An acoustic guitar produces a wonderful range of sounds from warm bass tones to crisp high notes; a range of 70hz to 700hz. Because guitars are made out of different types of wood, they can produce different overall sounds. Some guitars have an overall warm sound, others are bright, and others might accentuate the midrange sounds. How can you capture those sounds and amplify them?
There are three common means of acoustic guitar amplification.
Use an Acoustic/Electric Guitar
These types of acoustic guitars have internal electronics that capture the vibrations from under the bridge of the guitar and transfer them into a small battery-operated box that is a mini-eq. The options can be a power button, a volume, and a few EQ knobs or faders. The bottom of the guitar has a 1/4 inch plug for plugging a cable into an amplifier or direct box (ultimately into your sound system).
The benefit to this type of guitar is it makes amplification easy. It’s plug-and-play!
However, where I see this method falling short is through the built-in EQ. If the volume setting is too high, then it blasts the input level going into your mixer, even with the gain turned down. While it’s easy to have the guitarist turn it down, it’s one more thing to worry about. Also, when you EQ the guitar, you need to look at their EQ settings and see if they first need adjusting.
Additionally, with these electronics, the sound is not necessarily the same sound you hear if you were in front of the guitar.
Most guitar companies like Martin, Gibson, Alvarez, Takamine, and Breedlove offer acoustic / electric versions of their acoustic guitars. If you have a musician who is considering a new acoustic guitar, they might want to try some of the acoustic / electric versions through a good amp to see if they like that sound.
Use an Acoustic Pickup
An acoustic guitar pickup is a bar that rest in the sound hole of the guitar that picks up the vibrations of the strings. This is similar to the acoustic / electric guitar except instead of the wires going to an EQ, they go out as a 1/4 inch plug. This is a cheaper method.
The benefit is easy amplification just like above.
There are quite a few makes and models of acoustic pickups and thus the quality will vary a lot. As a guitarist, I don’t like the cable hanging down in front of the guitar. Again, we are picking up the way the string vibrates, not the true overall sound of the guitar.
Brands to look for include Seymour Duncan and Dean Markley.
A microphone can be placed in front of the guitar. This method is what you will see in recording studios because it captures that full guitar sound, but let’s look at the practical applications. A microphone on a stand means the guitarist isn’t free to walk around. Movements can change the volume level going into the microphone.
The benefit is that great sound but the setup means the musician is stuck playing in the same spot. While I don’t move around a lot when I play, any movements I would make with this type of setup would require forethought on my part.
Condenser microphones are commonly used. This microphone type has better high frequency reproduction and transient response when compared to a dynamic microphone. Examples includes the Shure SM81LC and the MXL 603S.
Place the microphone at about the 12th fret, about 5 inches back, when you are first trying this method. Move the microphone around to find the spot that produces the sound you want.
These are the three basic ways to mic a guitar. When it comes down to it, it’s a matter of quality or convenience. But the quality factor isn’t all that great in the live setting when a congregation is singing along.