Acoustic guitar is one of the hardest instruments to record well in a home environment. Here is what actually works, from someone who has done it right and wrong in the same room.

Acoustic guitar is one of the most unforgiving instruments to record in a home environment.

Electric guitar gives you control. You can use a DI, you can use an amp simulator, you can layer the signal with effects that mask room problems and compensate for an imperfect recording environment. Acoustic guitar does none of that for you. The microphone picks up the instrument and the room simultaneously and you cannot separate them after the fact. Whatever is in the room when you press record is in the recording.

That characteristic makes acoustic guitar recording a direct test of your environment, your technique, and your signal chain in a way that electric guitar recording is not. It also makes it enormously rewarding when everything comes together, because a well-recorded acoustic guitar in a well-treated space through a clean signal chain sounds like something alive in a way that very few other recorded sounds match.

I have been recording acoustic guitar in my home studio for years, through the lens of an electrical engineer who has spent significant time understanding why things go wrong before I figured out how to make them go right. Here is what I know.

THE ROOM IS THE FIRST INSTRUMENT IN THE RECORDING

I have written about room acoustics in the context of home studio setup and the same principles apply here, but acoustic guitar recording makes those principles urgent in a way that other instruments allow you to ignore.

When you record an electric guitar through an amp, the microphone is typically placed very close to the speaker cabinet. The ratio of direct signal, what comes directly from the speaker, to room signal, the reflections bouncing off your walls and ceiling and floor, is extremely high in favor of the direct signal. Room problems are less audible because the direct signal is overwhelmingly louder than the reflections.

Acoustic guitar recording is the opposite situation. The microphone needs to be placed at a distance from the instrument to capture the natural sound of the guitar's body and top. As that distance increases, the ratio of direct signal to room signal decreases. By the time you are at a foot or more from the guitar, which is often the right distance for a natural acoustic sound, the room is a significant contributor to what the microphone is picking up.

An untreated room introduces reflections that arrive at the microphone milliseconds after the direct signal. Those reflections cause comb filtering, a phenomenon where certain frequencies are reinforced and others are cancelled by the interference between the direct sound and its reflections. The result is an uneven frequency response that changes depending on where you move the microphone and that cannot be fully corrected with EQ after the recording.

The practical solution before you place a single microphone is to record in the most acoustically controlled space available to you. A room with soft furnishings, irregular surfaces, and acoustic treatment in the corners and at the first reflection points will produce a significantly cleaner recording than a hard-walled, parallel-surfaced room regardless of the quality of everything else in the signal chain.

If your recording space is untreated and you cannot treat it, the next best option is to record as close to the instrument as the sound allows, minimizing the amount of room the microphone picks up, and to accept that a closer, drier sound is what the space can produce honestly. A dry, close-miked acoustic guitar sound can be excellent. A distant acoustic guitar sound in a bad room is almost always a problem.

MICROPHONE CHOICE AND WHY IT MATTERS LESS THAN YOU THINK

Most acoustic guitar recording content starts with microphone recommendations and spends the majority of its time there. I am going to spend less time on microphone choice than you might expect because the room, the placement, and the instrument itself are all more important variables.

That said, the type of microphone you use shapes the character of the recording in ways worth understanding.

A small diaphragm condenser microphone captures the transient attack of a picked or strummed string with more accuracy and more top-end detail than a large diaphragm condenser. It tends to produce a more precise, detailed representation of the guitar's sound. This makes it the choice for fingerpicking styles where the individual notes need clarity and separation, for recording in a treated room where that detail is a feature rather than a liability, and for applications where the guitar needs to sit in a dense arrangement without taking up too much space in the mix.

A large diaphragm condenser produces a warmer, fuller sound with a characteristic presence that flatters the body frequencies of an acoustic guitar. It is more forgiving of minor placement errors and it tends to produce a sound that sits well on its own or in sparse arrangements. It is also more sensitive to room reflections, which means the room treatment considerations I described above matter even more when you are using one.

A dynamic microphone on an acoustic guitar is a choice most people do not consider and it is worth considering if your room is problematic. A dynamic microphone, like the SM57 or the SM7B, has a tighter polar pattern in practice and picks up less of the room than a condenser does. The high-frequency extension is less than a condenser, which means the recording will have less of the air and sparkle that characterize acoustic guitar at its best, but in a difficult room a dynamic can produce a more usable result than a condenser that is faithfully capturing a bad acoustic environment.

The microphone I reach for most often for acoustic guitar recording is a small diaphragm condenser in a treated space. The specific model matters less than the placement, which I will address next.

MICROPHONE PLACEMENT: WHERE THE RECORDING IS ACTUALLY MADE

This is the part of acoustic guitar recording that has the most direct effect on the result and that receives the least precise treatment in most guides.

The acoustic guitar produces different sounds from different locations. The soundhole is the most intuitive place to point a microphone and one of the worst choices for recording. The soundhole produces a boomy, bass-heavy sound that is the acoustic signature of the instrument's resonating chamber amplified to its maximum. Close-miking the soundhole produces a recording that is disproportionately heavy in the low-mid frequencies and lacks the clarity and presence that makes an acoustic guitar recording interesting. Back away from the soundhole, angle the microphone toward the 12th fret, and the recording opens up significantly.

