Here are 8 great tips and techniques for miking up guitar amplifiers in the recording studio.
Although audio engineers have been recording electric guitars for many decades now, there are no strict rules when it comes to exactly how it should be done. That said, there are several guitar amp miking techniques that turn up regularly in recording studios. Each mic technique will yield a different sound, so find the one that's appropriate for your music.
While these tried and true amp miking techniques make good starting points, experimentation is called for. Even the slightest change to a microphone's placement in front of a guitar speaker can result in a significant change in the way it “hears” the amp. The key is to listen critically to how changing your microphone's placement is impacting the sound reaching your recording rig or DAW.
1. Place a dynamic microphone pointed at the center of the amp's speaker cone, up against the grille cloth. If the cabinet has more than one speaker, find the speaker that sounds the best and point the mic at it. This placement is good for a driving, punchy sound. Some engineers prefer pointing the microphone about a third of the way toward the rim of the speaker. Again, experiment to find what works for your situation.
2. Point the mic at or near the center of the speaker cone, a short distance away. This results in some of the room’s ambience being mixed in with the amp tone. Experiment with various distances; try placements between ten inches and two feet. If you're using a cardioid mic, moving the mic away from the cab will decrease the bass response.
The Heil Sound PR40 Large Diaphragm Mic is a workhorse in the studio and sounds especially good teamed with ribbon mics when tracking guitars.
3. Place a condenser mic at about a 45 degree angle from the front of the speaker cabinet, about 8 to 12 inches away. Set the mic to a cardioid pattern. Usually the mic is placed directly in front of the speaker, but it can be higher. This placement is good for clean guitars when you want lots of highs and mids.
The AKG C 414 XL II Condenser Microphone is a go-to unit for many engineer. This latest version of the C 414 has nine selectable pickup patterns giving it great versatility.
4. Try miking your amplifier at different distances, from three feet to the length of the room. Large diaphragm condenser mics are good for this, because they pick up more low end. If your condenser can switch to omni-directional, and if you're recording in a rectangular or square room, place the amp one or two feet from a wall, and put the mic in the center of the room. As you'd expect, you'll get a lot of room ambience this way. Keep in mind, you might also pick up some sounds from the environment, such as cars and yapping dogs.
5. If you have two microphones and an open-back amp, try miking both the front and back of the amp. You can either use two dynamics, two condensers, or one dynamic and one condenser. If you use a condenser, set it to cardioid. Try positioning each mic about eight inches from the cabinet. Place one of the mics slightly to the left, and the other slightly to the right. Experiment until you get a sound you like. Note, depending on how your microphones are positioned, you could potentially run into some phase cancellation issues, so if you notice a significant drop-out in sound when both microphones are brought up in your mix, invert the phase on one of your signals.
6. Here's another two microphone technique: place a dynamic mic close to the speaker to pick up the dry guitar sound. To add room ambience, place a condenser (with a cardioid pattern. about ten feet from the front of the amp and about six feet high, pointed toward the middle of the speaker cabinet.
7. If the cab has two speakers, use a dynamic mic on one speaker and a condenser mic (set to cardioid. on the other. A large diaphragm dynamic is best, because it can pick up more bass than a small diaphragm dynamic. The condenser is for the highs. Place each mic as close to each speaker as possible, in order to get a dry sound which emphasizes the differences between highs and lows. However, you could wind up with phase cancellation; if the volume is quieter when both channels are panned center, reverse the phase of one of the mics. Often, when two mics are used, one is panned hard left, the other hard right.
8. Try recording the amp in different rooms and environments. A room with hard, reflective surfaces will naturally add some reverb to your sound as opposed to a room that’s carpeted and full of upholstered furniture. Again, there are no rules for getting the perfect sound. Looking for a crazy sound? Try placing the guitar amp face down on a hard, concrete floor (think an unfinished basement or garage., and then hang your microphone above the back of the amp near the ceiling. Weird? Yes. Distinct? Very. Have fun, and keep experimenting.
Musician's Friend carries a huge assortment of recording microphones. Here are some additional models to consider that get high marks for use in guitar-recording applications:
Large diaphragm condenser mics: Warm Audio WA-87 Vintage-Style Condenser Microphone; Aston Microphones Spirit Multi-Pattern Condenser Microphone