5 Best Mics for Acoustic Guitar

5 Best Mics for Acoustic Guitar

If you play acoustic guitar, and are looking to record, you are going to need a good microphone that correctly picks up the guitar’s sound. What is the best mic for acoustic guitar? Let’s take a look at five great options.

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Best Mics for Acoustic Guitar

Shure SM81

The Shure SM81 is far and away the most popular acoustic guitar mic. It shows up on every “top mic” list, and for good reason. It is a high quality, unidirectional condenser microphone. It is constructed of rugged steel for durability (traveling for a gig? No worries!), and comes with a swivel adapter, attenuator switch-lock, foam windscreen, and carrying case. It works on a cardioid polar pattern that only picks up noise from the front and none from the sides. It has a 20Hz-20kHz frequency response. It has a very low noise and high output clipping level and has very low distortion. It has a small diaphragm design so it is light and easy to position. In short, it is a powerful microphone that picks up the sounds it needs to and doesn’t pick up the sounds it shouldn’t. 

Specs:

Polar pattern: cardioid

Frequency response: 20Hz-20kHz

Self noise: 16 dB

Output impedence: 150 Ohms

Dynamic range: 160 dB

Shure SM57

Another winning microphone from Shure, and one that is much more affordable than the SM81. The SM57 can be used equally well for miking instruments or vocals. It is recommended for brass, saxophone, acoustic guitar, snare drums, or guitar amp. It has a cardioid pickup pattern that picks up only noise from the front, rejects background noise and eliminates feedback. It is extremely durable even under the heaviest use, and comes with a break-resistant swivel adapter that can rotate 180 degrees without breaking or falling. Frequency response 40Hz-15,000Hz.

Specs:

Polar pattern: cardioid

Frequency response: 40Hz-15kHz

Output impedance: 150 ohms

Audio-technica ATM450

The Audio-Technica ATM450 has an innovative side-address stick design which allows for easy placement with minimal obstructions. The input comes in from the side so you don’t need to worry about tilting the microphone to get it into position; stand it up straight in front of your guitar and it is good to go. It has a cardioid polar pattern that only picks up noise from the front, so it reduces pickup of sounds from the sides and the rear and improves the isolation of the desired sound source. The ATM450 has a rugged design that will stand up to wear and tear and last for years.The microphone also comes with a windscreen, shock mount, and zippered pouch. 

Specs:

Polar pattern: cardioid

Frequency response: 40Hz-20kHz

Output impedance: 200 ohms

Dynamic range: 152 dB

Rode NT4

The Rode NT4 is basically two microphones in one. It is a stereo microphone that has an X/Y stereo array without the need for a pair of matched microphones and complicated stereo equipment. The mic comes with a rugged microphone case, pop filter/windshield, 5-pin to stereo minijack, RM3 durable microphone clip, 5-pin to dual XLR cable. 

Specs

Polar pattern: X/Y stereo

Capsule/diaphragm size: .5”

Frequency Response: 20Hz-20kHz

Self noise: 16dB

Output impedence: 200 ohms

Dynamic range: 143 dB

Neumann KM184

The KM184 is a great microphone, but it is more expensive than the others on this list. It has a natural, transparent sound, and has very low self-noise to interfere with your recording. It has a cardioid pattern that rejects sounds behind it and only amplifies sound directly in front of it. It can handle high sound pressure levels of up to 138 dB free from distortion. The KM184 can be used for piano, percussion, drums, acoustic guitar, upright bass, violin, cello, woodwinds, and brass. It is also an excellent microphone for stereo and surround recording. It comes with a microphone clip and windscreen.

Specs:

Polar pattern: cardioid

Frequency response: 20Hz-20kHz

Self noise: 13 dB

Output impedence: 50 ohms

Dynamic range: 138 dB

What do all the terms mean? 

So we’ve been through all the mics and all the specs, and thrown around terms like polar pattern, frequency response, ohms, Hz… what are all these things? Let’s break it down so you can make an informed purchase when you decide to actually purchase your new microphone.

Polar Pattern

Polar pattern basically refers to where the microphone picks up the sound from. It is also called directionality. There are a few main polar patterns:

Omnidirectional microphones have equal response from all angles, meaning they pick up sound equally from all around them, a full 360 degrees. Omnidirectional mics have a very natural, open sound, but they also pick up a lot of room ambience. Omnidirectional microphones are also more susceptible to feedback.

Unidirectional microphones are sensitive to sound coming from a specific direction. The most common type is cardioid, or heart-shaped. They have the most sensitivity to sound directly in front of them and least sensitivity to sound directly behind them. Unidirectional mics are great at picking up only the sound you want that is directly in front of them. They also pick up only a third as much ambient noise as omnidirectional microphones. 

Bidirectional microphones pick up most noise directly in front and in back, at 0 degrees and 180 degrees. This can be useful when you have two sound sources, e.g., two vocalists facing each other. 

Frequency Response

Frequency response is the range of sound the microphone can reproduce. The best type for recording musical instruments is called a flat response microphone, meaning it is equally sensitive to all frequencies in its range and reproduces the sound source with minimal variation from the original.

Self Noise

Self noise is self explanatory – it is the signal the microphone reproduces of itself, or the noise the microphone makes when no sound source is present. To measure this, ideally the microphone manufacturers put the entire microphone in a sound-proof container. You want the self noise to be as low as possible, so the noise of your microphone won’t interfere with the sound of your music. 

Output Impedence

This gets kind of complicated and technical, but basically, output impedence is the resistance on the electrical audio signals sent out from the microphone. For our purposes, all you need to know is you want the output impedence to be LOW.

Dynamic Range

The dynamic range is the range between the lowest level and the highest level the microphone can handle. The dynamic range is linked to the sensitivity of the microphone. If the microphone picks up noise outside its dynamic range, the sound will be lost to distortion or hiss. 

Conclusion

There is a lot to learn and understand before buying a microphone for your acoustic guitar, but it is a worthwhile endeavor. Having a mic for your guitar allows you to play gigs or record your guitar and actually be heard properly. You definitely cannot go wrong with the Shure SM81.

Looking to buy a guitar? Check out the best acoustic guitars under 100 dollars, best parlor guitars, or best classical guitars under 2000 dollars!