The junction between the neck and the body, around the 12th to 14th fret, is the sweet spot for most acoustic guitar recordings. At this position you are capturing the string vibration directly rather than the amplified resonance of the body cavity, which produces a more balanced frequency response with clear high end, defined midrange, and controlled low end. Experiment with the angle between the microphone and the guitar surface. Pointing directly at the strings produces more attack and brightness. Angling toward the body adds warmth. Finding the position that balances attack and warmth for the specific guitar and the specific part you are recording is the primary placement work.

Distance from the guitar affects the ratio of direct signal to room signal as I described above. Start at approximately eight to twelve inches from the 12th fret and adjust based on what you hear in your headphones. Closer produces a drier, more intimate sound with more pick noise and finger noise, which may be appropriate for some styles and problematic for others. Further produces a more natural, open sound that includes more room and more of the guitar's acoustic projection.

If you have two microphones available, a classic stereo approach places one microphone at the 12th fret and a second microphone aimed at the body around the upper bout, the wider part of the guitar near the waist. Pan the two microphones slightly apart in the mix. This technique captures both the articulation of the strings and the warmth of the body in a way that a single microphone cannot fully achieve and it produces a wider, more three-dimensional stereo image than a mono recording. If you are only presenting in mono or if the track needs to sit in a dense arrangement, a single well-placed microphone is the better choice.

THE SIGNAL CHAIN: WHAT HAPPENS BETWEEN THE MICROPHONE AND THE RECORDING

Your acoustic guitar recording is only as good as the weakest link in the signal chain between the instrument and your DAW.

The microphone preamplifier is the component most people overlook. Every audio interface has built-in preamps and the quality of those preamps varies significantly between budget and professional interfaces. A microphone converts acoustic energy into an extremely low-level electrical signal. The preamp amplifies that signal to line level for recording. A noisy or colorful preamp is adding something to the signal at the most vulnerable point in the chain, when the signal is at its weakest and most susceptible to contamination.

A quality audio interface with clean, low-noise preamps is the most important single piece of equipment in your acoustic guitar recording chain outside of the room and the microphone. I have written about the Focusrite lineup elsewhere on this blog and it remains a strong recommendation for home studio producers who want clean preamp performance at a price point that makes sense for independent musicians.

Phantom power is required for condenser microphones. Your interface should provide 48V phantom power and you should confirm it is enabled before wondering why your condenser is not working. This is a more common troubleshooting issue than it should be.

A high-pass filter on the microphone channel, cutting frequencies below 80 to 100 Hz, removes the low-frequency room rumble and handling noise that microphones pick up even in relatively quiet environments. Most audio interfaces and DAWs have a high-pass filter available on the channel. Use it on acoustic guitar recordings almost without exception. The frequencies it removes are not musical frequencies for acoustic guitar and their presence in the recording adds mud without adding information.

THE PERFORMANCE VARIABLES MOST PEOPLE IGNORE

The instrument and the player are variables in the recording that no amount of microphone technique or room treatment can compensate for.

A guitar that is not well set up, with high action, buzzing frets, or intonation problems, will not produce a good recording regardless of how well everything else is executed. If your acoustic guitar sounds good played acoustically in a quiet room, it will record well. If it sounds problematic acoustically, the recording will faithfully document those problems. Address the instrument before you address the recording chain.

Fresh strings make a significant difference to acoustic guitar recordings. A guitar with old strings records with less brightness, less sustain, and a duller transient attack than the same guitar with fresh strings. Change strings before any important recording session and give them a few hours to settle and stretch before recording if possible.

Pick noise, the sound of the pick striking the string before the note speaks, is captured more prominently on a condenser microphone than most players expect. If pick noise is problematic in your recordings, try a thinner pick, a softer attack angle, or a microphone position that is slightly more aimed at the body and less at the strings.

Finger noise on wound strings, the sound of fingers sliding between positions on the lower strings, is also captured prominently in close-miked acoustic recording. It can be a character element in some recording styles and a distraction in others. Be aware of it and make a deliberate choice about whether it serves the recording.

WHAT THIS SOUNDS LIKE IN PRACTICE

The acoustic guitar recordings that have come out of my home studio setup have gotten progressively better as I have addressed the variables in the order that matters: room first, then instrument, then signal chain, then placement, then performance. Each of those improvements compounded on the ones before it.

The version of acoustic guitar recording that most home studio producers are doing, buying a decent condenser microphone and plugging it into a budget interface in an untreated room, produces recordings that sound like a decent condenser microphone in an untreated room. That is not what acoustic guitar recording is supposed to sound like. It is what happens when the room and the signal chain problems outweigh the quality of the instrument and the performance.

Work from the outside in. Fix the room before you change the microphone. Understand the placement before you reach for EQ. Get the performance right before you reach for the microphone position. The compounding returns on doing things in the right order are real and they show up in every recording you make after you get the order right.

Tony Oso

Stream Tony Oso at tonyosomusic.com/music

Subscribe at tonyosomusic.com to stay connected to new music, new posts, and the ongoing conversation about making music well in a home environment.