Tech Tip:How To Mike A Guitar Amp In The Recording Studio
There are several methods that are used a lot in miking guitar amps in the recording studio. Each yields a different sound, so find the one that's appropriate for your music. Use these suggestions as starting points, then adjust the mic a bit until you get the tone you're seeking.
1) Place a dynamic mic pointed at the center of the amp's speaker cone, up against the grillecloth. If the cab 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 dislike pointing the mic at the center of the cone, and prefer to point it about a third of the way toward the rim of the speaker.
2) Point the mic at or near the center of the speaker cone, a short distance away. Some of the room ambience will be mixed in with the amp tone. Experiment with various distances; try 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.
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.
4) Try miking at various distances from the amp, 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. You might also pick up some sounds from the environment, such as cars and dogs.
5) If you have two mics and an open-back amp, mic 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. Distance 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.
6) Another two-mic technique: place a dynamic mic close to the speaker to pick up the dry guitar sound. To add room ambience, place a condenser (in 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) Put the amp in different rooms. A concrete room will have a longer reverb time than a carpeted room. One of our techs likes to place the guitar amp face down on the floor in a concrete laundry room, hanging the mic above the back of the amp near the ceiling. Have fun, and keep experimenting.
Musician's Friend carries many recording mics, including these, which are especially recommended for miking guitar amps:
- Large diaphragm dynamic: Sennheiser MD421; Electro-Voice RE20
- Condenser: Rode NT1 CAD Equitek E350
- Large diaphragm condenser: AKG 414