Ah the sweet sound of the acoustic guitar. Who doesn't like a punchy and driving acoustic rhythm guitar, or a lazy chordal strum to accent a singer's elaborate lyrics. In this premium tutorial I'll go through the steps needed for a nice sounding guitar production. You will learn how to use different microphone positions to get a different sound, overdubbing or repairing a badly recorded guitar track as well as a plethora of mixing tricks needed to get a great sounding acoustic guitar track up and running.
There are a whole lot of different positions that you can use to mike up an acoustic guitar, and all of them sound different. Without going into too much of what I've already said before in my Basix tutorial: How to Record the Acoustic Guitar I will stress the importance of experimenting with the different positions of your microphones. The difference in sound when recorded at the 12th fret or the 1st fret is incredible. The 12th fret is usually regarded as the sweet spot whereas a 1st fret position will pick up a sound that's predominant in high frequencies with all the intricacies of the strings as well.
Let's compare the two.
Guitar recorded with a condenser on the 12th fret
The 12th fret is a nice sweet spot to aim for when looking for a quick and dirty acoustic guitar recording. It's an easy starting point and is usually a good bet since it has a full more brilliant sound.
Guitar recorded with a condenser on the 1st fret
Notice how jangly and, for lack of a better word, stringy, this recording is. It wouldn't really work on its own since it lacks many of the fundamentals that make up an acoustic guitar sound. But it might be usable in conjunction with something else. By recording the guitar and overdubbing the same part with two different microphone techniques you can get a much different sound than if you would resort to artificial double tracking or recording with two microphones at the same time. So if we use these two techniques and overdub the 1st fret position with the 12th fret position we get something completely different.
My timing is a bit off since I didn't have a click track on, but the sound speaks for itself. I panned each of them about a quarter off-center so it would be easier to hear the difference in sound.
Cutting Out Boominess
If you end up recording too close to the soundhole you end up with a boomy sound. It's a common mistake to think that that's where the best sound of the acoustic guitar comes from. Even though it's true that the bulk of the sound of the acoustic comes from within the body of the guitar, and the soundhole acting as an escape for those sound-waves it's definitely not the most ideal place to position a microphone. However, if you end up recording an acoustic at the soundhole and you're struggling with the boomy low end that accompanies it then a quick EQ fix might be in order.
Listen to the same chord progression we've been listening to but recorded at the sound-hole.
That's a very boomy, and in my book, quite a useless sound. But we can still fix it with EQ. By taking a quick snap-shot of the EQ spectrum of the guitar we can see how dominant it is in the lower mids.
By taking a wide scoop out of the lower mids we essentially reduce the amount of boom we let through, repairing the guitar sound if you will. I've also added a subtle shelving cut at the bass frequencies since even though the problem with boominess is around 200 Hz we might want to reduce the bass a little bit as well.
Listen to how we've managed to repair our way too boomy acoustic guitar sound with only a few EQ tricks.
Line In Sound
If your acoustic guitar has a line-in plug that enables you to plug it into a recording interface or mixer then you have an even more varied sound at your disposal. However, the pickup that resides inside your acoustic guitar does have a very specific sound, and can sound very brittle and thin. Not to say that this particular sound can't be used, it most definitely can, but those who expect their pickup to accurately reflect the sound of their acoustic guitar will be sorely disappointed.
Combining both line and mic
Those who like the sound of their line-in sound but want to have the added benefit of the more natural miked up acoustic guitar sound can opt to record both at the same time. This will result in two tracks of a very different acoustic guitar sound that is usable in many ways. Instead of using two microphones on the guitar you might opt to use one microphone and a line-in to mix together. This might result in a less natural sound than using purely microphone techniques but if you like the sound, or just have one microphone lying around then it's a good idea to try it out.
Lining up the phase
When you record an acoustic guitar with both line-in and a microphone you might have some phase issues. Basically, the sound that's being captured by the line-in jack transmits faster than the sound waves that the microphone is picking up. This is not always the case, and depending on how close you mike up your guitar you might not have to deal with any phase issues. But the farther away your guitar is to the microphone the bigger the chance of phase problems. There are a few tricks that you can use to fix these phase problems.
Zoom in – You can zoom into the wave forms and see if the sound-waves are lined up or are out of phase from one another. You can move either waveform so that the crests and troughs line up better. It's not good if they mirror each other so line either one up to fix the problem.
Invert the waveform – Most DAWs have a way for you to invert the phase of a waveform. Choose either one and invert the phase so that they line up better.
