Recording an acoustic guitar can be accomplished in a number of ways because there are so many variables. I’m going to show you how I recorded my acoustic guitar for this audio example. I’m also going to show you another way in which you can record electric guitars and basses called DI (Direct Injection).
It’s imperative that you take certain precautions before recording guitar to get the best possible sound from the guitar as well as the recording. Knowing what you need to achieve is half the battle and you should always have a plan before you start recording. The first step is by clearing a space and finding a good room that compliments the guitar. You can always change the tone of the guitar in post-production but it’s always best to achieve this in the real world as it saves time and ensures you’re working with the best quality recording that you can achieve. Ensure that your guitar is in tune and that nothing that the player is wearing compromises the recording. It seems relatively logical but it is a very real situation that a lot of producers fall trap too. Finally, make sure the player is well rehearsed and don’t stop recording until you’ve sure you’ve got the take you are after, there’s no such thing as a ‘one take wonder’. The best results are always achieved by working with the natural sound of the instrument rather than trying to make it something it isn’t. Mic choice and placement always work better than EQ. With that said, let’s begin.
When recording guitar, whether it’s the subtle harmonies of strumming chords or the intricacy of finger picking, I would advise using a small-diaphragm capacitor mic (pointed at the 12th fret) for its greater high-frequency accuracy, and one with an omni polar pattern for a more transparent sound than can be achieved using a cardioid. The omni polar pattern won’t just capture the pure tone of the guitar but any natural reverb that the room has to offer. Another mono mic position would be over the player’s shoulder. It might sound strange, but having the guitar of the shoulder and angled down towards the body of the guitar produces a very natural and bright sounding tone. It typically doesn’t work well if you are trying to capture the lower frequencies of the guitar but you could always add a second mic pointed towards the body (from the ground) and blend the two together.
Using a stereo miking array to capture the guitar is also straight forward providing you know what you’ll be doing with the recording afterwards. Using an XY array (cardioid) pointed at the 12th fret and 300mm – 400mm away (Same distance as the body of the guitar) and you will be in a good position to record. The disadvantage of this array is that the guitar won’t sound very wide but will be much easier to fold back into mono if that was your intention. For a wider sounding stereo array, I would suggest either an AB (Spaced pair) or an MS (Mid-Side) array.
Using the AB array to the fullest would be to wear headphones whilst the guitarist plays and position the mics by ear. As you move with the mics in your hand, you will hear how the guitar will sound and choose the position best suiting you. A good starting point is to have mic A pointed at the body of the guitar but not aiming at the sound hole as that would sound uneven when mic B is pointing at the 12th fret of the guitar to pick up the higher frequencies.
Here I have inserted two sound clips that demonstrate the proximity effect and a weak signal when a mic is too far away. As you’ll be able to hear, the proximity effect adds bass and the distance recording is very weak and lacks any punch to it.
Direct Injection of Instruments
DI’s are frequently used to connect an electric guitar or electric bass to a mixing console’s microphone input. The DI performs level matching, balancing, and either active buffering or passive impedance matching/impedance bridging to minimize noise, distortion, and ground loops.
This is a really simple and easy way to record any electric guitar or bass guitar. Through DI, you need not worry about phase cancellation and if you are able to to split the signal so that you capture the DI and are connected to a bass amp which you happen to be recording, you can blend the two together with minimal effort.