Whether your acoustic guitar track is going to be at the forefront of the song such as in an acoustic vocal demo or simply the rhythm section of a full on rock track, properly mixing your guitar not only ensures that it will sound nice and balanced on its own, but also helps it blend well with the rest of your project. Some people might assume that because the acoustic guitar is a pretty straight forward instrument that mixing it should be just as easy. Too bad it’s not though. A common misconception that many newer home studio producers tend to make is that they are always searching for that magic EQ preset that works every time and as anyone experienced with mixing can tell you, that can’t be farther from the truth. The thing is that you will probably never use the same EQ settings from song to song, even if the same exact instruments and mics are being used. Everything from the key of the song to the style that you’re playing or even the pick used will give the track its own unique set of EQing priorities. And while I can simply give you any magic numbers, I can do the next best thing; teach you how to think about and approach your acoustic guitar track to give you a basic idea of how to go about EQing so that you will be able to apply it every time for most situations. The first thing though, is we have to find out a little more about the frequencies we’re going to deal with when EQing an acoustic guitar.
The Low End
One of the most common problems that can happen with an acoustic guitar mix is that it can sometimes end up sounding either a bit too thin and lifeless or way too boomy and deep. Ideally, we want our acoustic guitar to sound as full, rich and natural in tone as possible. What many might not realize is that the acoustic guitar has bass to it – a whole lot of it actually – and one of the biggest causes of headaches while mixing is dealing with too much low end frequency. If you’re curious about how much bass we’re talking about exactly, record your acoustic and then add a filter to cut out everything above the 100 Hz mark, leaving only the low end of your track. I’m sure you’ll be surprised at just how deep of a rumble is hidden among the entire tone of the acoustic. So, maybe use a High Pass Filter to cut out the low end? Well, like many other things in the world of mixing – that depends. Certain songs such as those with simply a guitar and voice might need a good dose of that bass in order to have the track feel nice and full but most of the time, I can tell you it’s a better idea to just get rid of it, especially if the acoustic guitar isn’t the prominent instrument. The amount of bass that should be rolled off depends on how the track sounds; sometimes I will only need to get rid of frequencies below the 200 Hz mark while other times it might be as high as 450 Hz depending on how it mixes with the rest of the song. But as a rule of thumb, you will never need anything below the 100 Hz mark (since to the human ear anything below that comes off as more of a rumble that you can feel rather than the part of the bass you can hear) so make sure that at the very least you get rid of that much.
The Low Mids
Alright, so now that we know that the extreme low end of an acoustic track is best removed, or at least toned down, we can move on to our money maker, the all-important low mids! This is where the body of the guitar sits as well as most of its tone so it’s important that we make sure to give it all the attention it deserves, and seeing as how it’s the most important, it’s also the trickiest to get down. More often than not, even after employing a high pass filter for that low end, your track might still be a bit too bass heavy unless you but out certain portion of these low mids. At this point, the question you should be asking yourself is should you dramatically remove a small group of these low mid frequencies or should you rather slightly turn down a large range of them? Well, by now you should have figured out the inevitable answer; it depends, but I can tell you now that it’s going to take a bit of trial and error along with a decent dose of experimentation. Let’s say for example your guitar has a bit too much attack at the 200 Hz mark. You can either make a huge cut at that specific section or try slightly lowering the range of frequencies around this point, let’s say between 150 and 350 Hz. Depending on the EQ necessities of the rest of your mix, one of the two options will probably sound better. Slightly lowering a big range will let the acoustic track retain its full bodied sound while cutting out certain frequencies completely will help with balancing the track with the rest of the mix. Again, depending on your situation, one might be better than the other, but generally speaking, I find that it often sounds more musical to turn down frequencies instead of completely getting rid of them.
Also, we still have to make sure that high pass filter we’re using for the low end is taken into account when dealing with the low mids. Let’s say you had it set to roll off at 150 Hz but it was a bit too bass heavy and then moved it up to 200 Hz but the track became too flat and thin. And to make things worse, you can’t seem to find a satisfactory midpoint between the two. This is a common problem but not as difficult to fix as it may seem. Using out example, leave the high pass filter at 150 Hz or in your case the highest point you can get the filter at without sounding too thin. It should still be a bit boomy though. Alright, after that, find the midpoint between the too deep (150 Hz) and too thin (200 Hz) frequency range, which in this example is about 175 Hz, then simply cut around this point. By cutting out a small portion above the low point of the filter roll off, you can get rid of just enough bass without getting rid of that important low mid.
Alright, now that the hard part is done, you can add some extra natural sounding flair to your acoustic guitar by messing around with the high frequency range. Try adding a high frequency shelf in order to give your track some crispness, but remember to use it in tiny increments as it is easy to overdo it and add too much gain. A high shelf is more of a fine tuning tool used to increase a listener’s satisfaction with a track rather than actually doing any real sort of equalization, just in case you’re wondering. Just remember, treat it like salt - just enough and its so much better than before but even just a slight bit too much and its entirely runined - but the good thing about working with digital is that good ol' undo button. Alright, well, that does it for today but remember to head back here tomorrow for much, much more.