Acoustic recording techniques to get you started
A well-produced acoustic guitar is one of recorded music’s greatest treats. While many acoustics do come with pickups built in so they can be played through an amplifier or into a desk or DAW, the true beauty of an acoustic guitar comes in its unplugged, stripped back nature. Steel or nylon strings, causing air to reverberate around a big wooden body; it’s so simple, yet when done properly the results can be breathtaking.
If you’re new to recording, particularly recording acoustic instruments, then there are few things you should know which will help you achieve some amazing tones. For starters, recording an acoustic guitar is an entirely different experience to recording an electric. Yes, there are microphones involved (unless you play directly into a DAW) and you will have to have some understanding of room ambience, but whereas electric guitars and amplifiers can be tweaked endlessly to suit a room or particular sound, recording an acoustic guitar requires a bit more care and attention.
With that in mind, let’s look at some of the basic techniques involved in recording acoustic guitar at home. As with any recording, experimentation and trial and error is part of the fun but the following theories will at least point you in the right direction to get some great sounding results.
First and foremost, you’ll want to make sure your guitar is fully set up and ready for recording, ideally in advance of the actual planned session. As with any performance tool, be it a guitar or a car, regular maintenance is essential to ensure it’s operating at its fullest potential. A new set of strings, installed 24 hours earlier, will make a world of difference to the instrument’s sound, while checks for any fret or string buzzing will remove potentially nasty surprises from your recording. Steel strung acoustic guitars in particular have a nasty habit of producing a high pitched squeaking sound as your fretting fingers move across the fretboard. This particular sound is nigh on impossible to remove afterwards in the mix so a dab of GHS Fast Fret to lubricate the strings will pay off in the run long.
Fret buzz can be slightly more tricky to deal with on an acoustic guitar, but not impossible. However, if the buzzing is noticeable to you, it’ll certainly be noticeable to your listeners so it’s well worth having a guitar tech cast their eye over the guitar prior to recording.
Room choice and setup
Assuming the guitar is in fine fettle, we can take a look at the space in which we’ll be recording. There are no hard and fast rules here; for a big, warm open sound with plenty of natural reverb, find a good sized room without too many hard surfaces in it. Hard surfaces, like wooden floors or large mirrors, can result in the sound waves produced by the guitar bouncing around too much which can confuse your microphones and cause unwanted frequencies clogging up your mix. We go into more detail about acoustic treatment here. Sofas, cushions, even duvets dotted around the room can help, although don’t get too comfy as there’s work to be done!
If, on the other hand, you’re looking for something more intimate, perhaps for a singer/songwriter approach, a smaller room will help achieve that but the same principles around sound deflection stand true here.
Once you’ve decided on the right room, try playing the guitar in different locations; at the centre of the room, near the corners, facing different ways. It’s all fair game as you try and find that perfect sound, and remember – whatever you hear will be picked up by the microphone so it’s important to rule out any areas where the sound is dead and lifeless, if nothing else.
Mic choice and placement
With the guitar all set up, and the room chosen and laid out how you want it, we can start examining the different microphone techniques to help you get the sound you’re looking for. As outlined above, there are no rules here – if it sounds good, it is good – but there are certain things which top recording artists and producers come back to which are worthy of your attention.
When recording acoustic guitar, it is almost always preferable to use a condenser microphone. Condensers are generally better at picking up the subtle changes in dynamics in acoustic guitar playing than other types of microphones, which can make the end result a much more accurate representation of what was recorded. It’s possible to to get some great sounds using just one microphone, but for the best results we’d definitely recommend using two condensers.
Without getting too deep into the technical side of sound production, your acoustic guitar will tend to produce fuller, bass-heavy sounds nearer the headstock side of the soundhole, and more treble-orientated sounds at the bridge side. Generally, you’ll want to choose one of the sides and have that as your ‘main’ sound. A word of warning though; pointing your main mic directly over the soundhole will result in an oversaturated low-end sound which can be hard to rectify at the mixing stage.
In terms of which combination of microphones to use, many recording engineers advise using small diaphragm condensers close to the guitar’s body as they are able to pick up tiny transients better than those with larger diaphragms. However, conversely, a large diaphragm is a superb choice for placing slightly further away from the body to pick up a bit of room ambience. You’ll need to be aware of phase cancellation here, which is essentially where the same sound wave hits the different microphones at slightly different times causing the recorded sound to be, if not completely cancelled, then certainly noticeably affected.
For more information on this you should read up on the ‘3 to 1 ratio’ which is a way of combatting the nasty side effects of phase cancellation. There’s a great article here if you want to learn more.
You can experiment with different microphone placements, but always do it with the aim of finding the perfect spot. Headphones are your friend here, so make sure you have an extra-long headphone cable extender so your forays around the recording space aren’t cut short prematurely. The same rings true with a single mic setup – spend the time finding that perfect spot where the sound is rich and balanced, both to your naked ear and also through headphones. You should, however, also keep in mind that the performer will need to be able to play the instrument without worrying about hitting a mic during the perfect take. It’s a balancing act but one you’ll definitely overcome with a bit of patience.
Dawsons has a great range of short and wide diaphragm condenser microphones to suit the needs of anyone recording acoustic guitar at home. The excellent Shure PGA181 is made precisely for acoustic instrument recording, and is small enough that it won’t interfere with your performance. At the higher end of the price range, you may consider a two-mic combination consisting of the Sontronics STC1S small diaphragm condensers, which come in a pair, or using one of those in conjunction with a larger diaphragm model like the SE Electronics SE4400A to achieve a wonderfully balanced, accurate representation of your desired sound.
Home recording is loads of fun, and with a little bit of preparation you can achieve some amazing results. Good luck!