There are several acoustic guitar pickup choices, but some involve alteration to the guitar, which should always be handled by a professional guitar technician. Sound hole pickups are typically installed by the user, and most require no guitar modification or special tools. Acoustic guitar sound hole pickups are magnetic, and pick up vibrations from the guitar's metal strings in the same manner as electric guitars. Sound hole pickups can also be swapped to other acoustic guitars, making them a versatile and cost-effective option.
Loosen the clamps on both sides of the pickup by turning the clamp screws counter-clockwise with a screwdriver. Some pickup models do not have adjustable clamps, and are fitted with a slot on both sides for installation.
Place the pickup under the strings and over the sound hole. The connection wire will protrude from the sound hole.
Slide the pickup forward toward the guitar neck or backward toward the bridge until the centre of both clamps or slots are wedged between the edges of the sound hole. Placing the pickup forward in the sound hole will produce more bass sound, while placing it back toward the bridge will produce more high-end treble sound.
Tighten the side clamps with a screwdriver by turning the clamp screws clockwise. On slotted pickups, a piece of foam within the clamps holds the pickup in place and no tightening is necessary.
Position the connection wire protruding from the sound hole over to one side of the sound hole, and fasten to the side or back of the guitar with electrical tape if desired. The wire may be positioned on any area of the guitar's top you desire as long as it does not interfere with the strings while playing.
Plug a guitar cable into the pickup's jack and connect to an amplifier to test for operation. The jack may be looped over the guitar strap end-pin or left hanging freely. Some pickups are supplied with a cable terminating with a standard 1/4 inch guitar plug, which is plugged directly into the amplifier.
Choose a pickup model that does not require internal wiring installation. Most manufacturers offer pickups of this type, and include a cable attached to the pickup with an input jack or standard guitar plug. Experiment with different pickup placements and angles for different sounds. Magnetic pickups will not work for nylon-stringed classical guitars. These guitars require a different pickup type which must be installed by a repair shop. If you find the pickup to be satisfactory and do not plan to remove it, you may choose to have a guitar repair shop install the wiring internally. A repair person can modify external cables for this purpose and install an input jack in the guitar body.
Pickups that require internal wiring must be installed by a guitar repair person. These units are installed by drilling into the guitar body to attach the input jack. Drilling into the guitar can cause serious structural damage and requires special tools and expertise. Don't tighten pickup clamps too tightly or damage to the guitar finish or wood may occur. The pickup should be snug, and hand-tight is usually sufficient.