Making The Most Of...
Some people look upon the prospect of recording an acoustic drum kit with dread. It needn't be that daunting if you follow a few simple guidelines.
Acoustic drum kits are notoriously inconsistent when it comes to sounding their best in the studio. There are few set rules in recording but the following guidelines might get you off to a good start.
The secret of a good drum sound is in fact a combination of several different aspects, most of which I hope to cover during the course of this article. In order to get the best out of the equipment available, the drums must be carefully tuned, properly played, and the right type of microphones placed in the best possible places.
Though a drum kit should ideally be considered as a whole single instrument rather than as a cluster of individual drums and cymbals, it's often necessary to examine each drum in turn before listening to the kit as a whole. Because the bass drum frequently causes the most problems, I'll jump in at the deep end and start there.
It's possible to get a good sound out of a double headed bass drum, but for close miking, which is what I'll explore first, it's common practice to use a bass drum with a hole cut in the front head. Some engineers advocate removing the front head altogether but the drum manufacturers advise us that this practice causes undue stress in the shell which can lead to a degradation in tone or even to shell distortion. From an engineers viewpoint, it's better to use a head with a large cut-out as this keeps the front tensioners tight and prevents the nut boxes rattling; a problem frequently encountered when tensioners are removed. In the past I've had problems with front heads that had only small holes cut in them, as the remaining head material resonates in sympathy with the drum, giving a blurred sound. The only way round this is to damp the remaining part of the front head with pads of cloth or tissue held in place by Gaffa tape. This is easy enough to do providing that you are aware of the problem to start with.
Damping is another important area and it is generally accepted that the dampers fitted inside drums are best left alone and other methods employed. A heavy blanket placed in the bottom of the drum is still the firm favourite but you can use pillows (feather, not polyester) or even heavy sleeping bags at a pinch. The drum may then be tuned to the required pitch but the story doesn't end here, there's the beater to consider. If the currently popular slappy sound is what you're after, it's no good using a soft felt beater, you'll need a wood or leather one, and if that still doesn't give you the attack you're after, other tricks include sticking a mole skin patch, a beer mat or even a coin onto the head at the point where the beater strikes.
There are almost as many favourite microphones as there are sound engineers, but for use with bass drums, there are definite popular models. The AKG D12 is one of the first to spring to mind, as it's capable of handling the extreme sound pressure levels experienced in the close vicinity of a bass drum head and it also has a peak in its response at around 80Hz that gives it a lot of bottom end punch. Some engineers however consider that the D12 gives a rather dull sound by modern standards and is not entirely suitable if you want a really 'slappy' drum sound. Other models that are often used include the Electrovoice RV20, the AKG 202 and the Sennheiser MD421 but this list is by no means exhaustive, which is just as well because a lot of home users have to make do with far less expensive mics.
"...this practice causes undue stress in the shell which can lead to a degradation in tone or even to shell distortion."
Good results can be obtained with the Shure PE65 or the Shure SM57, and it is worth trying any dynamic mics that you may have to see what sort of result they give. Don't expect too much from really cheap mics, however, as they are likely to flinch at the sound pressures involved and tend to have a poor bass response.
Having decided on the best mic for the job, positioning is also very important and the best results generally involve mounting the mic on a boom positioned inside the drum with the mic directed towards the point of impact and distanced some six to twelve inches from the head. Using this as a starting point, you can sometimes effect further improvements by moving the mic slightly off centre or not pointing it directly at the beater. It's not a good idea to rest the mic on the damping blanket as you will inevitably upset its directional characteristics and in any event, a stand gives you more control over the mic position.
If the sound records well at this point, all well and good, but if you have a lower mid control on your mixing desk, you can cut this to a greater or lesser extent to minimise 'woolly' overtones. Another useful dodge is to patch a psychoacoustic enhancer such as an Aphex Exciter or one of the excellent Tantek modules into the channel insert point. By tweaking the controls, you can get a modern slappy sound of surprising quality out of the most dubious bass drum. This tactic also applies to the snare drum and helps you to achieve a snappy snare sound from even a dull sounding drum.
