A DIY Acoustic Guitar Recording Primer (Part I)

For Part II of this article, please click here.

Cliff Goldmacher is a songwriter, producer, engineer and the owner of recording studios in both Nashville and New York City.  Cliff is also a regular contributor to EQ Magazine and Pro Sound News.  He can be reached at cliff@cliffgoldmacher.com.

Let’s assume that along with releasing your music online, you’re also a budding recording engineer and would like to record your music with you as the acoustic guitarist.  Here are a few tips that I’ve gathered in my years of doing exactly that.  Like a lot of musicians, I tend to wear several hats in the recording studio.  Along with engineering and production, I do a lot of my own acoustic guitar work.  The issue here is that in order to effectively engineer and play acoustic guitar at the same time, I’m forced to record in the control room so that I can run my Pro Tools rig.  Over time I’ve cobbled together an approach to help me get a clean, full and detailed acoustic guitar sound without using an isolation booth or bringing in another engineer. 

As there are a lot of details to cover, I think it might be best to split this article up into two parts with the more technical information coming in part two.

To Plug In or Not to Plug In?

While it may seem like the obvious way to go, I’m not a fan of using on-board pickups in acoustic guitars when I record.  While it’s true that plugging in a 1/4” cable to your guitar and plugging the other end straight into your DAW will effectively remove all room noise from the recording, the sacrifice you make in tone is too great to justify.  There are quite a few great-sounding piezo electric pickups on the market these days and when run through a live PA, they can sound full, clear and even woody.  However, a large part of the sonic beauty of the acoustic guitar lies in the way the instrument pushes air out of the sound hole.  A plugged-in guitar is only translating the vibration of the strings and loses the essential “acoustic” nature of the sound.  On top of that, because acoustic guitar pickups are often designed with stage performance in mind there’s the likelihood of a slight hum or buzz which while unnoticeable on stage in a live venue can be extremely distracting when scrutinized in a studio recording.  All this to say, unless you’re consciously going for the particular sound that a plugged-in acoustic guitar gives, avoid the easy way out and try a few of the tips I’m suggesting below.

The Room

Let’s face it; there is no trick or secret that can take the place of a quiet room for recording. So let’s start with the obvious.  Do everything within your power to control the environment in the control room before you even get started.  You might want to put up some sound absorbing panels on the walls nearest your set up.  You can even go as far as to put sound diffuser panels on the ceiling above you.  Essentially, you’re trying to deaden the environment closest to you so you won’t be recording a lot of room sound with your acoustic.  While it’s fairly easy to add reverb to simulate different spaces once the guitar is recorded, it’s practically impossible to remove the sound of the room you’ve recorded in if it’s too present in the recorded sound.  The one place I like a hard surface is the floor.  There’s something bright and clear about the tone of the acoustic when the mic is picking up some of the reflections of the sound coming up off of the floor.   Also, distance yourself as much as possible from your computer to minimize the volume of the fan noise.  Of course, since you’ll be recording yourself, you’ll need to keep your computer within reach but you can always improve the odds by facing the microphone towards your acoustic and away from the computer.  And speaking of microphones…

Mic Choice/Placement

There are many, many microphone choices you can make when recording an acoustic guitar and each has its own merits.  For my ear, a large diaphragm condenser mic set in a cardioid pattern and pointed at an angle where the guitar neck meets the body at a distance of about six inches works best.  There are several reasons for this.  First of all, I like the broader spectrum of tone I get when I use a large diaphragm mic as opposed to a pencil mic. Secondly, the cardioid pattern focuses the recording field which helps remove the questionable environment of the control room. Finally, by not pointing the mic directly at the guitar’s sound hole, you get the fullness of the tone without all the low mid “woof.”  The proximity of the mic to the guitar also enables you to get a much higher direct sound to reflected sound ratio. As I mentioned above, make sure to angle the mic so that its back is toward your computer in order to minimize what is probably the loudest piece of gear in your control room.  If you’ve got a bit more budget than most when you put together your studio, you can also consider some sort of isolation cabinet for your computer but it’s not essential.

Check back for part II next week!

Comments

[Robby M]

Hey guys, we tried recording an acoustic track in an isolated room mic'd up (because there were problems with the ac-guitar pickup) and there are far too many picking sounds that have come onto the track. Otherwise the track sounds great. Any suggestions?!

[Billy Zenn]

I often lay a basic DI acoustic guitar track while playing in an open room with a drummer, along with a reference vocal. Later, I double track the original part by putting two mics on the acoustic and sending them to two seperate tracks. As I play pretty consistently, this approach allows me to hard pan the new tracks right and left and keep the original DI track in the center for a large, beautiful acoustic sound. Thanks for a very informative article.

[George Piazza]

One trick to try if you are recording acoustic guitar and vocals at the same time, and have a large diapragm mic with a figure 8 pattern is to place that mic where the neck meets the body, facing sideways (and possibly horizontal to the guitar - the top of the mic is aimed at the guitar); this way it picks up both the neck area and the body, and the figure 8 provides off-axis rejection from the vocals, since the side of a figure 8 pattern is the least sensitive spot on the mic. This also might be good for reducing room noise.
I also agree that recording the d.i. at the same time is well worth it if you have enough tracks; this provides more mixing choices and serves as a backup in case something happens with the mic recording (the player bumped into it at one point, or the vocals are too loud at some spots); the only caveat is to check the mic and d.i. signal for time offset and phase coherence. Time offset can be corrected by moving the offending track to sync up with the other (or a 'sound delay' plugin) - just zoom in on a good attack point in your wave view, and align the rise and fall pattern as closely as possible. It is amazing how effective this can be for a fuller sound.
Phase is trickier: if 180% out of phase, the signal will sound hollow and lacking in low frequencies. To solve this, flip the phase (polarity) button of one of the guitar tracks (incidentally, this is another way to reduce guitar/vocal bleed - by inverting their relative polarities so that the vocals are somewhat cancelled out in the guitar mic, or visa-versa); if the phase is offset somewhere other than 180%, there are several great plugins on the market that can fix this problem, including the PHA linear phase rotation plugin by Voxengo and the phase plugin for the UAD cards (I forget its name). In fact, these phase plugins can be a lifesaver for any multi mic recordings, especially drums.

