Recording Acoustic Guitar: Part I, Stereo or Mono

Last week, we focused on tips and techniques regarding recording the electric bass – specifically dealing with that low end frequency. We found out that there are certain inherent problems when dealing with such low bass frequencies and certain techniques to best negate them. When dealing with mixing the bass on a complete track for example, we found out that certain monitors won’t be able to properly reproduce all of the low end frequencies that are present in the mix and although a bass track might sound properly balanced at home, playing it on a different system that can handle a deep bass might play it back completely different. Plenty of other tips and tricks too so check it out in case you missed it. This week, we will be delving in just as deep with another common instrument that any good producer should know how to handle.

Although this might not be the case for some of the more exotic players out there but for the most part, all of my rock songwriting buddies, along with myself, tend to mold and craft an original song by simply using an acoustic guitar to sing along with. Sometimes, we record ourselves and our guitar in order to make a rough sketch of our tune but also, we might use the acoustic guitar track as the backbone of an entire mix with other instruments added later. Regardless of the reason, I’m fairly certain that everyone out there recording acoustic guitar for their project would want to create the best possible track possible, and although it might seem fairly straight forward, there are a few things that every home studio producer should know. What kind of mic should you use? What about EQ? Maybe some compression? All questions you should ask, but here's one you should start with: should I use one microphone, or two?


 Stereo or Mono Recording for Acoustic Guitar

Alright, before we get into some of the more complex matters in dealing with the acoustic guitar in studio recording we must decide how exactly we want to go about recording and believe me, it certainly does matter how. Unless you have an acoustic electric guitar and plan to record using DI along with all of its pros and cons (clean unadulterated signal but can sound lifeless and flat), you will be recording using a microphone, but now the question is, do you do a mono recording or a stereo recording, that is to say, will you be using one mic or two? The choice is really up to you but there are a few things you should keep in mind that will probably work better depending on your situation.


Stereo Might the Better Choice

For the most part, most musicians like to record their acoustic guitar using only one mic precisely placed pointing at the 12th fret, but using two mics for stereo recording does have its advantages. First of all, you are able to record the entire instrument instead of just a small portion of the guitar. Different parts of the guitar have different tonal characteristics and the more of these that you capture in the recording, the truer to the instrument it will sound. If you were to record your acoustic guitar using a mic pointed more towards the neck of the instrument, you will get a lot of high end while recording closer to the bridge will give you a lot of that low end. Simply put, if you want to record the best possible range of high and low frequencies for your acoustic track, using stereo recording is your best bet, otherwise you will end up with a fraction of the frequencies that are not nearly as wide in range.

A common problem with recording and mixing acoustic guitar track along with a mono vocal track is that although the entire mix might sound pretty solid, it can be a bit lifeless, that is to say, narrow and flat. Some people negate this by adding a plug in or two while mixing, such as reverb in order to thicken up the sound but the problem with this route is that it rarely sounds natural. That same fuller feel can be created by the sound separation created in stereo recording. Think of it kind of like adding simple surround sound to your mix. Basically, when using two mics, they will pick up sound from the same source at different times. Although this difference in time in very small and almost indistinguishable, our brains can pick it up and what is essentially two mono tracks can become combined to sound like one, full track with plenty a lot more depth than a normal mono recording. If you have ever tried to make a basket having only one eye open you can clearly understand how having two eyes giving you two images mixed together as one becomes undeniably important in creating depth perception and the same holds true with using two mics instead of one.

And finally, using stereo recording allows you to be able to record with the mics much closer to the guitar than if you were using only one mic (since the two have to pick up less in order to sound just as loud as one). The reason having your mics closer is a benefit is because the closer you are to your instrument, the less noise you will pick up – plain and simple. Unlike electrified instruments can adjust their volume through an amplifier, acoustic instruments use natural acoustics for their output level which is nowhere near as loud. Certain noise that we don’t even think about when recording off of a loud amp – such as AC in the background, kids playing outside, cars honking in the distance – cant simply be drowned out when working with a much quieter instrument like the acoustic guitar, and while having a sound proof work area is by far the best way to cancel out all noise, having the ability to record placing your mics a bit closer to the instrument can help when outside noise is out of your control. It might still pick some up, but not nearly at the same level as if you were using a single mic.


On Second Thought,  Mono Might Be Better

Alright, so now that we have laid out some of the benefits of stereo recording, is there ever a situation where mono recording would be a better bet? Yes actually, a few in fact. Taking a look back at the first reason why you would want to record using stereo recording, that is getting a truer recording sample of the instrument, that might not be such a good idea if your acoustic doesn’t sound particularly good. Stereo recording may be a great way to bring out the entire sound of your instrument, but if your guitar’s tone isn’t ready for primetime, having that entire sound won’t really do you any good.

Another reason why you might want to avoid using stereo recording is because you don’t want to deal with phasing issues. As mentioned above, mics recording sound from the same source might record them slightly off from each other, and while this does a lot to create a fuller sounding track (before stereo records were the norm producers would have two mono tracks slightly out of phase with each other to create a similar fuller effect), you may find yourself dealing with a comb filter effect. It pretty much sounds kind of like using a flange or a phase effect and although it probably sounds nice with an electric guitar, it might not be what you were looking for in your acoustic track. You can fix this issue by making sure the two mics are exactly the same distance from the sound source or fix it in the mixing stage using common phase fixing techniques (like the ones stated in our bass recording article) but that is much easier said than done. Or you can simply record using a single mic.

And finally, if the acoustic guitar you’re recording isn’t going to be the prominent instrument in your mix, there is really no point in recording using the stereo technique since much of the benefits added – along with all of the extra time it will take to make use of those benefits – will all be a waste since the other instruments will assuredly drown them out. Just like deciding between DI or mic to amp with bass recording or deciding what effects to use, your choices should reflect what works best for the entire song.  



Tomorrow We Tackle EQ

Alright, now that we know about the pros and cons of stereo and mono recording on an acoustic guitar, we can move on to a few tips and tricks to use once you have that track down, but it will have to wait for tomorrow when we will be taking a look at how to EQ an acoustic guitar along with common problems and their solutions.

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