If however, at this point the bass drum still sounds like a hot water bottle full of porridge, you could consider taping a transducer onto the head and use this to trigger a digital drum sound such as the E&MM Syndrom module or a Ted Digisound box.
Lastly, if you have a spare noise gate that you can use on the bass drum channel insert point, set it up with a fast attack time and a fairly fast release time to cut out any residual ringing and to improve separation. This also has the advantage of shutting out any pedal squeaks. Don't forget, though, to make sure that the gate is not cutting off any of the quieter beats before you go for a take.
"...the remaining head material resonates in sympathy with the drum."
If that seems like something of an epic procedure, don't forget that we've only covered one drum so far and we've still got to sort out the rest of the kit.
After the bass drum, the snare usually gives the most trouble. After all, this antiquated throwback from the military band era was never designed to play alongside the bass guitar or even be miked up for that matter. Apart from being notoriously difficult to tune, this wretched device takes delight in rattling and buzzing in the presence of any sound source not of its own making.
Don't despair, just get the thing tuned up properly, make sure that the heads are in good condition and throw away the internal damper. Snare tension is very important as any proficient drummer will affirm, and the correct tension will give a crisp sizzle; too slack and the drum will rattle - too tight and the snare sound will change from a buzz to a choked zonk. Check the tone by damping the batter head (the one you batter) with the palm of your hand and when you are satisfied, tape on a pad of folded kitchen roll or cloth about three inches square with Gaffa tape. This should be positioned so that the drummer is unlikely to hit it, and it should not be placed directly under the microphone.
Resist the temptation to tape over the snares to prevent rattling as this will just destroy the sound. One dodge is to tape a coin onto the underside of the snare head which has the effect of pulling the head down onto the snare, but whatever method you go for, do check that the snare itself has no loose strands; any such should be promptly removed using wire cutters.
Draping a heavy blanket over the top of the bass drum sometimes helps to cut down rattles and improves separation. As an added bonus, this will absorb some of the sound from the bottom of single headed bass drum mounted toms; another potential source of snare rattle. Likewise, there is a considerable difference in sound between a kit set up on carpet and the same kit on a hard, bare floor.
"If you want to end up with a kit that sounds like a suitcase full of Swarfega, save yourself the expense of a drum kit and use the real thing."
The demands on the snare drum mic are not so stringent as those pertaining to bass drum mics, and Shure SM57s are very popular for this purpose as are Unidyne IIIs at the budget end of the market, and for home use, most decent dynamic mics can be coaxed into giving satisfactory results. Even the very cheap Shure 517 sounds acceptably good on snare though it is pretty useless for bass drum or toms.
Positioning the mic is of course important, the first priority being that the drummer must not hit it. I generally start off by placing the mic about two inches above the batter head and two inches from the rim of the drum. The mic should tend to point towards the centre of the head but if hi-hat spill starts to become a problem, the mic should be angled to point away from the hi-hats. Noise gates may be used to keep unwanted spill out of the snare mic, but unless you have a gate with frequency conscious keying or can patch an equaliser into the side chain, you are likely to either lose snare beats or trigger the gate from the hi-hat. Moving the hi-hat further from the snare drum can help, but most drummers insist on leaving everything where they feel most comfortable - most unreasonable if you ask me.
In terms of EQ, a little lower mid cut may offset the effects of close miking and reduce the boxy overtones which are very often present to some extent.
The motto here is 'Off with his head' unless you are lucky enough to find a set of toms that sound good with both heads fitted. If you have to remove the bottom head, the chances are that the nut boxes will rattle and you will either need to stuff them with Blu-Tak or stick bits of Gaffa tape over them. If it's your own studio kit, consider cutting large holes in the bottom heads leaving an inch or so of head all round and this will avoid such problems.
Once again the internal dampers should be removed and jumped on, and damping achieved either by using impromptu pads of material as in the case of the snare drum, or by using the self adhesive foam rings - on sale in good drum shops everywhere. Don't forget though that a tom tom is supposed to have some tone to it so don't murder it with Gaffa tape. If you want to end up with a kit that sounds like a suitcase full of Swarfega, save yourself the expense of a drum kit and use the real thing.
