Pro tips for recording guitars
Capturing the sound of acoustic guitar can be complex. This three-mic setup uses a spaced pair and one central condenser mic at moderate distance.
Capturing great electric and acoustic guitar sounds may not be magic, but it does require an ideal blend of elements. Obviously, the recipe starts with the natural sound of the guitar and player; if the tone isn't there in the first place, there's not much you can do to dress it up with technology. But other factors are also important: the choice of mic; the acoustics of the room you're recording in, the preamp that feeds the mic to your mixer or recorder, and more. Even the mic cable, gauge of guitar strings and the density of the pick play a role.
Fortunately, today there are many more resources available to help you make good guitar recordings than ever before. From affordable mics and preamps to digital tools to improved pickups systems, there's an approach that should work in any situation or budget.
Acoustic guitars can be a challenge to record, especially in a home studio where noise (from items likes computers, fridges, boilers, and neighbors) can be a factor. If you're the one playing as well as recording the part, it can be even more difficult, as subtle positioning of the mics can have a great effect on the sound. Fortunately, there's more than one way to capture an acoustic.
A single mic up close is especially appealing when you're recording yourself. Try combining the mic with the guitar's pickup.
Acoustic guitar, one mic
Some engineers prefer to use a single microphone on acoustic guitar. On the positive side, it provides a single source from which to capture the sound, allowing for easier placement in the mix. This approach typically calls for a high quality microphone, since you're relying on that single capsule to record the entire sound of the instrument. The single microphone also can have its limitations, since it minimizes your ability to shape the overall tone and create a bigger soundfield. However, you can't argue with the countless classics captured with one mic!
The exact model of preferred mic will certainly always be a cause for debate, but many engineers choose small diaphragm condenser mics for their accuracy and ability to capture the percussive attack of the acoustic guitar. Generally, a cardioid pickup pattern — which focuses on sound that's in front of the mic capsule — works well. Some of the more popular models for acoustic recording include the Neumann KM 184, the AKG 451, the DPA-4011, Audio Technica 4041, any of the Schoeps CMC-series.
You can also try using any of the fine omnidirectional mics that are available, such as the Earthworks QTC-series or DPA omnis. Omnis — which pick up sound from all around the capsule — will capture more room sound with less "proximity effect" — a low end boost that occurs when a source is close to a mic — providing what some consider a more natural sound.
Some engineers still like the large diaphragm mics, such as the Neumann U-47, and U-67, AKG 414, Audio Technica 4050, 4060 or Røde NT2, etc. However, these have a slower transient response than their smalldiaphragm cousins, so they don't capture the subtle articulations of the guitar as well. They do, however, sound warm and full.
Speaking of warm, ribbon mics, like the Royer R-121 and R-122, Beyerdynamics M-160, and the Blue Woodpecker can be very effective. With both large diaphragm condensers and ribbon mics, you may want to boost the high-end EQ frequencies (8kHz and above) to get that elusive sound that engineers refer to as "air." Finally, the old standby Shure 57 dynamic mic can work well on acoustic guitar.
To position the mic, start by listening to how the guitar sounds in the room. Move around: Where does the instrument sound best? That's where you should place the mic. More often than not, you'll end up 6-14 inches away from where the soundhole meets the fretboard. Placing a mic right over the soundhole will often result in a boomy sound with excessive lows.
Sometimes placing the mic a foot or two above the guitarist can yield excellent results. Experimentation is key. Grab a pair of closed headphones, head into the recording room, and listen while you move the mic around to find that sweet spot.
Microphone preamps — the devices that make the mic's signal loud enough to go into a mixer or recorder — are also important. All engineers and producers have their favorites. Most mixing boards and even some recorders have built-in preamps, but if you can afford it, invest in a premium outboard model. The best preamps typically provide better dynamic response than their lower-cost counterparts, an all-important factor in acoustic guitar recording. That's not to say you can't capture a fine recording with a mid-range preamp, but there's a reason why platinum engineers use the "good stuff."
The cables that go between the mic and preamp (and the preamp and the recorder) are another factor. You'd be surprised to hear the difference in sound between top-quality cables from the likes of Mogami, Canare, Monster or Zaolla, compared to cheaper wires. Try to keep the cable runs as short as possible for the purest tone.
A spaced pair offers a wide stereo image and captures the full range of the acoustic guitar.
Acoustic guitar, two microphones
There are several ways to record an acoustic guitar with two mics. The spaced pair method begins with one mic on the body and one on the neck. Try to keep the space between the mics three times the distance between the mics and the guitar (i.e., if the mics are 12" from the guitar, they should be three feet from each other). Watch out for phase cancellation — a phenomenon that can make the sound thin and generally weird. Moving mics even a small amount will alter the tone and phase, so use this method with caution, and when you find the right spot, make sure the mics, and the player, stay in place.
This variation of the X/Y miking setup offers a focused tone with a pair of Royer R-122s.
