# Know Lots About Miking Acoustics:



## Chris

*Three stereo miking secrets guaranteed to make your acoustic guitar tracks shine.*

Ask five engineers how they approach recording acoustic guitar, and you may very well get five different answers, if you get any at all, that is. While many factors influence an engineer's choice of recording techniques -- the character of the instrument, the style of music, the player's personal tonal and dynamic signature, and the recording environment -- some engineers prefer to keep their approaches a trade secret. But despite all the possible permutations of instrument, style, player, room, and ego, for most seasoned engineers the real secret to recording an acoustic guitar is stereo miking -- plain and simple.

Sure, if it's just "spaciousness" you're after, you could record an acoustic guitar in mono and fold in some enthusiastic stereo processing. Or if you're hankering for a dramatically textured sound, you could try combining a microphone with an acoustic guitar pickup. If depth and accuracy are what matter most, however, you'll find that stereo recording with two microphones is an exceptionally reliable way to record full-bodied, realistic-sounding acoustic guitar tracks. 

Let's take a look at three of the most popular techniques, and also examine the questions of microphone choice and mono-compatibility. As you'll find, stereo recording can be a complex art, since the interaction between the two mics will determine many aspects of the sound -- including tone, image, and mono-compatibility. But like any art, you'll also find that practice makes perfect. So whip out those mics, pull out that guitar, and give these tips a try: You'll hear the difference.

Three Surefire Techniques 

In most cases, you'll want to use a pair of cardioid (unidirectional) mics placed close to the instrument. Close-miking -- approximately six to 12 inches from the guitar -- is used in most pop and other contemporary recordings that feature acoustic guitar.

Cardioid mics are generally best used for close-miking guitar because they exhibit less bass proximity effect (or bass boost) than other directional types when placed close to the sound source. And we all know that acoustic guitars can sound boomy if miked incorrectly.

Let's explore three common approaches to stereo miking and acoustic guitar. Each of these techniques has been used on countless hit records. Be sure to check out the corresponding audio links, and of course, consider these as starting points for your own creativity. After you've mastered each one, feel free to experiment with your own variations on each method.

Spaced Pair, Version A

Two mics are placed apart from each other at the same approximate height, one pointing at the 12th fret of the guitar and the other at the bridge.







With this approach -- as with any miking technique that uses two or more mics that are spaced apart from one another -- always be sure to follow the "3-to-1 rule." According to this rule, the distance between two mics should be at least three times the distance between each mic and the sound source. This keeps phase cancellations to a minimum, resulting in a smoother sound that also translates well to mono. So, for instance, if you've got each mic seven inches from the guitar, the 3-to-1 rule mandates that you spread the two mics at least 21 inches apart from each other. (One of a few exceptions to the 3-to-1 rule is with the X-Y technique, as described below


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## Chris

Spaced Pair, Version B

Our second technique is a variation on the spaced pair. As in the setup above, one mic points to the 12th fret. The second mic, however, is hung from a mic stand at the performer's ear level, pointing down at either the bridge or at the strings just behind the soundhole. For example, if the performer is right-handed, this second mic would be placed over her right shoulder. (Once again, be sure to follow the 3-to-1 rule.)







You can also move this ear-level mic slightly out in front of the performer and angle it back towards the guitar (versus pointing straight down at the floor), for a brighter sound. This technique usually yields a more open -- but thinner -- sound than the simple spaced pair on a horizontal plane. Check out the links to hear the difference.

If you're not getting the sound you want with a spaced pair placement, try moving one or both microphones slightly to improve the timbre. Because spaced pair placement is subject to phase interference, moving one mic only an inch or two can dramatically change the sound. To learn more about how phase affects the timbre of stereo guitar tracks, go to the mono-compatibility link below.

The X-Y Technique

X-Y, or coincident-pair, is the no-brainer approach to stereo miking. If you follow these steps precisely, and are willing to move the mics around a bit to find the sweet spot, you'll find it's hard to make a bad recording. (That's assuming, of course, that your room, your mics, and the instrument -- and, while we're making a checklist, the guitarist -- are half-way decent.)