[Susan]

I enjoyed hearing the Dutch music--my Dad always said we are largely Dutch so I wish I wish I understood the language. I appreciate all these great comments on recording acoustic guitar and have also found it possible to record while playing the instrument as well as the engineer role. My G5 doesn't seem to crank out as much fan noise as some,(another producer noticed it) but I'll try throwing something like a blanket over it.We have a project called ALABASTER ROAD on itunes and others...Have any of you tried using two microphones? I notice if I use my Gibson as opposed to my Norman, I'm going to have to adjust EQ...and whether you play with fingertips, fingernails, or a pick makes a huge difference. A little TruVerb 'New York plate' is always nice. As someone said before me, if it sounds great, it is a good technique even if others don't subscribe to it! Keep the ideas coming!

[Calgar C]

heres a micing trick i use on my dorm room. i use a headphone amp and a 20ft xlr cable to extend the reach of my mic. this way i can record in my bathroom. i also use some pillow covers to cover my computer and other parts of my room. the only downside is i have to keep going back and fourth from room to room when recording. i also use a larg diaphram condenser. also when working with electric guitars i plug directly into my firepod and use vst's to control the sound, not as nice as an amp but still good.

[Dennis White]

or try this link for more examples...

[Dennis White]

or....

[Dennis White]

...I've heard of using a pencil to eliminate the plosives, but one of the reasons to use a screen is to keep moisture out of your expensive condenser mic... but I guess we're off topic at this point... I use a stereo mic on my acoustic guitar - at about the 12th fret, as usual, with nice results. I hugely prefer micing vs running direct - I've done both, but have come to love the presence of the sound when just mic-ed - and, yes, we use an isolation booth.

[Ben]

On the last album I produced and recorded Ac Guitar for we used a direct plugged in sound and also mic'd it up. We then panned these hard left and right for the mix and the result was great! In the process of doing the next album now, and will be experimenting using a really nice Martin Guitar, with a Neumann U87 through a focusrite ISA 220 Pre, and will also record the direct sound. It has pickups and a builtin Mic as well.

[Michael]

Silly not to plug in AND use mics. It's all about the blend..

[BlueRick]

I like to record acoustic guitar using a combination of microphones and recording direct using the installed acoustic/electric pickup I have in my guitar. Then I mix them during playback to taste.

[Ron Baak]

This is very interesting, I have recorded as a hobby. I have noticed that my acoustic sounds hollow with out the sustain that I place in on purpos, I use the same method as cliff does when placing the Microphone 6 inches from the center of the guitar. Then I regain my sustain when I edit the sound track. I am using a Digital Mic by MXD USB.006 I have a sock to cover it, I am starting to think that my sound proof room isn't so sound proof.

[Greg Alton]

In my first recording session, I plugged in my acoustic and sang, expecting isolation. I also liked the effect the pickup provided. It seemed easier to play the songs as I normally would, rather than trying to keep track of where I was without the vocals. Later, I was surprised to hear the vocals bleeding through my acoustic pickup!

[Buck]

Good point; using a microphone as opposed to being lazy and plugging in. An acoustic electric will never sound as good recorded plugged in as if captured using a microphone (in most instances, especially in lower price point models). What was neglected though, is the ability to do both, if you're recording system is capable of capturing two or more channels simultaneously. Using a microphone as well as using the direct line out at the same time has benefits when it comes time to mix.

Not so good point; If recording in a less than stellar acoustic environment, a small diaphragm condenser microphone is more ideally suited, as they are more accurate in rejecting and capturing off-axis sound and or reflections. The large diaphragm microphone may give you a better sound (oh so slightly) when it comes to capturing the acoustic guitar, but it will also capture more of the sound you don't want, which is what you're trying to avoid. As far as "spectrum" is concerned, similar quality microphones, whether small or large diaphragm, will have the same frequency response, which is usually 20hz-20,000hz. And what wasn't mentioned, and in my opinion is the easiest fix of all, is by using a reflection filter. SE Electronics makes a "Reflexion Filter" for $300, but a creative, and budget-minded engineer can make such a toll by using a cardboard box and acoustic foam, blankets, and some duct tape...not pretty, but functional for sure...and you can get the same type of results as when recording in a booth. Similar to using a wire coat hanger and one of your wife's or mom's old pair of nylon' to create a pop-filter.

The only other point is to say experiment with microphone placement. Each player strokes their guitar differently, and should use their own microphone technique as well. Six inches distance from the fret number twelve has been a staple technique, rotating the face of the diaphragm toward or away from the sound hole for more or less bass respectively. In some cases it's also appropriate to aim your microphone at the bridge of the guitar...but the most important thing to remember is that there are no rules when recording...period...the sound you may prefer might be plugging into an amp in a closet full of clothes and then mic'ing the amp...for an example...but do whatever you want...if it sounds good. And as the engineer, you dictate what you want it to sound like and are the judge when it comes to your recordings...if you like the way it sounds, to hell with other peoples opinions.

[jay.soul]

some useful tips