Acoustic Guitar Pickup Primer: Part 2 Internally Mounted Microphones
As mentioned in part 1 of this series, there’s more than one way to amplify your acoustic guitar. There are several types of pickups and each has its own strengths, and sadly, weaknesses. Some of these weaknesses can be compensated for by combining two or more pickups together and/or running the signal through one of the more interesting processors created specifically for acoustic guitar.
Internally Mounted Microphones
A miniature microphone mounted inside the guitar gives the guitarist the ability to move about the stage. Most musicians and soundmen agree that a mic’d acoustic guitar sounds the most natural.
Placement is crucial, as with an external mic, so many of the mics designed for this purpose are mounted on a flexible gooseneck. This gooseneck may be attached to a brace on the top or back of the guitar or may be suspended from the pickup if used in conjunction with a magnetic soundhole pickup. There are some models the gooseneck extends from the endpin/output jack, which also houses the batteries and preamp.
If no gooseneck is used the mic could be placed anywhere on the inside of the guitar (the manufacture usually has recommendations). It is not unusual for the mic’s element to be encased in a square of foam.
Some mics are integrated into the magnetic pickup or rim-mounted pre-amps themselves, eliminating any placement concerns.
To capture all the beautiful nuance of an acoustic guitar a wide frequency response such as those of a condenser microphone are required. Condenser mics require a source of power, usually a 9-volt battery (though smaller disc type batteries such as those used in watches are sometimes used) which is also mounted inside the body of the guitar. If the guitar has a rim-mounted preamp, the battery is usually accessed there. Otherwise a battery clip is usually mounted to the neck block of the guitar where the weight of the battery is easily accommodated.
Sadly, internally mounted mics are very prone to feedback. The use of in-ear monitors (basically ear bud headphones) helps combat this problem, but most venues use traditional wedge shaped monitors. A good soundman can often nix the offending frequencies that are feeding back, which is something he/she would do during soundcheck.
In band situations the mic may pick up other sound sources such as a loud drummer, sometimes louder than the guitar itself which virtually renders the pickup useless.
Since mics produce the most realistic guitar sound, but are difficult to control at concert volumes, they are often used to augment the sound (usually the high frequencies) of more manageable, feedback resistance pickup systems.
Jake Kelly is a man on the constant search for enlightenment, if anyone finds it let him know so he can get some. For more of this hombre’s ramblings and the rest of L2P check out L2Pbandspace and L2Pnet.com.