Perhaps you're wondering how to go about selecting the right microphones for your particular ensemble. Or maybe you already have your mics, but you'd like to improve the live sound of your instrument by learning more about mic placement.
The following is a rudimentary primer for miking instruments onstage. It covers the instruments in the rhythm section, which are the ones most commonly encountered in club situations: guitars, bass, piano, and drums. Although by no means comprehensive, this overview should help minimize the deer-in-the-headlights feeling you may experience when faced with a daunting live-sound situation - like when you put up an open mic on a stage peppered with monitors, only to elicit the screeching howl of the dreaded feedback monster.
To offer a broader perspective, I queried three other Bay Area engineers (who also happen to be musicians) for input on their favorite live-sound mics and placement techniques. I spoke to Robert Berenson, the sound engineer for Yoshi's Jazz Club in Oakland; Myles Boisen of Guerrilla Recording in Oakland, who has done his fair share of live-sound reinforcement; and Lee Brenkman, a self-proclaimed audio dinosaur who was the sound guy at the Avalon Ballroom from 1968 until it closed, and who has done the sound at the Great American Music Hall in San Francisco for the past 28 years. Drawing on this combined experience, this article will give you some practical advice on what mics best complement particular instruments and what placement yields the most desirable sound.
The best way to figure out where to place a mic is to listen to the source - in this case, the instrument or amplifier. Try using only one ear to simulate the mono pickup of a mic, and listen up close and also from a few feet away. How does the instrument radiate sound? Put the mic where the instrument sounds best to your ear. Sometimes two mics are necessary to capture the full range of a particular instrument.
Mics have different frequency response characteristics that make them more or less appropriate for specific applications. Analyze the quality of an instrument's sound to decide which mic best suits the job. If the instrument is soft, a tight-pattern condenser might be just the thing for getting a hotter output. If the instrument is loud, choose a mic that can handle high SPLs. Is it bright? Try a mic that will impart a little warmth. Does it have lots of midrange? Perhaps a Shure SM57 would be a good match. Does it sound bassy? Try a large-diaphragm dynamic to capture the lows fully.
You'll always need to use unidirectional microphones in live situations, for isolation of sound sources and to avoid feedback problems with the monitors. If you have problems with the monitors, mics with a tighter pickup pattern (hypercardioid or supercardioid) are best. For area miking (that is, drum overheads), you can use a transducer with a wider pickup pattern. In most circumstances, you will want to put the mic as close to the instrument as possible without interfering with the player's range of motion. This will ensure a more focused sound with less ambient reverberation and bleed from the other instruments onstage.
Just keep in mind that the more open microphones you have onstage, the livelier the stage sound will be, the more spillover you'll get from the P.A., and the more problems you're likely to have with feedback. So try to keep your setup simple and use pickups and directs whenever possible.
Electric guitars. The electric guitar is perhaps the simplest instrument to mic, given that a Shure SM57 aimed at the amp's speaker always does the job well. As an alternative, Lee Brenkman suggests a beyerdynamic 201 for its smooth sound and because it also has prominent upper mids like the SM57 (making it appropriate for guitar amps). Sennheiser's MD 421, MD 409, and E 609 are also good choices.
There are two primary schools of thought for miking a guitar cabinet. Either point the microphone straight into the cabinet and directly at the speaker's voice coil (the advantage being consistency of sound), or put the mic on the edge of the speaker and angle it into the voice coil (for less spiky mids). In both cases, you should place the mic right up against the grille.
Acoustic guitars. Any condenser microphone (such as a Neumann KM 184, a Shure SM81, an Oktava MK012, or an Audio-Technica Pro37) works well for miking an acoustic guitar, as long as the stage sound isn't too cluttered or loud. If the volume is cranked up and the guitar needs to go through the monitors, you may prefer a dynamic mic with good high-end response (two examples would be a Shure Beta 58 and a Sennheiser MD 441) to get sufficient gain before feedback. In a pinch, you could rely on a Shure SM57 or a Beta 57.
If the guitarist has a pickup, try taking it direct. If the sound is too dry and the guitarist is using a lot of effects or EQ at the amp, you may need to mic the amp, using the same approach as for miking an electric guitar amp, and combine that sound with the direct signal. You could also mic the guitar itself and blend that with the direct signal for a fuller sound.
Thoughts on microphone placement for acoustic guitar are varied. Some folks want to stick a mic right in front of the sound hole, but this approach is not recommended. Low end builds up at the sound hole, and with the mic at this position, you'll get a lot of boom and not enough sparkle. Instead, you should put the mic up close and in front of the spot where the neck joins the body (around the 14th fret), and angle it toward, but off-axis from, the sound hole (see Fig. 1). This placement should give you a nice blend of string harmonics, resonance, and pick sound.
