Drum Equalisation in Live Sound with Matt Keller
Drum equalisation in live sound
with matt keller
It is the job of the mixing engineer to make sure all instruments involved in a recording are appropriately discernible and that vocals are intelligible, both in the studio and in the live arena. This is no easy task considering you’re often dealing with multiple instruments all competing for the same areas of the frequency spectrum. Fortunately, we have several tools at our disposal to help us separate out the elements of the mix.
The two most common tools to help with separation are equalization and panning. Panning can be very useful to spread certain instruments (such as guitars, backing vocals or keys) to free up the center image for the likes of the snare and kick drums, bass guitar and lead vocals which are often best left in the middle. Positioning the instruments appropriately across the panoramic field can make the mix sound fuller while also helping the listener to hear individual instruments amongst the noise.
While studio recordings can take full advantage of the panoramic field, equalization is a vital tool for the Live Sound Engineer as mixes are often made with a much narrower stereo field. Because the left and right speakers are quite far apart, elements of the mix need to be reproduced in both speakers, otherwise the punters standing significantly closer to the left speaker will not hear sounds coming from the right, and vice versa. Although a wide mix may sound amazing from the sound desk in the centre of the room, this approach may be neglecting those listeners standing at the sides.
On approaching a live mix, ensuring the kick, snare, bass and lead vocals sit right together is a great place to start. These four elements sit bang in the centre of the panoramic field and are competing for similar frequencies. While instruments like guitars and keys can be panned a little to open up the centre image, panning the kick, snare, bass and lead vocals generally isn’t a good idea, so we need to apply the concept of ‘frequency stacking’ (giving each instrument its own space in the frequency spectrum to avoid masking) to achieve clarity in the mix using equalization.
In this article the focus will be on drum equalization. The drums are the driving force in the band, and play a large part in overall dynamics. The drum kit is also the only instrument (in most situations) that spans the entire audible frequency spectrum by itself, so having a great drum sound can really make a mix.
Having a good set of mics is a must for any Live Sound Engineer. Recently I’ve been using the new Audix DP7 drum and instrument microphone pack; it’s comprised of a versatile set of microphones that easily covers the bases. Their microphone clips are worth mentioning also; the ultra maneuverable design makes life alot easier (for both the engineer and the drummer) and keeping mic stands to a minimum frees the stage up for the musicians.
Below are some guidelines for EQing the main parts of a drum kit. These tips are a great place to start, however it’s important to remember to always use your ears!
Kick Drum (D6 Kick Drum Mic)
For most rock and pop applications we want to hear a kick with a solid thud and a nice round bottom end. It needs to punch in underneath the bass guitar, while also cutting through the mix with a bright click in the high mid range. To enhance the deep, impact sound, you can generally boost the Low Shelf filter by 2-3 db, or if you have a spare notch filter the 50Hz area is a good place to start. Scooping out the “mud” of the kick drum (normally between 200Hz-450Hz) can really clean up the sound of the drum and leave room for other elements of the mix, including the bass guitar and the lower fundamental frequencies of the guitars. Enhancing the “click” sound of the beater hitting the skin by boosting slightly in the 2k-6k range (sweep around to find the spot) helps the drum cut through in the mix.
Snare Drum (i5 Snare Drum Mic)
Along with the kick drum, the snare drum is essential for driving a rhythm track. Poor EQ can leave it sounding thin and dull, and can compromise the perception of the mix as a whole. In order to emphasise the best parts of the snare sound with EQ cut the low end by several dB at around 80Hz. Boost the body of the snare drum by 2-3db, usually around 200Hz. If you feel the snare needs more “bite”, boost a couple of dB at 2-5k. Finally, if extra brightness/air
is needed to open up the sound or you want to bring out the snare rattle sound, bump up the high shelf a little. Every snare is different, so start with these guidelines and play around until you’ve got it sounding just right.
Toms (D2 Rack Tom & D4 Floor Tom Mics)
Each tom has its own frequencies that should be cut/boosted to bring out its sweet-spots. Often it’s a good idea to start by using a noise gate to prevent the toms ringing out excessively, however if you’re short on gear a nice EQ job can certainly help tighten them up in a gate’s absence. For each tom the fundamental frequency will be different, so you’ll have to listen. If larger toms lack low end, boost the 80hz filter. Higher toms normally won’t need a low boost, so pulling down the low shelf a little can reduce spill from other instruments. You can also dip out the mud at around 500Hz to clean up the sound, and boosting high mids will enhance stick attack.
Overheads and Hi-Hat (ADX-51 Overhead Mics)
In many small venues it isn’t necessary to mic up the overheads as the highs from the cymbals will generally travel through the room on their own and amplifying that may simply be overkill. In larger venues you will likely need one or two O/H mics; if using two, ensure you place the mics in-phase with each other by creating a similar distance between each capsule and the centrepoint of the kit (usually the snare and kick drums). Applying the high-pass filter (which is usually fixed at 80Hz) will clean up any unnecessary subsonic rumble and cut out the thump of the kick drum. Dip out between
100-250Hz to prevent low-mid buildup. If the cymbals need extra top end sparkle, boost the high-shelf. Sometimes you may find there are ringing frequencies from the cymbals, in which case sweep with the parametric filter and notch it out.
As mentioned earlier, these are simply guides to get you going. Depending on the kit, type of heads on the drums, cymbal quality & style, and of course the environment you’re in, the sound can change drastically so the degree to which you need to affect each mic signal will change along with it. This is something that takes a lot of practice and as long as you’re always listening critically, your ears will develop with experience.
Matthew Keller is the Live Sound Workshop lecturer and Head Studio Supervisor at SAE Auckland (School of Audio Engineering). He is also a freelance Live Sound and Recording Engineer, having mixed bands in venues across the country from small pubs to 12,000 capacity arenas.
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