Place the two mics close together so that their capsules are almost touching. The rear ends of each mic are spread apart at an angle of a roughly 90 to 120 degrees. The result looks like a wide V shape, with one mic's capsule positioned directly above the other.






(The 3-to-1 rule doesn't apply to the X-Y technique because the two capsules are so close that sound waves arrive at both at essentially the same time, minimizing objectionable phase cancellations.)

To start, try placing the two mics opposite the 12th fret of the guitar. If you have a really nice sounding room to record in, try backing the mics up to a distance of one to two feet from the guitar. This will capture more room tone and yield a more natural sound. While the best-sounding position can depend upon the guitar, the room, or the mics, typically, placing the mics around seven inches in front of the guitar's 12th fret will tend to de-emphasize midrange frequencies. That's because one mic will be pointing in the direction of the bassy soundhole, and the other towards the top of the neck, an area rich in high frequencies.

As you experiment, you'll find that the X-Y miking produces a much narrower stereo image than the spaced-pair techniques. But you'll also hear how X-Y lends a smoother, warmer, and more natural sound to acoustic guitar.


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## Chris

Choosing the Right Mics 

By definition, stereo miking requires a pair of microphones. Certain types of recording situations -- such as chamber orchestra, or an acoustic jazz trio -- demand extreme accuracy, and in these cases, it's highly desirable to have a matched pair of microphones. This means more than just two of the same model; it also calls for two mics that have been factory-certified to produce virtually identical frequency response. (Some, though not all, manufacturers sell matched-pair mics.)

Fortunately -- unless you're, say, capturing an audiophile-quality classical guitar recording -- you won't need a matched pair to record acoustic guitar tracks. In fact, you might not even need to use two of the same model of microphone (though if you do you'll get a more consistent timbre in each channel than if you had used two totally different mics). That said, rules are meant to be broken, so feel free to experiment by mixing and matching mic models. And like any musical instrument, every mic has its own sonic character, so try to get your hands on as many different models as possible and experiment.

Generally speaking, condenser mics are the right choice for acoustic guitar. As a group, they offer a far more detailed and realistic sound than dynamic mics. But before you choose a specific condenser, first decide what kind of sound you want. Small-diaphragm condensers (those with a diaphragm smaller than one-inch in diameter) generally offer a better transient response than their large-diaphragm cousins, producing a less colored, more detailed sound. For pop and country productions where guitar tracks will be tucked into dense arrangements with drums and bass guitar, small-diaphragm mics are often the best choice.

Many engineers consider the AKG C480B ($987 with the CK61-ULS capsule), Neumann KM184 ($729) and DPA 4011 ($2,190) to be among the best small-diaphragm condensers on the planet. (All list prices are in US$.) All three sport cardioid (unidirectional) patterns -- meaning they tend to reject any sound that isn't directly in front of them -- and sound awesome on acoustic guitar. (Cardioid response is also required for most stereo miking techniques, in order for the resulting recording to have a "left-to-right" soundstage.) AKG's C480B is a modular mic, meaning that you can interchange various capsules -- each offering a different polar pattern -- with the mic body that holds the internal preamp. This mic features a 70Hz high-pass (low-cut) filter, useful for rolling off unneeded low frequencies when recording acoustic guitar. 

The Neumann KM184 exhibits an inherent low frequency roll-off at 200Hz, delivering guitar sounds free of low-end "boominess." DPA's 4011 mic -- known prior to 1998 as the Brüel & Kjær (B&K) 4011 mic -- features a 1dB roll-off in the midrange frequencies along with a 1dB rise between 10 and 15kHz. The result is a crisp, though not overly bright sound. This 4011 has treasured place in many mic lockers (including my own). Check out these links to hear the DPA 4011 on a Guild M20 acoustic guitar, with various mic placements. 

There are plenty of other small-diaphragm, cardioid condensers on the market, many of which offer decent performance for a lot less scratch. Some better-known alternatives that other enginneers report good results with include Shure's SM81 ($530), AKG's C1000S ($297), and Audio-Technica's AT3528 ($259). 

