As I’ve watched some young engineers record acoustic guitars (or any acoustic instrument such as a mandolin, ukulele, etc), I’ve discovered that very little thought seems to go into this process. So I’ll briefly share some techniques that I personally use which will undoubtedly yield you some great results! These aren’t new or groundbreaking techniques by any means, but I’ve noticed that a shockingly large number of engineers do not get good captures when it comes to these instruments.
So here we go; let’s start with two quality small diaphragm condenser microphones. And no, they do NOT need to be a matched stereo pair. They don’t even need to be the same make or model of microphone! This is a very common misconception. Examples of the mics that I use for this application are the Audio Technica DR3700 (also known as the AT Pro37), the Audio Technica 2021 (very, very similar to the DR3700 and Pro 37), the Shure SM81, the Shure KSM141, the Neumann KM184, the Octava MK-012, and even the MXL 991. Now I understand that many of these mics are considered fairly high-dollar. But don’t fret, I’ve achieved good results with lesser mics many times. Just do your best with what you have! One of my favorite mic combos for this is the AT 2021 on the neck and the MXL 991 on the bridge, which are both under $100.00!
Now that we’ve got some ideas for which microphones to use, we need to address the ever-challenging issue of physical placement for the mics. This is also something that I see many, many engineers struggle with. So let’s take a look at the very popular X-Y coincident pair; I really hope you guys are familiar with this technique. If you aren’t, do some research on this because it is easily one of the most used and effective miking techniques ever invented. By creating a 90 degree angle with the two mic capsules, you virtually eliminate phasing issues and allow yourself a capture that is a more accurate and “complete” representation of the sound source. Now let’s talk about proximity effect; this is a huge problem. As most of you know, the proximity effect comes from microphones being placed too close to a sound source, resulting in an undesirable low-end boom in your tracks. Sometimes this can be filtered out without much of a problem, but why do that when you can do things correctly from the get-go?! So let’s start a good 10-12 inches away from our sound source (our acoustic guitar or mandolin or whatever it may be). One microphone aimed at the bridge of the instrument, and the other aimed at the neck. Try swapping the mics to see which is yielding a better capture for each side of the instrument.
Using these two signals in the mixing stage is where the fun comes in! Make note of which mic you placed on the neck and which one is on the bridge. Pan them in any way you see fit for you mix. Enjoy!
-Josh Franklin, MediaTech Institute Alumni