Recording: Acoustic Guitar

    Recording acoustic guitar is a relatively simple thing to do, but for most guitarists the world of recording is seen as a bit of a dark art. In this article I will attempt to allay that myth and help you on the way to recording with confidence.

    The first thing to do is understand the different mic types and understand what they look like, so that you can work out what they are for. You don't have to be able to name them, just associate the design with the function. For this article I'll briefly explain the ones that follow in the main body.


The Mics

The condenser microphone is the main theme here, with two kinds being used here and variations on those two can be used in a large variety of applications. Both will require phantom power to operate, so make sure you have dedicated mic pre's or a recording interface with phantom +48V power. They are the Large Diaphragm condenser and the Small Diaphragm condenser, examples of which are pictured below (fig. 1).

              (fig.1) From left: Sennheiser MKH 40, small diaphragm, and AKG 414, large diaphragm mics

     The difference in the two is in directionality and "openness". The sheer area of the diaphram has a profound effect on the performance and tonality of the microphones. Large Diaphragm mics have a very natural, open sound stage, and are quite often omni directional. More expensive ones have multiple, switchable polar patterns (feel free to look them up on wikipedia), making them extra versatile. The size of the diaphragm makes them very sensitive to any air movement, making them  They can be used as close acoustic instrument mics and as ambient mics in controlled recording environments. Small diaphram mics are usually cardioid pattern, due to the orientation of the capsule in the device. Some have interchangeable capsules to facilitate various different usage scenarios.

Anyway...

The Method

     To start with I use a large diaphragm condenser, somewhere around one or two feet away; and if you can change it, set the pickup pettern set to a cardiod pattern. Point the mic towards the 12th fret, or at the point where the neck meets the body. As the mic is moved further away you will incorporate more of the room ambience into your sound, gathering all the natural echoes and reflections in the room. Move the position of the mic towards the sound hole and you will pick up more and more bass frequency, and nearer the neck will get less.  My personal favourite mic for this is the AKG 414 which, luckily for me, I have easy access to. A cheaper alternative would be an SE2200, which is a great sounding mic for the money.

     I couple that with a more directional small diaphram condenser, probably a bit closer than the large diaphram, but pointed somewhere just below the 12th fret of fingerboard so as to be pointing it at the guitar, but not at the sound hole. That should give you a more defined high midrange. Another option, using two of this kind of mic, preferably  a matched pair, would be to place them over the shoulder of the guitarist. This is likely to reproduce the sound of the guitar which the guitarist hears. My mics of choice for really nice sounds are the AKG 451 and Sennheiser MKH 40. Expensive I know... A cheaper alternative could be the AKG perception 170, or other mics by Rode and SE, which sound pretty good for the money.

     Further to that, if you have an electro acoustic with a pickup, you can plug that in and mix that in with the sound too. The piezo pickup in the bridge will usually help with outlining the attack of your playing, which can sometimes be lost on large diaphragm mics.

     With that three or four channel set-up you can really tweak your sound in your choice of DAW. It should give you enough frequency range to push and pull it around a mix too so that it sits just right.

Of course, everything Audio is a case of trial and error, and these are by no means hard and fast rules, but I hope that's been of some help, and sent you in somewhere near the right direction.

Charlie