Written by Dan Shaw, a producer and mix engineer with Sydney recording studio Enmore Audio.
Selecting the right microphone for any given guitar performance is key to obtaining an exceptional tone. Just like a guitar or an amp, each microphone will colour the sound with its own character, ranging in difference from the subtle, to the extreme. So, how do we make the right choice?
Different Microphone Styles
Having an understanding of the basic attributes of the three major microphone designs is essential to the appropriate coupling of mic and sound source.
A tried and tested selection for the guitar amplifier is a dynamic microphone. Dynamics can take a lot of punishment, so capturing a cranked up valve amp that’s pumping out a lot of decibels is handled well with this microphone type. Microphones like the Shure SM57 also have a substantial rolloff below 200hz, and a top end bump which makes their unique frequency response ideally suited to rock’n’roll guitars.
Condensers are typically less desired on guitar amp cabinets, owing to a typically flatter response, with a crispier top end, which can be a little too brittle for this particular sound. Condensers vary quite widely in quality though, so if you do have a few Neumann U87s at your disposal, rest assured they would sound lovely!
Ribbons are longtime favourites on the electric, as their frequency profile tends to soften harsher frequencies. Warm and lush, they can be just the thing if you’re looking for a big and bold guitar sound to fill the bottom end.
Acoustic guitars are, of course, a whole different kettle of fish. The transients peaks produced by an acoustic require a more sensitive treatment of the top end, and thus condensers are more appropriate than dynamics in this case. Ribbons have a higher noise floor than condensers and as such, can be somewhat problematic for capturing quiet sources. They do however, have a mysterious, “glassy” quality if you fish around for the right position and are well worth exploring for this application.
One Mic or More
Another worthy experiment is a multi mic approach when recording the electric or acoustic guitar. Often, engineers favour a method which utilises the best of two or more microphone types. For example, the combination of the full-bodied ribbon and a gutsy, mid-range focussed dynamic may yield a diverse range of tonal possibilities.
The acoustic has the extra dimension (or challenge) of being, well, acoustic. The sound will react differently to any given environment and the guitar itself offers up a variety of tonal colours, depending at which part of the body you aim the microphone. The neck sound is thin and toppy, the body sound is full and boomy. A carefully placed mic array which harnesses both of these characters may be integral in recording an acoustic sound that has equal helpings of bite and depth.
This information should be of interest to guitarists as well as budding recording engineers. Why? Thinking about your tone as a performer from the sound of your strings to the ears of the listener is crucial to becoming a more complete musician and an asset to any studio project you find yourself a part of. That extra know-how in dealing with microphones and their various applications can make the difference between simply recording an individual performance, and finding a unique character for the guitar in the final mix.