Recording Electric Guitar

The fundamentals of a 22-fret guitar cover E2 to D6 (82 Hz to 1174 Hz). The overtones extend much higher.
As nearly all electric guitars operate at high impedance, frequencies above 5 kHz tend to get attenuated by the ¼" cable between guitar and amp. Most guitar speakers have an upper limit below 5 or 6 kHz.
Smaller amps have an accentuated response in the 4 to 5 kHz range, which helps the amp produce a clear and clean tone.
The amplifier is as important as the guitar. Both are required to generate the electric guitar's tone.

Dynamics and Condensers

Dynamic mics were used by British engineers in the 60s. They produce a mid-ranged, 'fat' tone due to the dynamic mic's insensitivity to high frequencies.
Condenser mics were used by most American engineers during the same time. The additional high frequencies make the sound less round and more incisive.
Cardioid mics will reject room sound when close miking a guitar cab.
A cardioid dynamic produces a full tone without picking up extraneous amplifier noise.
The presence peak inherent in some mic designs can work effectively on guitar cabs.
A miking distance of 2″ to 1′ is normally sufficient when you require separation from other sound. Miking closer than 4″ makes the cone placement more critical.

Cone Positioning

Dust cap	Trebly sound with lots of bite
Mid cone	Fewer high frequencies, slightly warmer and fatter
Outer edge	Significantly fewer high frequencies, much warmer and fatter

Cabs with more than one speaker tend to have one cone which is better than the others. Listen carefully before choosing which to mic up.

Bass Lift

Mics with a bass lift switch are useful in counteracting the proximity effect or obtaining a different tone. Experiment with the switch on and off. Some styles (e.g. jazz) require a bass-heavy tone, whereas others (e.g. funk) need the bass end to be attenuated.

The Sweet Spot

The sweet spot (or hot spot) is the point at which the balance between direct and reverberant sound sounds best to you. It is a matter of personal judgement where it is. Moving the mic(s) around the room will alter the balance of direct and reverberant sound. Treating the room with different acoustical materials (drapes, carpets etc.) will change the recorded tone too.

Using Two Mics

Use two mics on one amp to combine the desired characteristics of both.
The classic example is to use a dynamic close mic (e.g. an SM57) and a condenser ambient mic (e.g. a C1000S). This can cause major phase problems, so take great care in positioning the ambient mic.
This can also be faked with artificial reverb.
Guitar sounds unnatural when listened to completely dry. Adding a little reverb can give you a much better idea of how the final product will sound.
One way of minimising phase problems with two mics is to use them as a coincident pair, even when they are completely different types of mic.

Miking up the strings of an electric guitar can be effective. This adds a high-frequency zing to the recorded tone, and is best picked up by a small diaphragm condenser. The guitarist will have to be in a different room to their amplifier for this to be achieved with the minimum spill.

Open and Closed Back Cabs

Most guitar cabs are of an open-back design. They are designed to project both forwards and backwards.
Some cabs have a closed-back design. They reflect all sound forwards.
Open-back cabs can benefit from being miked from the rear as well as the front. Either mic can be used for the main tone, with the other blended in.
Phase issues play a major part in the placement of these mics.

Alternatives to Amplifiers

Using a DI box to record directly into the desk produces a very clean tone, and eliminates any spill problems. The tone is very bright as it has not been filtered by the speaker.
A combination of DI and miked signals can combine the best characteristics of both. These can be combined onto one track or recorded onto separate tracks. Phase issues can be problematic, as there is a small delay between the DI signal and the mic signal.
Some engineers record the guitar using a DI box; once the session is over they then run the recorded signal through an amplifier and re-record the results. This allows them time to experiment after the (expensive) session player has left.
Speaker simulators can be used in the studio. An amp is fed into the simulator, which allows a balanced output to be fed directly into the desk with no need for a speaker cab or microphones.
Amplifier simulators replace both the amp and the cab. They allow the guitarist to plug directly into the desk with very realistic results.

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