Another approach is called X/Y, also referred to as "coincident pair." Place the mics at roughly a 90-degree angle, so close that their capsules almost touch. Start by pointing the pair to where the neck meets the body and move the setup from there to find the best spot. Moving them closer to the source yields a tighter sound; moving farther away adds more of the room's acoustics to the tone. The late engineer David Baker used a coincident X/Y pair with a spaced pair. (I've used this several times with guitarist Al DiMeola and it provides a full, wide sound with an abundance of detail. I placed a pair of cardioid Schoeps in X/Y configuration directly above the 12th fret of his vintage Martin, about 6" out. That was followed by a pair of Earthworks QTC-1 omni mics about three feet apart and 3–4 feet from the guitar, but slightly higher than the Schoeps. I ran a Focusrite ISA-series preamp on its highest impedance setting for greater high-frequency response and used a Zaolla silver cable plugged directly into the digital recorder at a high sampling rate. The X/Y Schoeps provided the crisp, clean, tight sound, but mixing in the Earthworks added a beautiful sense of space. This worked well because the guitar was the featured instrument; it may not be appropriate for a dense pop production.)
A two-mic approach with a close Shure 57 and a distant Royer R-122. You can send each mic to its own track and mix them to taste.
Acoustic guitar with pickup and microphone
Many of today's acoustic guitars feature builtin pickup systems from companies such as Fishman, L.R. Baggs, Barcus Berry, Bill Lawrence and DeArmond. These allow you to plug the guitar into a DI (Direct Injection) box and record without a microphone.
By themselves, pickups can sound unnatural. However, used in combination with a microphone (or two), a pleasing sound can be found. Try recording the pickup and mics to individual channels so you can blend them freely when mixing.
There have been some advances in pickup technology recently. Examples include the Taylor Expression System (which captures vibrations on different parts of the guitar) and hybrid systems that combine an internal mic with a bridge piezo pickup. Digital devices such as the Fishman Aura and the D-Tar Mama Bear process an acoustic guitar pickup's signal to make it sound miked. All of the above are workable — but not ideal — as a single source for direct recording. If you do record with a pickup only, use an EQ to tame the midrange and add a little top end "air".
Electric guitar recording used to be a nightmare for anyone who didn't have the isolation of a professional studio; in addition to the challenge of capturing an amplifier, there's the affect the loud amp has on your neighbors. Fortunately, there are other options these days.
Close miking a guitar cabinet; the Shure 57 (right) is a classic guitar mic. The sensitive Royer R-122 (left) gives an alternative tone.
Miking an amp
Countless records feature the classic sound of a cranked guitar amp captured with a mic. As with the acoustic guitar, the source is the most important element, so start by getting the amp to sound exactly as you want it.
Many engineers begin with the Shure SM57 dynamic mic. Stick the mic right on the speaker, angle it a bit for that "off-axis" sound, and send it through a good preamp (Neve and API, two classic but costly brands, are popular in professional circles).
Many of the mics discussed in the acoustic guitar section can also work well on an amp or speaker cabinet — especially in combination with one another. Try a Shure SM-57 for "bite," a Royer R-122 for smoothness, and a Sennheiser 421 to capture the guitar's lower register. Place them literally right next to each other to avoid phase issues. A large diaphragm condenser like the Neumann U87 or AKG 414 placed out in the room can add some natural acoustical dimension to the tone. Place each mic on its own track.
Using a direct box
A DI box allows you to take a high impedance unbalanced 1/4" guitar signal and plug it directly into a low impedance, mic level, XLR balanced input on a mic preamp, mixer or recorder. Direct recorded sounds tend to be sterile, but they have their uses. You can use the direct box to split the signal, feeding one branch (the XLR) to the recorder, the other (1/4") to an amp. Mic the amp, but keep the direct signal for later use.
One of these "later uses" is "reamping," taking a track that's already been recorded and sending it through an amplifier for further processing. For best results, use a buffer device such as the ReAmp, which converts the signal from the recorder into a level and impedance that will sound good through the amp. Adjust the tone on the amp, set up the mic, and record the amp's output to a new track. Another reamping device is Radial's X Amp, which can drive two amps at the same time.
Native instruments Guitar Rig 2 is one of several available software guitar amp simulators. These allow quick access to hundreds of sounds.
While purists still opt for the mic and the amp, excellent guitar sounds can be had running though digital guitar preamps like the Line 6 POD series, BOSS GT-8, and others, as well as software amp simulators such as Line 6 Amp Farm, Waves GTR, Native Instruments Guitar Rig 2, IK Multimedia's Amplitube and Universal Audio's Nigel. These simulate the tone of amps, speakers, and effects from many different eras and let you combine sounds in ways that would be difficult in the "real" world. Because they can store preset sounds, you can change tones almost instantly. Some guitarists and producers don't care for the sound or feel of digital modelers, but they can be highly creative tools. And you can always combine them with real amps using the reamping technique described above.
Producer/mixer/composer Rich Tozzoli has recorded guitarists ranging from Al DiMeola to Ace Frehley and has composed for TV clients ranging from Nickelodeon to the NBC Olympics. Special thanks to Royer (royermics.com) for providing the pictures.span>
Finally, before you record, make sure to use a fresh set of strings. They'll sound better and stay in tune longer.