Electric bass. Although it's standard practice to send the bass direct through the P.A., in some circumstances an engineer will also mic the bass cabinet. The mic you choose should capture lots of low end. Large-diaphragm dynamics such as the Electro-Voice RE20, AKG D 112, Audix D4, Shure Beta 52, and Sennheiser E 602 are good choices. Another good choice would be the Sennheiser MD 421.
If the bass cabinet has a mix of 10-inch and 15-inch speakers, you have a couple of options. For more low-end oomph, put a mic on the 15-inch speaker. If you're a funky slap-and-pop bass player, try putting a mic on one of the 10-inchers or on the horn for more high-end definition and better transient response. Keep in mind that the direct injection (DI) box will give you plenty of low-end fundamentals and that extra twang, so a little lower midrange support from a miked cabinet can fill out the sound.
Acoustic upright bass. It is desirable to take a direct signal from an acoustic bass pickup, though most double-bass players (especially jazz cats) wrinkle their noses at DIs because they never sound the way players like them to sound. In such a case, you should also mic the bass. It's prudent to retain the option to use the direct sound, however, because in a loud situation where you may not get enough gain or definition from the mic, you can still boost the level to give the bass presence in the mix.
The output of an acoustic bass is relatively low, so you have to put the mic in as close as possible. Unidirectional mics are prone to proximity effect (a boost in the low frequencies) when placed very close to a sound source, so you may need to roll off some of the lows. Electro-Voice's RE20 has less proximity effect because of its lateral port design, so it's a good choice for avoiding excessive low-end boom. Sennheiser's MD 421, kick-drum microphones such as beyerdynamic's TGX 50, and condensers (in softer volume bands) such as AKG's C 535EB are also fine for bass. Tiny clip-on condensers are quite popular as well, such as Audio-Technica's ATM35, Crown's GLM100 (this is an omnidirectional, but according to Brenkman, it should work because it's in so close to the bass), and Applied Microphone Technology's SB. You can fasten these low-profile microphones to the tailpiece, to an f hole, or to the ridge that's just above the waist of the instrument. Don't clip them on the bridge, however, because that would inhibit vibrations.
You can mic a double bass in a number of ways. Myles Boisen suggests starting with a dynamic mic with good low-frequency response (preferably a large-diaphragm type, like the RE20 or MD 421), or perhaps a large-diaphragm condenser such as the AKG C 414 B-ULS set to hypercardioid. Put the mic in front of the bridge, but not in front of the f hole, where you get low-end buildup. Boisen has also had good experiences with wrapping an MD 421 in a piece of foam and wedging it in the tailpiece of the bass, pointing up at the bridge. This allows the bassist complete freedom of movement while maintaining good isolation.
Another novel approach from Robert Berenson is putting an MD 421 (with a foam windscreen) on a short boom and placing the mic so that the screen is physically touching the side of the bass in the notch at the instrument's waist (see Fig. 2b). Have the player lean the bass against the microphone so that it picks up the instrument's vibrations directly. Though this method won't capture a lot of string or bow noise, it isolates the instrument pretty well from the rest of the band. You could also try simply putting an RE20 slightly below the bridge out of the bow's way, angled up about 45 degrees, and aimed at the area in between the bridge and the f hole (see Fig. 2a).
Tickling the Ivories
Electronic keyboards. Most engineers prefer to get a direct feed on electronic keyboards. If the keyboardist has an amp and prefers that sound, you could mic the cabinet (as you would a guitar amp with a Shure SM57) and combine that sound with the direct signal. Going direct or using a direct box is generally better, because you tend to get a cleaner sound. In the case of a Fender Rhodes suitcase piano, Brenkman recommends going direct and miking the speakers on the piano to represent the Fender Rhodes sound fully. And with Hammond organs, he's had good results miking both sides of the Leslie cabinet, putting a Sennheiser MD 421, a Sennheiser E 602, or an AKG D112 on the bottom and a Shure SM57 or Shure Beta 57 on the top.
Piano. For miking grand pianos, engineers often favor condenser mics such as AKG's large-diaphragm C 414 B-ULS or Neumann's small-diaphragm KM 184 because of their excellent high end and transient response. Ideally, you should use a pair of mics to capture the low and high strings (see Fig. 3a). Place one mic several inches over the bass strings and the other over the high strings, and angle them apart for greater separation. The closer you get to the hammers, the more attack you'll get; the farther away from the hammers, the mellower the tone will be.
