This month I'd like to re-cap a topic that is always relevant: Recording acoustic guitars. Last month I alluded to a session where I had a ton of electric and acoustic guitars to mix plus vocals. This time we'll keep it to just the acoustic guitars.

As always, I'm going to go through obligatory questions:

1. What sound are we looking for?
2. What is the sound source (nylon, steel string, 12 string, with or without internal pick up)

This is the thought process I use to determine not only how I'm going to mic the source, but capture the tone I want.

What sound are you looking for?
This is very important because if you just set up some mics and record with no regard for the tone you're getting, it's going to be extremely difficult to change that tone later, especially if the tone you recorded isn't what you wanted in the first place. Not to mention phase problems, and other little demons like boominess, and pumping that can happen if you're using a compressor.

Example:
Do I want more of a picked sound? Or a smoother, almost brushed strumming sound? Do I record a finger picking tone with, or without the fingernail sound? Do I want a big "Right out of the sound hole" tone? Or maybe, a brighter kind of string tone?

So you can see that there's much to think about before we even get to eq's, and mic pre's and the like. Thinking ahead can save you from many troubles down the road. Because in reality, saying "I'll fix it in the mix" is almost like saying "I'm going to put band-aids where stitches should go". I try to follow an acronym that is affectionately known as "The Six P's" Prior-Preparation-Prevents-Painfully-Poor-Performance. Take the time to get the sound right before you record.

For me, there are four main areas to close mic an acoustic guitar. Starting about 6-12 inches from the guitar: 1) over the sound hole, 2) over the twelfth fret, 3) back by the bridge, and 4) by the nut looking down the neck. Two of these are the norms and the other two are more unorthodox. Keep in mind that a big lush acoustic guitar sound may not always be what you want or need for a project. So, while I'll go through a couple of pretty typical examples, you may try something quite exotic that sounds great. Be proud of that. (Then, email me the technique so that I can use it!) Many engineers don't even like to share their mic techniques, and we all have our favorites.

Have patience with me, as there's so much that matters even before you hit the red button…

Microphones:
The choice of mic will have a great influence on the recorded sound of guitar. For acoustic guitars I would suggest a condenser mic with a cardiod mic pattern. They have much more sensitivity than a dynamic mic. This means that it will pick up much more of the little nuances of the guitar. Besides just choosing a condenser mic, find one that's right for the sound you're trying to achieve.

The line in the sand between small and large condenser mics seems to be smaller than a 1" capsule is small, equal to or larger than 1" would be a large capsule condenser mic. Smaller condenser mics will produce a more detailed and less boomy kind of sound. These small capsules are great for a Pop or bright Country guitar type of sound. Typically a mic like a Neumann KM-184 has a great sound and a roll off at about 200Hz that minimizes the boominess an acoustic guitar can have. If you've ever recorded an acoustic with the mic pointed right into the soundhole at about 4", you know the boominess I speak of. And it's pretty impossible to get rid of later without killing the tone of the instruments characteristics elsewhere in the frequency spectrum.

A larger capsule condenser mic will give you a warmer tone while having great clarity and depth. This would be great for mic'ing an acoustic Jazz guitar, or in any situation where you would want a smooth, warm guitar tone. So deciding what style of guitar you're recording, the player's dynamics and intensity, the actual guitar itself, and the room acoustics must all be considered when recording acoustic guitars.

A quick note on the guitar itself: Use a guitar that is going to record well. At a minimum have brand new strings on the guitar, at maximum, make sure the frets have been worked on, neck tension rod adjusted, etc.

Let's get to mic placement. As mentioned before, there are two typical ways to mic an acoustic. Take a condenser mic, place it between 6-12 inches from the sound hole pointed fairly towards the end of the fretboard. It's totally OK to move around the guitar and put your ear where you think the sweet spots are. Obviously not too close, and don't have the guitar player strumming like a madman. But you'll quickly hear the better spots from the worse spots. If it sounds good to your ear, it's pretty much going to sound right to a mic. Place the mic in that spot. It's important to realize that an inch or two can make a huge difference in the recorded sound, so take your time. If you're recording this yourself in a home studio, you can go ahead and record as many practice takes as you like, moving the mic around until you get the sound that you want. This mic position will get you the biggest sound out of an acoustic guitar. Hear an example.

The second spot is over the twelfth fret. This has a more brilliant sound. You can try having the mic perpendicular to the guitar, or pointed slightly towards the sound hole. Hear an example.

The third spot is back by the bridge. This will get you a thin sound very much punctuated in the high end. This can sometimes be useful when you want to hear that there's an acoustic in the mix, more by the strumming string noise than the actual chord being played. Another method for getting that sound is to have an acoustic guitar with a cloth in-between the strings and the fretboard then just strum with the song. Recording this will give you that same effect. Hear an example.

Fourth is a down the neck shot. The mic is placed at the nut, facing down the neck towards the sound hole. This is also good for an exotic kind of sound. It's not the normal big acoustic sound by any means, but it can be used in a case where you might normally use an EQ filter to thin things out.Another option is stereo mic'ing, but watch out for phase problems. Hear an example.

Now that you've picked a mic, and a placement for it, now let's go for the EQ. Some engineers believe to never record with EQ, others believe in EQ'ing right from the start. I say do what the situation demands. Whether you EQ before or after, here are some hints… Pulling a couple of dB out at 100Hz, or 300 Hz can be a great low end filter to keep unwanted boom out of the sound. To put some sheen on the sound, put in a couple of dB's way up in the 9kHz range. To keep the guitars from fighting the vocals pulling a dB or two at 4.5kHz should help.

For a tighter sound, try a compressor with a compression ratio in-between 2:1 and 4:1. Be easy on the threshold though. You don't want to squeeze the life out of the guitar. Just use enough compression to handle transients. If you record with compression, and compress too hard, you're going to spend a lot of time trying to EQ life back into it; which is virtually impossible.

When using the built in pick-up of the guitar, like a piezo, try this: pull a little out of the 1.5kHz range. This can get rid of the more nasal mid range tone that piezos can sometimes have. Also perhaps a small bump at 200 Hz.

Following some of these ideas should get you in the ballpark for a good acoustic guitar sound. Experiment. Find out what works best for you.

And Have fun while you're at it!

Take care,
Phil

makintrax@philgates.com
http://www.philgates.com