Best Microphones For Miking Acoustic Guitar


So it’s time to record or perform live and you’re wondering which microphone(s) best capture the beautiful tones of an acoustic guitar.

When choosing a microphone (or pair of microphones) to capture the sound of an acoustic guitar, look no further than the famous Neumann KM184 (link to check the price on Amazon). This small diaphragm condenser is an industry go-to for capturing the true sound and subtleties of acoustic guitars.

So what makes a great acoustic guitar microphone and why is the Neumann KM184 the best choice? Let’s discuss the answer to these questions in this post!


Disclaimer:

“Best” is a dangerous word. There is really no such thing as a “best microphone” for any situation. The microphone(s) listed in my Recommended Microphones And Accessories” page are simply my recommendations. These recommendations are based on my own experience and are mindful of budget. It would be easy to suggest an ELA M 251 or U47 for most scenarios. However, these tube mics are very expensive, putting them out of a hobbyist’s price range and making it difficult for professionals to make their money back on the gear.

Another important note is that the microphone or equipment you choose is not the most important part of recording audio. In fact, there are many factors that are arguably more important than the choice of microphone. These include:

  • Performer (whether a musician, speaker, or otherwise)
  • Instrument
  • Microphone technique/placement
  • Number of microphones used
  • Natural sound of the room
  • Content (whether that’s the song, discussion, or otherwise)
  • Signal chain (including mic cable, preamplifier, console, and/or interface/computer)

With that being said, some microphones and gear suit some instruments better than others, prompting this series of articles under “Recommended Microphones And Accessories.”


What Does An Acoustic Guitar Sound Like?

When picking the ideal microphone for an instrument, it’s critical that we understand the sound and projection of that instrument. So what does an acoustic guitar sound like?

Frequency Range Of Acoustic Guitar

  • Overall Range: 82 Hz ~ 7,000 Hz
  • Fundamentals range: 82 Hz – 1175 Hz (6 string, 22 frets, standard tuning)
  • Harmonics range: 162 Hz ~ 7,000 Hz (upper harmonics are much weaker, though still present above 7 kHz)

Sound Of Acoustic Guitar

The acoustic guitar has a top plate, a hollow body and a sound hole that provide natural amplification. The top plate helps to project the higher frequencies of the guitar while the hollow body and sound hole amplify the lower, fundamental frequencies of the guitar.

So when miking an acoustic guitar at a distance, it’s often best to point a directional mic at the body of the guitar. However, most often we’ll close-mic an acoustic guitar and want to point the microphone(s) near the 12th fret rather than at the body/sound hole.

The Neumann KM184 sounds awesome in both situations!


A Note On Acoustic Guitar Pickups

Some acoustic guitars come with electric pickups. Often these are tiny electret microphones just inside the sound hole of the guitar.

In live situations, I’d typically suggest going with these pickup mics rather than external microphones. The pickups “stay put” inside the guitar, providing a consistent capture and no bulk outside of the guitar itself.

This article is best suited for acoustic guitars without electrical pickups and for recording acoustic guitars in studio.


What Makes An Ideal Acoustic Guitar Microphone?

So now that we know a bit more about how to position a microphone to capture the best acoustic guitar sound, let’s discuss a short list of the critical specifications that make up a great acoustic guitar microphone:

  • Flat/extended frequency response: Choose a microphone with a flat frequency response to accurately capture acoustic guitar. Although the harmonic content of guitar strings isn’t very strong in the high-frequencies, having extended high-end helps to capture the air and character of the guitar and room. Extended frequency responses allow microphones to capture sound in a way that’s similar to how we naturally hear the guitar.
  • Accurate transient response: It’s always preferable to have a pronounced transient response when miking stringed instruments. There is a lot of information in the transients of all the string harmonics and often many strings will be played in short succession.
  • Low self-noise: Condenser microphones are often the best bet for miking acoustic guitar. These mics are active and therefore have self-noise. Choosing a quiet active microphone will help to further capture the subtle nuances in the sound of acoustic guitar performance.
  • Directionality: Select a direction microphone to better suit the various miking techniques used in recording acoustic guitars.

This is what we should have in mind when thinking of a microphone to record acoustic guitar. Let’s now discuss how the Neumann KM184 fits the bill according to the above criteria.


Miking Acoustic Guitars With The Neumann KM184

Neumann KM184 Pair

Since my first mentor showed me a pair of Neumann KM184s, they’ve been my go-to for miking acoustic guitars. They are the preferred microphone of many engineers for both mono and stereo recording of acoustics. 184s sound clean, professional, and really allow an acoustic guitar to “pop” out in a mix. Let’s look at the important specs here:

Frequency Response Of The Neumann KM184

The frequency response of the Neumann KM184 is given as 20 Hz – 20,000 Hz. The KM184 frequency response graph is as follows:

The KM184 has a beautifully flat response in the range of acoustic guitar frequencies. This means a clean, accurate capture of the harmonic content of the guitar.

The slight roll-off in the lower frequency range helps to naturally remove rumble from the guitar channel without causing the guitar to sound thin. Note also that the 184 is a cardioid directional mic and so the proximity effect will likely bring up some of the low end when the guitar is close-miked.

The gentle boost in the high frequencies adds “air” and “brilliance” to the sound of the guitar. This slight boost of the weaker harmonics helps push the guitar through the mix and captures the sound of the guitar similarly to how our ears would (only brighter).

Transient Response Of The Neumann KM184

Other than thin diaphragm ribbon mics, small diaphragm condensers (SDCs) offer the most accurate transient response.

Some SDCs even overshoot, producing an exaggerated transient response. However, the KM184 is nearly spot on.

There’s so much information in the transients of guitar strings (both in the fundamental frequencies and harmonics). The KM184 provides a beautifully accurate reproduction of this nuanced info.

Self-Noise Of The Neumann KM184

Speaking of nuances, self-noise is an important specification to look out for when choosing an acoustic guitar mic. The quieter the mic, the better it’s suited to capturing all the finer details of the acoustic guitar. These details could be hand repositioning, string “squeak,” wood creaks, or any other sound to help the acoustic guitar sound more intimate to the listener.

The Neumann KM184 has a self-noise rating of 13 dB-A. Although this isn’t extremely quiet, it won’t be noticeable in most iso-booths (unless the sound dampening is top-notch).

Directionality Of The Neumann KM184

The Neumann KM184 is a cardioid microphone. Let’s look at its polar pattern:

Cardioid patterns work amazingly well when miking acoustic guitars at close range or at a distance.

Pointing the KM184 at an acoustic guitar from a distance will capture a clean, full sound of the guitar with no worries of an exaggerated bass response (due to the proximity effect). The 184 will capture the acoustic guitar similarly to how our ear do naturally.

When close-miking an acoustic with a KM184 (or any other directional mic), it’s standard practice to point it at or near the 12th fret. The slight off-axis colouration of the 184’s cardioid pattern will help reduce the sound coming from the sound hole (lower resonances) while still picking up the full character of the guitar. The helps to reduce the proximity effect and capture an accurate sound when close-miking.


Recap Of The Neumann KM184

Regardless of miking technique, the Neumann KM184 is my recommended microphones for acoustic guitars. Its response to both frequencies and transients suits the sound of an acoustic guitar perfectly no matter what playing style is used during the performance.

For a full, rich, accurate, nuanced sonic capture of an acoustic guitar, the Neumann KM184 is your best friend!

For all the My New Microphone mic/gear recommendations, please check out my page Recommended Microphones And Accessories.

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