom drumhead, creating a resonant sound. This section of the wave contains the low mids and low frequencies and can last up to well beyond one second. As you can see (or hear), a drum set has a wide frequency range, however, it is limited or localized to certain zones of the spectrum. In addition, there are cymbals that produce sounds with very high frequencies (3k to 10k).
What makes a good drum mic is how it responds to the fast transients of sound pulses. The quicker it responds to the initial edge of the sound wave, the punchier and clearer the reproduced sound will be.
Mic Selection
There are many options here, but low-budget mics, in my experience, are often not worth the effort. At the other end of the spectrum are high-end mics, with price tags starting at around $250 and going all the way up to thousands of dollars. Many of these are not affordable for churches. And in this price range, you had better have a very high-end drum set, because these mics will pick up the slightest nuances of your drums and drumheads.Medium budget drum mics run in the range of $90-$200 each. What makes a good drum mic is how it responds to the fast transients of sound pulses. The quicker it responds to the initial edge of the sound wave, the punchier and clearer the reproduced sound will be. Medium budget drum mics usually have a transient response that is fast enough to produce a nice punchy sound. A final feature to note is frequency response: the lower it goes the better it picks up the “bassy” low-end frequencies. A 60 Hz-16,000 Hz frequency range is good enough for most drum applications. Some mics have a natural boost or peak around 5 kHz, which helps in giving definition and crispness to the sound (always review the frequency response graph of your mics and of any prospective purchases). As in the recording studio, the less EQ you have to use, the better and more natural sound you will get.
Mic Placement
Much as in real estate, location is critical; it plays a huge role in the sound you will get through your mics. If the mic is not placed correctly or with the correct orientation, the sound it will pick up will suffer. Consequently, you will end up trying to fix a sound using too much EQ or dynamics and, in most cases, it will end up sounding bad no matter what you do at the console. Remember the old adage: “garbage in, garbage out.” Mics do not perform miracles; they will transmit what they “hear.” The rules for mic placement and orientation are very simple and straightforward: around two or three inches above the rim, pointing to the center of the head. The height and angle help by allowing the diaphragm to pick up more attack, while also picking up the low end. Pointing the mic to the center maximizes the capture of the high frequencies.Another point to note: the environment of a drum set is very violent, so make sure you tightly affix the mics so they don’t shift position during a performance.
Dynamics
After placing your drum mics, set the preamp gain to an appropriate workable level, leaving room for the additional gain that may come from EQ or from the compressor’s output stage. I find it easier and quicker to begin setting up the dynamics before working with the EQ. I also find it more convenient to dial some basic settings in the gate and compressor, then do the same with the EQ, and then come back to fine-tune the dynamics. Generally speaking, when using gates in drums what you are trying to do is to minimize the bleed of one of the drums through other mics in the set (i.e., to keep all mics closed and only open the one that really has to be active). This can help enormously in getting a cleaner drum sound. So the idea is to set the gate’s threshold to a level that will keep this particular mic closed (e.g., Tom 1) when other drums are hit, but, at the same time this level should allow the gate to activate when this particular tom is played.
The compressor threshold is easier to set. Once you set the attack, ratio and release, start to decrease the threshold until you get between 3 dB-6 dB of gain reduction. Then set the output gain to level back what is being taken away (between 3 dB-6 dB of output gain). Many people forget to set the output gain and without this you are only half-way finished. EQIn a well-tuned drum set with its drumheads in good condition, my experience is that the generally used basic drum EQ works quite well as a starting point. All I put in is a filter around 300 Hz, -5 dB to -8 dB reduction, and play with the bandwidth until I get a nice low end. The purpose of this filter is to enrich lower frequencies by reducing higher resonant frequencies around this zone (300 Hz-400 Hz). This has the effect of “boosting” lower frequencies without having to increase them manually (this is a psycho-acoustical phenomena).
Some mics have a natural boost or peak around 5 kHz, which helps in giving definition and crispness to the sound (always review the frequency response graph of your mics and of any prospective purchases).
Finally, I accentuate a little bit (3 dB approximately) frequencies around 3k-5k for definition. Too much boost in this range could cause your cymbals to bleed excessively through the toms mics. As with any other parameter mentioned here, fine-tune them until you hear what you are looking for.The kick and snare are special cases. You can get fairly good results using one mic on each. However, using two mics for each brings several advantages, such as more presence without having to increase the gain, more EQ freedom, and more punch (as long as they are set up correctly). Be aware that mic’ing the same source with two mics adds another layer of complexity, since now you have to consider phase and/or time alignment.
On the snare, the bottom mic is used to pick up the details of lighter playing techniques (like when using brushes, rebound strokes, multiple bounce rolls, etc.) while also reinforcing the high frequencies. The gate settings for the bottom mic are more relaxed; the threshold activates at a much lower level than the top one. When using two mics on the kick drum one goes inside (usually a condenser such as the Shure beta 91A) and the other is placed outside right at the drumhead opening, in the opposite kick drumhead pointing to the kick mallet. I use the same gate and compressor settings for both, adjusting the threshold for each individually. The EQ is similar to the one used for toms, but, in the kick you may want to boost 3 dB-5 dB with a narrow Q the low frequency where your subs are more efficient (between 40 Hz-60 Hz). Make sure to put this low frequency boost only in one of the two mics, not in both (to protect your sub woofers). Now you need to align the two mics in the snare as well as the two used in the kick. The process is the same for snare and kick.
The ideal way to align is by delaying in time the response of the first mic (the one closer to the point of impact). The amount of delay is approximately the difference in distance from the point of impact to the first (A) mic and from the point of impact to the second mic (B), (B - A = delay). The problem is that not many digital consoles have a time delay setting in each individual channel—only some high-end consoles do. Alternately, you can use the polarity reverse switch (some consoles name it “phase reverse”) to reverse the polarity of the signal for the second mic. Judge which polarity works best by using your ears and deciding in which mic it sounds better (the first or the second).
FXs
Effects (FXs) complete the icing on the take for a great drum sound. These also may help a lot when the drum set and mic combination is far from what we dream of. FXs in drums are used to give ambient (when using a too dry-sounding enclosure) and/or as a special FX to provide extended reverb. The standard FX used in drums is a plate reverb with a high frequency roll off starting around 5 kHz. A hi-pass filter at around 250 prevents muddiness in the FX sound. The delay can be set between 300 ms up to 2.6 seconds depending on the performance and taste. In some cases you can also play with the pre-delay to accent the FX (20 ms-70 ms).
Drum Enclosures
Drum enclosures are a huge help in small- and medium-sized venues for controlling the direct sound from the drums hitting too hard into the audience, and/or preventing the drums bleeding into the singers and other mics (and in controlling out-of-control drummers). But they can also kill your drum sounds if they are not designed correctly. Drum enclosures should not have parallel walls, and if they do, one of the two should be covered with the proper sound-absorbent material. When a full enclosure is not possible or practical, an acrylic shield in front or around the drums provides good results, too.
