Recording Acoustic Guitar, Pt. One Revisited

Sound and Recording
B. Thomas Cooper
Editor

Who says recording an acoustic guitar is difficult?

Oh contraire, my friends. Recording an acoustic guitar is no harder than recording any other acoustic stringed instrument. Oh sure, some simple sonic rules apply, but certainly nothing worth getting high strung about.



I’ll begin by addressing a few of the common misconceptions. Most microphones are designed with a general recording purpose in mind, but there are few hard and fast rules that apply to recording. Although a particular mic may seem appropriate for the setting, there are few guarantees. No two acoustic guitars sound alike, no two rooms sound alike, and no two players play alike. Each recording presents a different set of variables.

Some folks believe a good acoustic guitar sound can only be accomplished by placing the microphone inside the sound-hole of the acoustic. My advise is to forget such nonsense, as it falls dangerously far from the truth, and almost always results in a very poor recording. Even a high quality contact condenser mic mounted inside the instrument produces a compromised result and is generally not used for serious recording. You don’t stick your ears in the sound hole when you listen to an acoustic guitar do you? I certainly don’t.

Indeed, microphone placement is key to recording any acoustic instrument, but it need not be difficult. An acoustic guitar has wonderful ambient and dynamic qualities, often overlooked or misunderstood. Try backing the mic away from the guitar a few inches, pointing the diaphragm toward the sound-hole. Relax, and let the instrument breathe. Changing the axis alignment of the mic, even ever so slightly, can produce startling results. Most importantly, listen for the subtle changes, and learn what is meant by ‘critical listening’. Don’t settle for the first sound you dial in. Take your time, and by all means, enjoy the process.

Tips For Recording the Acoustic Guitar Pt. One

Sound and Recording
B. Thomas Cooper
Editor

Who says recording an acoustic guitar is difficult?
Oh contraire, my friends. Recording an acoustic guitar is no harder than recording any other acoustic stringed instrument. Oh sure, some simple sonic rules apply, but certainly nothing worth getting high strung about.



I’ll begin by addressing a few of the common misconceptions. Most microphones are designed with a general recording purpose in mind, but there are few hard and fast rules that apply to recording. Although a particular mic may seem appropriate for the setting, there are few guarantees. No two acoustic guitars sound alike, no two rooms sound alike, and no two players play alike. Each recording presents a different set of variables.

Some folks believe a good acoustic guitar sound can only be accomplished by placing the microphone inside the sound-hole of the acoustic. My advise is to forget such nonsense, as it falls dangerously far from the truth, and almost always results in a very poor recording. Even a high quality contact condenser mic mounted inside the instrument produces a compromised result and is generally not used for serious recording. You don’t stick your ears in the sound hole when you listen to an acoustic guitar do you? I certainly don’t.

Indeed, microphone placement is key to recording any acoustic instrument, but it need not be difficult. An acoustic guitar has wonderful ambient and dynamic qualities, often overlooked or misunderstood. Try backing the mic away from the guitar a few inches, pointing the diaphragm toward the sound-hole. Relax, and let the instrument breathe. Changing the axis alignment of the mic, even ever so slightly, can produce startling results. Most importantly, listen for the subtle changes, and learn what is meant by ‘critical listening’. Don’t settle for the first sound you dial in. Take your time, and by all means, enjoy the process.

Choosing the Right Microphone

When choosing the right microphone for a particular application, an array of external variables come into play, including room acoustics, microphone placement, frequency response, sound pressure, etc. For this reason, different types of microphones are designed to address different sonic properties.

A microphone works by converting acoustic energy into corresponding electrical voltages, through a process known as transduction. There are various methods by which this process can be accomplished, however, the two most common types of microphones used in recording are the dynamic and the condenser.

With a dynamic microphone, a moving conductor cuts the magnetic field of force to produce electricity, or signal. There are two basic types of dynamic microphones, the ribbon mic, and the more popular, moving coil dynamic, in which a coil of wire is suspended within a magnetic field. Sound-waves strike the diaphragm, causing it to vibrate. This in turn causes the coil to vibrate, generating the desired signal. With a ribbon microphone, a thin strip of metal foil (the ribbon) is suspended within the magnetic field. Again, sound waves cause the ribbon to vibrate within the field, resulting in transduction.

There are dozens of companies who manufacture dependable, reasonably priced studio microphones. So many in fact, it would be nearly impossible to discuss all of them in this article. Therefore I will limit my suggestions to a handful of the more popular microphones
readily available at an affordable price.

Shure Bros. SM-57 & SM-58

Manufactured by Shure Bros. for decades without ever undergoing any notable changes.,
these two dynamic microphones have been the foundation of countless legendary recordings. Every studio, no matter how large or small, should seriously consider keeping a couple of these little workhorses around.

The SM-57 produces a unidirectional pattern, limiting unwanted noise, while capturing a warm, fat response. This mic is great for recording loud guitar amplifiers, horns, vocals, etc. and can usually be purchased new for around $100.00

The Shure SM-58 produces an omni-directional pattern, and is great for lead vocals. I have used this microphone for nearly every imaginable recording at one time or another. When all else fails, the SM-58 can always be depended upon for a clear, even response. Like the SM-57, this mic is also available new for around a hundred dollars, and is worth every dime.


The Electrovoice RE-20, another workhorse of the industry, and found in nearly every major studio in the country. Created especially for critical recording, broadcast and sound re-inforcement, the RE-20 produces a flat but fat response over an unusually wide frequency range. This is the microphone most often associated with radio broadcast (disc Jockeys, etc) and is ideal for applications involving sound pressure in excess of 160 dB.
The RE-20 can be purchased for around $400.00.

I would also recommend the AKG C-414. With five polar patterns, this is indeed a versatile microphone, although some may find it a little pricey, as it usually sells for just under a $1,000.00 This microphone is ideal for vocals, brass and woodwinds, and is often a favorite for film scoring.

Predictably, as you become more familiar with the recording process, you’re microphone collection will grow accordingly. Don’t be afraid to experiment with whatever mics you may have available, as there are no hard and fast rules. Information on the subject is vast and easily obtainable, but nothing beats good old hands on experience. Recording should be fun.
Take your time, and enjoy the experience.

B. Thomas Cooper