"Try rolling back the carpet to experiment with a more live sound."
Drummers have their own ideas about the tuning intervals between toms and this will be influenced by the number of toms in the kit, but my preference is to avoid accurate musical intervals as these tend to form dissonances with the rest of the music. For that Simmons falling pitch decay characteristic, try tuning the drum evenly and then slacken off just one of the tensioners until the desired effect is achieved - you need to hit the drum hard to get this effect.
Mic types and their positionings are fairly similar to those used for the snare drum, though the very reasonably priced AKG D190 can also be used to give first class results if you can't afford a set of state-of-the-art microphones. It may also make life easier if you use the same mic type for all the toms with the possible exception of the floor toms to promote a continuity of tone right round the kit. Some engineers prefer to mic the toms from underneath and this is another avenue worth exploring, and is a particularly convenient way of recording Roto-Toms as it keeps the mic safely out of the drummers reach.
If you do decide to have a go at recording double headed toms, consider placing extra mics below the bottom heads or increasing the distance between the mics and the drums, but take care as this can lead to phasing problems. Another alternative is to use a couple of omnidirectional ambience mics a few feet from the kit and mix these in to give a more open sound.
My personal preference is to avoid using discreet cymbal mics altogether and there are several reasons for this, Firstly, cymbals often bleed onto the drum mics to such an extent that their relative level becomes a problem, and that's before you start worrying about ambience mics. Secondly, a close miked cymbal usually ends up sounding more like a gong than a cymbal and the phasing problems caused by the extra mics cause the drum sound to deteriorate as well as the cymbal sound. If you intend to gate the tom and snare mics however, this will change the situation significantly and some extra cymbal miking will then become necessary whether it is in the form of a couple of ambience mics or dedicated cymbal mics. Commercial studios generally use condenser mics for cymbals but for home use, try out whatever you have and see what works. You could also try using C-ducers (See HSR April 85) but these tend to give a duller sound than conventional mics in this application. I have achieved very gratifying results by taping a couple of PZM mics to the walls of the studio close to the kit, and then mixing enough of this captured ambience back into the rest of the drum mix to restore the natural clarity to the cymbals.
If you are fortunate enough to have a well tuned drum kit and a flattering live room in which to record it, then you can use just a single bass drum mic and a couple of ambience mics, the bass drum mic being there only to beef up the natural sound of the kit. In the way of ambience mics, omnidirectionals will give the most natural sound (though they offer sod-all isolation against other sounds in the room) and for the budget conscious studio, again the little Tandy's PZM mics can yield surprisingly good results, even if you don't do all the balancing mods. This technique may be used in conjunction with close miking to achieve a particular sound balance, and you should try rolling back the carpet to experiment with a more live sound.
When committing the drum track to tape, it is nice to be able to spread the drums over at least four tracks so that you can keep the bass drum, snare drum and stereo tom mixes separate. If you're using ambience mics, it's a good idea to allow a further two tracks for these, and the improvement in the cymbal sound and overall clarity of the kit makes ambience miking well worth experimenting with. Try to use separate tracks, even if it means bouncing down the drum track at some stage, because it's important to get a good balance between these different parts of the kit, and you are probably going to want to add some reverb to the snare and toms, but little or none to the bass drum. If track limitations preclude this luxury, then you'll have to add reverb as you record to avoid affecting the bass drum too.
In a conventional studio, the drum balance is easily achieved by referring to the monitors as the drummer plays his party piece next door and in this way, any adverse effects caused by phase cancellation between microphones due to different path lengths will become instantly apparent.
For the home recordist who may have to share a room with the drum kit, life is not so easy, but by balancing the levels of all the drums using the meters so that they give roughly the same deflection will give you a good starting point. In order to give an even subjective level, you will find that the larger toms need to be recorded slightly louder than the smaller ones. Try adding half a dB for each increase in drum diameter of one inch and you will be pretty near the mark. Remember too that your moving coil meters are not likely to be fast enough to follow the envelope of a drum beat so aim to set the levels to peak at a few dBs below 0VU.
That's all for this month but next month I'll be looking at how to treat the drum sounds once they are safely on tape.
Feature by Paul White
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