Recording guitars is one of the most satisfying parts of the recording process, and there are endless tonal possibilities. Factor in different guitars, amplifiers, stompboxes and effects, the fascinating world of modeling, and the options of microphone choice and placement and the possibilities are literally endless!
I've written this cursory guide to help you get the best sonic results you can. I want to stress that this is an art form, and while there are certainly principles to follow, the best part is breaking the mold and being creative.
Set It Up
Make sure that all equipment to be used for the recording is serviced and working efficiently. Set up all the guitars, tune and intonate. Fresh strings, fresh tubes, whatever your gear needs, listen to it!
This will vary depending upon the tone desired, the guitarists' rig design, the player, and the equipment available. The most tried-and-true mic to use for electric guitars is the Shure SM57, and it has been the tone of COUNTLESS records. Other similar dynamic mics, and also good choices, are the Sennheiser e906 or 421, the Audix i5, or the Shure SM7.
Many are fine with a single dynamic for electric guitar, and some like condenser mics for recording cleaner tones, and/or when paired with a dynamic. The two different mics can complement one another sonically.
Ribbon microphones are quite at home recording electric guitars, but due to their high cost and fragility they are rarely found outside of professional studios. Many also prefer the combination of a dynamic and a ribbon.
Get It Right At The Source
Getting tone right at the source will make the mix fall together perfectly. Most of the time all that's needed to record a great guitar track is proper microphone choice and placement (and of course a good guitarist!). Various microphone positions lend themselves to different sounds, and experimenting with them variously and often will result in a variety of choices for the sonic palette.
Recorded guitar tracks with too much gain will sound thin and mushy in the mix. Even for heavy guitar parts, dialing in a lot less gain on the amp will lead to the huge-sounding wall of guitars everyone is looking for.
Check Your Levels!
This applies not only to guitar but everything that's going into your recorder (or DAW). Proper gain-staging is critical to good recorded tracks, and distortion (the bad kind) can ruin an otherwise glorious take.
Get A DI Track
It's good practice to record a clean DI track along with the amplifiers. This allows options for re-amping later, or a simulation plug-in can be instantiated.
I prefer to track amps with no reverb. Some prefer to record guitar amplifiers in a very confined space, such as an isolation booth or something similar, but I prefer to just close mic them in a good room. The close micing won't really pick up any room sound anyway, and it tends to not sound as "boxy".
Reverb can always be added in to taste during mixdown, as the balance of the song may have changed. This is a stylistic choice.
This is when the real fun begins. Throw those faders up and have at it! One thing I always find when mixing guitars is that they can be pulled fairly low in fader position and still be as clear and present as ever. This again comes back to the vocal/guitar/snare balance that is critical to modern recordings.
Use The MONO Button!
I feel like this should be said first. The mono button is vital to a good, balanced mix. Equalization, level imbalances, and phase issues are very obvious in mono. Mixing and referencing your mix in mono and back to stereo will lead to a much better-sounding mix overall, not to mention that many public playback systems still operate in mono.
These are three of the most important elements to the mix, and they all compete for space and frequency. Getting this balance is crucial to a good mix. Many times I find that the guitars can be pulled farther down than one would think, and they will still be powerful and present while not overpowering the vocals.
This can be one of the biggest stylistic options, but generally guitars sound better on the outer edges of the stereo spectrum. Much creativity can be had by manipulating panning positions during different parts of the song. This can lend an openness or expansive feeling to the track and really make the rocking parts hit home.
It's important to cut the bottom out of electric guitar tracks. Most microphones used to record guitars don't get much below 100Hz anyway (nor do guitar speakers), but in the mix it's good practice to just take this out anyway. There can be rumble, room noise, etc. The result will be more articulate tracks and increased headroom on the master buss.
Just as important is the low-pass filter, which will cut out everything that's not needed on the high frequency part of the spectrum. Although some harmonics do reside here, mostly it is just harshness and "fizz" that is detrimental to the overall mix. Again, most guitar speakers don't put out anything above 5-6kHz but it's still good practice to use the shelving filters.
Most of the time, low-mids really smear a recording. There are no magic frequencies, but removing some around 200-350Hz in guitars really takes away the mud. Sweep around to find it specifically. This is also true for most instruments.
Another tool is the option of automation or side-chaining your guitars to your vocal track. For automation, you can pull the guitars by maybe -1.5/3.0dB when vocals are present and push them back up when not. This makes the vocals more clear and the mix better overall.
As for side-chaining, you just set a compressor from the vocal to control your guitars. The same concept as above but you don't have to automate the envelope.
I'm a lifelong guitarist, so of course recording guitars is one of my favorite parts of the process. As mentioned this is a cursory overview of some of the important concepts of recording guitar. Learn the rules, break every one of them, and go lay down some great guitar tracks!
About the author: Brandon Stoner runs Audio Ecstasy Productions out of Los Angeles, CA specializing in guitar and backline tech for touring, custom stompbox and cable design for stage and studio, audio engineering, and many other audio and guitar-related services.