Acoustic guitar is one of the first things aspiring engineers take a shot at recording. Considering that the average coat closet and attic contain at least one neglected, dusty acoustic guitar, this isn’t a mystery. This acoustic guitar gets played, and eventually, it becomes subject to microphone experimentation.
This is where things become difficult…
How exactly does one mic an acoustic guitar? How do we translate the stringy and luscious tone to a song, making it actually sound good?
The answer isn’t really simple, but it is true: PRACTICE.
The more time you spend experimenting with microphone and production techniques, the better your recordings will sound. Below you’ll find an array of tips to help you on your journey. They aren’t rules. They are merely guidelines.
Good luck, and happy recording!
1. Combat Proximity Effect
Most of you are probably familiar with proximity effect. Even if you’re unfamiliar with the technical term, it’s likely you’ve experienced the phenomena of proximity effect.
Bobby Owinski (author, audio production expert) defines proximity effect as “the inherent low-frequency boost that occurs with a directional microphone as the signal source gets closer to it.” Proximity effect is that boomy, low-mid heavy rumble that engineers tend to avoid. It’s most notorious when heard on a vocal, but the existence of proximity effect also plays an important role in how one approaches recording acoustic guitar.
If you record an acoustic guitar closer than 8 inches with a directional mic, you may encounter some problems.
Things to Try:
- If you must record closer than 8 inches, try switching the mic’s polar pattern to omni. This helps negate boominess.
- It may sound strange, but the sound hole isn’t the best place to close-mic a guitar. An acoustic guitar really sings around the bridge or at the body and neck joint.
- Try putting a cardioid mic 8 inches away from the 14th fret. For more body, tilt it off-axis toward the sound hole.
2. Go Stereo
Stereo acoustic guitar is one of life’s fine gifts. The BIGNESS and finesse that one obtains from stereo acoustic tracking is an audio marvel.
Don’t misunderstand. Mono can be BIG too, but sometimes it’s nice to incorporate space in the stereo field (space meaning spread). Recording in stereo lets the guitar breathe. When an acoustic guitar exists at multiple points in the stereo field, certain characteristics are accentuated or attenuated.
Purpose of Stereo Miking an Acoustic:
- Can make the guitar feel big without it sounding overbearing.
- Accentuating “shimmeriness” and “glisten”. When both sides of the stereo field are utilized, two different parts of the guitar are being represented at the same time. They aren’t identical, thus creating a pleasant kind of contrast. By combining the two different acoustic tones, you get a glistening stereo spread (of course you need to stay away from proximity effect for this to be possible).
- To thicken a thin-sounding guitar. For this method, keep body and mid tones in mind. Maybe try one mic close to the sound hole or body, and throw the other mic on the 12th fret.
Things to Try:
- One mic over the shoulder (fretboard side), and one mic on the guitar’s body.
- Use a ribbon mic to give a tinny, thin-sounding guitar some girth. Then add a condenser to capture upper-range frequencies.
- X/Y config – 8 inches away from the 16th fret. X pointing toward the bridge, and Y pointing toward the 12th fret.
IMPORTANT: MAKE SURE TO PUT THESE IN MONO TO CHECK PHASE.
3. Mic Choice Matters
Ribbon
Depending on the particular mic’s characteristics, ribbons can soften up harsh frequencies. They’re also used to beef up a weak sounding guitar. Quality ribbon mics generally have an ultra smooth and flat frequency response, so they are great for recording acoustic guitar.
Dynamic
Dynamic mics are great for capturing body. For acoustic, they are generally used on the body of the guitar. You could also employ a dynamic microphone to soften up harsh frequencies.
Condenser
The condenser hears all. If you have access to a condenser mic, it will probably end up as your acoustic recording workhorse. Being highly sensitive, having a low signal to noise ratio, and possibly being extremely small, condensers are a fantastic tool in the studio. A condenser mic with a variable polar pattern will help you mold your sound to perfection.
4. Leave Room for Other Instruments
This is both a guitar recording tip and a mixing tip: record with the MIX in mind. It will make your life so much easier in the long run.
Firstly…what does that mean? Having “the mix in mind”?
It means that you record intentionally. Every inch you move that microphone should be deliberate. Every choice should be thought out.
You should be thinking something along the lines of, “since the piano is coming in on the chorus, and the BGVs are panned far left and right, maybe I should record my acoustic with a condenser in mono to cut through the noise…”
If you don’t record with the rest of the song in mind, you may end up EQing on the backend, trying to “fix” what you just recorded. Why not get it right the first time? It’s Al Schmidt’s approach…and it works. You want all tracks sounding like a song BEFORE you start mixing! It’s more fun, more intuitive, and more musical.
Things to Try:
- Use a rough acoustic track before recording drums, bass, and a few other tracks. Once those tracks are recorded, THEN track your acoustic for real. It will give you a better idea of what the song needs.
- Mess with EQ, compression, and other effects right after you record. If you like that sound better, maybe you should consider retracking.
5. For Decreasing String Squeak… This can be an issue depending on the player.
Things to Try:
- Lightly rub some steel-grade wool on the strings. Be careful to only rub the strings.
- Use something like Fast-Fret.
As with most things in audio, it’s all about your ears. No mic placement measurement will ever be perfect. Experiment. Mess up. Find what you did wrong. Record a killer track!
Courtesy of Nadav Biran
More Music Production articles @ The Blogging Musician.