Usually, you will find that your guitar sounds thicker and more powerful in the lower frequencies. If you invert the phase of one waveform and the body of the guitar suddenly comes through chances are you were having some serious phase issues.
Mixing the Acoustic Guitar
You may have noticed that even though I did record my guitar at the “sweet spot”, there are definitely a few things that could sound better. That's where mixing comes into play. Regardless of how well something might sound it will probably be tweaked a little during the mixing stage. Let's see what we can do to make our little chord progression sound a little better.
I like to start off with repairing and filtering unwanted frequencies out before I do anything else. Using an equalizer I've filtered out the lowest end that would otherwise be cluttering up the low end spectrum. With a few surgical cuts I've cut out the boomiest frequencies at 200 Hz, the jangly “cheap” sound at around 800 Hz and the nasally tin sound at 1.2 kHz.
This results in a little more pleasing guitar sound that you can hear here:
I actually want to try and have the compressor breathe a little and be noticeable. The compressor is averaging a 8 – 10 dB of gain reduction with a ratio of 5.6 : 1. I don't want the compressor to chomp down immediately so I set the attack at medium, allowing the transients to come through. The release is set pretty fast but the compressor never really stops working, with the compressor constantly compressing at least half a dB. This might seem like a big no-no since it sounds a little squashed, but it's just an example in what you can make a compressor do.
Now I want to draw out the character of the acoustic guitar with some tasteful EQ boosts. I wanted a little more presence and brilliance in the strings and along the way I thought it could use a little more cuts in the cheap-o 800 Hz. With just a little bit of boosts in the right places I've managed to enhance the guitar sound way beyond what I had when I started.
Now that we've got the sound we want down pat, it's time to put it where we want it. Reverb can play an integral part in an acoustic guitar part, making it sound distant and lonely or like somebody is playing it beside you in the room.
With just a small addition of some room reverb we can make a home-y acoustic guitar, reminiscent of Beck's Sea Change album in just a few easy steps. The E and A chords actually mirror the opening track “The Golden Age” so I must have subconsciously wanted to recreate something similar.
The relationship between the dry guitar sound and the reverb dictates how distant or close the guitar sound will be. If you lower the actual volume of the guitar track but push up the volume of the reverb you can end up with a guitar track that sounds very far away.
Listen to the example below which has a much higher volume of the actual reverb than the guitar. Notice how it makes you perceive the guitar as farther away.
Let's leave the small room sound on for now and try some different techniques to make it sound a little less generic. There are a ton of ways to use modulation effects to enhance a normal sounding track, it's all about context and what you ultimately want out of the track. If it's just a typical rhythm guitar that should just hang low in the background a super crazy phaser effect won't help with that. However, just like with the hall reverb example above, you can use modulation effects to push things into the background without just lowering the volume or adding too much extra space with reverb.
Hear how the guitar sounds more distant without necessarily having to create a big space with reverb around it? With just a touch of chorus instad of reverb on a auxiliary track you can achieve the same effect. Low rate and depth seems to dull the sound a little bit and the inherent delay that's in a chorus effect creates the sense of space that seems to push the guitarsound away.
Using the Acoustic Guitar as an Electric
I'm really fond of using my acoustic guitar in lieu of an electric. I plug my acoustic guitar into the board and use the amp simulators and other effects to really create a different sound than would have been possible if I had miked up the acoustic. The line-in sound almost plays a different role when you use it as an electric. It doesn't sound as metallic and toppy when you put it through your amp simulator or effects. It works wonder if you are playing rhythm especially. Due to the nature of the acoustic guitar it gives the rhythm section a fuller and thicker sound. Maybe I've just gotten used to playing my acoustic guitar more than my electric but I definitely try to use it much more often than I do my electric.
Even if you already have a great sounding miked up acoustic guitar you can still try putting it through an amp simulator if you want a more electric, amped up sound. A simple simulator changes the sound completely and it might be a great way to add variety to your tracks. Listen to our already mixed acoustic track and how it changes we I insert an amp simulator before all the processing I've done so far.
Changes completely doesn't it?
The acoustic guitar has a lot to offer. Whether you are using it as a foundation instrument strumming away in the background or as a lead acoustic guitar solo the range of sound you can get from an acoustic guitar are amazing. Don't think purely of it as an acoustic instrument that should be treated nice and subtly with only some compression, EQ and reverb. Try using all sorts of processors on it and see if you can come up with something new. Throughout this tutorial we've touched upon many of the more essential techniques you need to be aware when dealing with the acoustic guitar and I hope that you have a better understanding of the possibilities it can give you.