Recording Drums
One Microphone
It is possible to get a surprisingly good sound using one microphone on a drum kit. When possible a condenser mic should be used as these capture the high frequencies of the cymbals a lot better than dynamic mics. The best way to get a good balance of each part of the kit is to put headphones on and move the mic around while the drummer is playing to find a sweet spot. Otherwise do some test recordings and move the mic depending on how these sound. I find a good area is about a metre in front of the kick drum, at about waist height, and pointing at the snare. If the mic is too close to the kit it will emphasise whatever part it is close to. If it is too far away a greater proportion of the room reverb will be present, leading to a distant sounding kit.
Using a few Microphones
If you are able to use three or four microphones it is best to put one on the kick drum, one on the snare, and use the others as overheads to get the rest of the kit. Depending on how many cymbals the drummer uses, the overheads may need to be a metre or more above the kit. If the mics are too close to a particular cymbal they will sound out of place in the mix. It may also sound ‘flappy’ if positioned at the same height as cymbals. This is because when a drummer hits a cymbal it rocks up and down on its stand. The cymbals produce very directional high frequency energy, the movement of cymbals means the energy incident at the microphone changes, causing the 'flappy' sound.
Invariably the kick and snare are the parts that need the most processing and mixing so it makes sense to have them recorded on their own tracks. Most cheap microphones will sound reasonable on snare and toms but are really not good at picking up the deep bass of the kick drum. There are specially designed mics for this purpose which provide a much fatter sound. If you already have a few mics in may be worth investing in one designed specifically for the kick. Full sets of drum mics are quite cheap now and these will come with a mic designed for kick drums.
Full Drum Kit Recordings
The standard way to record a full kit is dynamic mics on the kick, snare and toms with two overhead condensers over the cymbals.
The snare and tom mics should be positioned as close to the drum skin as possible without touching. This means you can achieve the best signal to noise ratio and separation between each drum. The resonances of the skins change between the outer and inner parts but it isn't really practical to put a mic anywhere but right at the edge of these drums. By experimenting with the angle of mics you can alter the sound due to these changes in tone. People often use a mic on the top and the bottom of a snare drum. By using the bottom mic it is possible to capture the metallic rattle of the snare. The top mic will have negative pressure when the drum is stuck, the bottom mic will have positive pressure. When these mics are mixed together there will be some phase cancellation due to the opposite waveforms. For this reason it’s best the phase reverse one of these mics. Phase reversal can be done on some mixers or with your audio software.
If the back skin of the kick drum has no hole, the kick mic should be placed as close as possible to the skin. The sound will change between the inner and outer parts of the skin so some experimentation should be done here. If the kick skin has a hole a mic can be placed inside the drum opposite the beater. Areas directly in front or near the beater sound have more high frequency energy than areas near the edge of the skin. This higher frequency ‘snap’ can sometimes give the kick more presense in the mix. Often kick mics are placed in the middle of the drum shell, or in the hole in the back skin. Like many things in recording this is down to personal preference, and what drums and microphones you are using.
Posted on Sun 6th Sep 2009 12:19:57
