Stereo Miking Techniques for Acoustic Guitar

Recording Acoustic Guitar

Learn Essential Miking Techniques for Stunning Acoustic Tracks

Ask a handful of engineers how they approach recording acoustic guitars and you’re likely to get a handful of different answers. With so many factors at play — the room, playing style, guitar type, player's skill level, etc. — there is one technique many engineers use from session-to-session for consistency: stereo miking.

While you can always add spaciousness to mono acoustic tracks by utilizing stereo processing, ultimately the only way to capture the sound of an acoustic guitar with depth and accuracy is by using a two-mic setup.

So let’s dive into the three most common stereo techniques for recording acoustic guitar. While you should always experiment with placement and mic choice, generally speaking you will want to use a pair of unidirectional condenser mics placed close to the instrument (approximately 6" to 12" inches away). Mics with a cardioid polar pattern are typically best as they are less prone to picking up ambient room noise, unwanted reflections, and general phase issues.

Spaced Mics - Setup 1

For this setup, two mics are spaced apart from each other at the same approximate height. My preference for the first mic is a small diaphragm condenser pointed at the 12th fret of the guitar to capture higher frequency content and string dynamics.

For the second mic, I use a large diaphragm condenser aimed at the bridge, or slightly behind it to capture the lower frequencies and body characteristics of the guitar.

When using this technique, remember to follow the rule of 3:1 — where the distance between the two mics is at least three times the distance between each mic and the guitar. For example, if mic A is 6" from the 12th fret, mic B should be at least 18" away from mic A — this will help keep phase cancellations to a minimum and provide a smoother sound that will translate well to mono should you decide on that later.

For this setup, remember to keep the two mics about three times the distance from each other as they are from the guitar.

Spaced Mics - Setup 2

This technique is primarily a variation on the previous setup. While the first mic is still a small diaphragm condenser pointed at the 12th fret, the second mic is positioned on a mic stand around the performer's ear level, pointing down either at the bridge or at the strings just in front of the bridge. For a right-handed player, the mic will be positioned over the right shoulder. It should be placed out in front of the guitar and performer, angled back towards the guitar (as opposed to pointing at the ground).

This setup will yield a brighter sound that is slightly thinner, but more open sounding than our first technique. Keep the rule of 3:1 in mind, but experiment with the mic placement slightly to improve the timbre.

This setup will yield a brighter sound with de-emphasized bass — try it in a crowded mix or when a thinner sound is called for.

Stereo X-Y

X-Y, also known as a coincident pair, is probably the easiest and most reliable method for recording acoustic guitar. When executed correctly, it is difficult to get an unnatural-sounding recording with this setup — for several reasons.

First, the mic positioning is similar to that of our own ears, and thus the perceived stereo image tends to sound more natural. Phase issues are less of a concern as well because the capsules are positioned so close. Additionally, sound waves arrive to both mics at roughly the same time, so the resulting tracks are easily mono compatible.

To start, position two small diaphragm condenser mics (a matched pair is ideal) so that one capsule is above the other, nearly touching. The ends of the mics should be split apart at roughly 90 to 120 degrees, forming a "V" shape. Keeping the capsules focused on the 12th fret, experiment by moving the mics further away to capture more of the room, or slightly left or right to emphasize particular frequencies. I find that about 7" back from the 12th fret often yields a sweet spot between the bass frequencies from the sound hole and higher frequencies off the neck. This placement can de-emphasize midrange content, which can sound more natural on an acoustic guitar.

X-Y is always reliable and will minimize phase issues, making your life easier come mixdown.

If you choose to add subtle compression or EQ to balance your stereo acoustic tracks when recording, the power of UAD plug-ins lies in the flexibility to experiment during tracking or mixdown to achieve that perfect mix balance and stereo image. So, remember to be bold while trying these two-mic setups in your next session, and be sure to keep in touch for more studio tips and mix secrets.

— Mason Hicks

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