If the environment is loud, try securing the mics inside the piano and closing the lid for greater isolation. You can do this using a pair of PZMs such as Crown's PCC160 (a cardioid boundary mic) and taping them to the underside of the lid. Alternatively, Berenson recommends making little slings out of gaffer's tape and attaching two C 414 B-ULSs to the bars under the lid. You could also clamp the mics to the soundboard (using a piece of foam to protect the wood) with LP Claws or similar mic clamps. A single SM58 pointing into one of the soundboard holes will also do the trick if you have only one input and the piano is going through the monitors (see Fig. 3b).
If you're dealing with an upright piano, open the top and place a split pair of microphones inside, aiming slightly toward the hammers to capture both the low and the high keys. Condensers are preferable, but SM57s work quite well, too. You could also mic the piano from the back, taking time to find the sweet spot. Remember to listen - and to think from the mic's perspective. Another option is to take the front off by the player's feet and to mic the strings from that angle (if the player isn't stomping the pedals or the floor too vigorously, that is!).
The Driver's Seat
Drum set. Drum sets vary in size, number of components, tonal quality, and head configurations. But most standard kits have a snare drum, a bass drum, a floor tom, one or more rack toms, a hi-hat, a ride cymbal, and a crash or two. The subject of miking drums is immense, and I could easily write an entire article just about that, but here are some basics.
A fat but crisp sound is desirable for snare drum, and a Shure SM57 is the workhorse for capturing this essence. An Electro-Voice 408 or a Beta 58 can also sound very good on snare. Place the mic at about 11 o'clock from the player's perspective, between the hi-hat and the rack tom, about two inches from the head and angled toward it. For more lows, angle the capsule closer in toward the head; for a crisper attack, move the mic slightly farther from the head and point it more toward the center of the drum. If you want to get some extra sizzle from the snare wires for a funky sound, put an additional mic on the bottom head, pointing up at the wires. Use a dynamic that has a lot of high end, such as beyerdynamic's 201, and flip the phase of the mic on the bottom head to avoid phase cancellation.
A punchy kick-drum sound with a lot of low-end oomph makes the rest of the band really pump. Quite a few mics are designed specifically for kick-drum miking, including the AKG D112, Shure Beta 52, Audix D4, and Sennheiser E 602. Usually a kick drum will have a hole in the front head. Put the mic just inside the drum to start. For more attack, move the mic closer inside and aim it at the beater. For a fuller, rounder sound with less attack, draw the mic back farther and angle it slightly away from the beater. If there is no hole in the front head, start with the mic about two to four inches in from the rim and point it at the head, adjusting the angle to get the desired sound. Listen up close to the drum with one ear as someone plays, find the spot where it sounds the way you like, and put the mic there. Refrain from placing the mic at the very center of the drum - that's a dead spot.
Miking toms can pose a challenge if a drummer has a lot of cymbal stands. Fortunately, you have the option of clip-on tom mics such as the Shure SM98, as well as mic-mounting clamps that come in handy for fastening tom mics in place and neatly out of the way. Good tom mics include the Sennheiser MD 504 and E 604, the Audix D2, and the Shure SM57. The Sennheiser MD 421 is a favorite on floor toms for its low-end response. Place the mic near the rim of the drum, pointing down at the head, and adjust the angle and distance for more low end or more attack. If you want greater separation, angle the mics apart.
The use of overhead mics is standard for capturing the cymbals and the overall kit sound, and a split pair will pick up both sides of the kit. Condenser mics are ideal for overheads because of their excellent high end and natural transient response. Examples are the Neumann KM 184; the AKG C 414 B-ULS, C 451, and C 460; and the Audix SCX-1. If you have only one overhead, place the mic centrally over the kit, and move it around to compensate for the playing style and the kit's characteristics (that is, quiet ride cymbal, loud snare, and so on). Just keep the overheads out of the monitors to avoid feedback. If the hi-hat needs more bite, place a small-diaphragm condenser mic a few inches above the hi-hats, angled at the area just below the cup.
Miking stage instruments is a subjective art, and there are nearly as many opinions as there are engineers. By now, though, you've picked up enough pointers to start miking the most ubiquitous instruments in standard venues (we'll follow this article with one about miking other types of stage instruments - such as strings, woodwinds, and brass - in an upcoming issue of Onstage).
If you have some time and the luxury of access to a variety of live-sound mics, the next step is to experiment a little with selection and placement before you have a show. Keep in mind the constants - namely, the proper etiquette for avoiding feedback, and close miking with unidirectional mics for maximum pickup and isolation. Use this article as a guide, but remember: ultimately you should rely on your ears to determine the best mic placement for optimum sound.
A primer on types of microphones and mic placement provided by the University of California, Santa Cruz, Division of the Arts.