Large-diaphragm mics -- those featuring diaphragms at least one inch in diameter -- can also provide outstanding results when recording acoustic guitar. All other things being equal, these mics tend to offer a slower transient response than their small-diaphragm counterparts. This causes a slight de-emphasis in high-frequency detail and tends to give them a rounder, warmer sound -- just the ticket for traditional jazz recordings and lean guitar/vocal arrangements. (It's this warmth that makes large-diaphragm mics so popular with vocals.) The Lawson L47MP Tube Condenser ($1,995) sounds great on acoustic guitar for these applications. I've also used the Manley Reference Gold Tube Condenser ($5,500) with excellent results. On a budget but craving that large-diaphragm condenser sound? Some candidates that I didn't have the chance to work with would include AKG's C414B/ULS ($1048), Neumann's TLM103 ($995), the Alesis AM51 ($549), and the AKG C3000B ($478).

And what about a dedicated stereo microphone? These mics -- such as Shure's VP88 ($1194) and Audio-Technica's AT825 ($525) -- typically have a pair of cardioid capsules mounted in one housing. While they may be useful in certain applications, they're actually less flexible than a pair of independent mics -- since their diaphragms are physically fixed relative to one another. In other words, if you want to try some of that mic-above-the-bridge, mic-above-the-fingerboard stuff, or any other interesting variations, you'll want a pair of mono mics.


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## Chris

Mono-Compatibility, EQ & Compression 

Stereo-Miked Acoustic Guitar Tracks and Mono-Compatibility

When stereo tracks are collapsed to mono, the result can sound dramatically different from the original tracks. This is not only true of the listener's perception of the width of the stereo image and the discrete placement of different elements in a mix: Conversion to mono can also significantly change the timbre of individual instruments, especially if certain stereo miking techniques were used to record the original. (In rare cases, the instrument could even disappear from a mix, should the left and right signals be far enough out-of-phase to cancel each other out when combined to mono.)

True, in the last couple of decades -- with AM radio's diminishing role as a music medium -- mono-compatibility has become less of an issue. And in fact, some engineers prefer not to compromise their stereo tracks or limit their recording techniques to cater to the lowest common denominator. Still, many engineers choose to play it safe -- ensuring that their miking (or other processing) techniques won't sound terrible if played back in mono. However you feel about this issue, you'll be able to make more informed choices on how to record if you know what the sonic repercussions will be for mono playback. So what exactly happens to stereo acoustic guitar tracks when they are collapsed to mono? The answer depends on what miking technique you use to record.

Spaced pair techniques generally pick up a high degree of uncorrelated signal for each track. That is, many frequency components on the left-panned track are more or less out-of-phase with corresponding frequencies on the right-panned track. (This still applies even if you use the 3-to-1 rule for mic placement.) 

This is because each of the sound waves emanating from the guitar will arrive at each mic at a different time. Due to that time difference the mic will pick up the wave at a different phase of its cycle. When the stereo signal is collapsed to mono, the constructive and destructive interference of these out-of-phase components combine to emphasize and de-emphasize their corresponding frequencies. The resulting timbre can be markedly different from your carefully crafted stereo tracks and can play havoc with your mix. You might be able to compensate with EQ, but this might exacerbate the problem. 

Tracks recorded with an X-Y technique are far less prone to phase problems. Since the capsules are placed so close together, the sound reaches both mics at roughly the same time. As a result, tracks recorded in X-Y stereo are much more mono-compatible than those recorded with a spaced pair.

You can hear these sorts of phase relationships by listening to the audio samples linked below. The samples are grouped in pairs playing the same track recorded in stereo and then collapsed to mono. The first examples ("Spaced Pair" and "12th Fret + Right Ear") were produced using spaced pair techniques. You'll notice that the spectral balance -- or timbre -- of these stereo tracks does not survive the conversion to mono very well. The mono versions have exaggerated peaks and dips in the frequency response. Compare this with the X-Y examples: Note how much more consistent the timbre is between the stereo and mono versions. Unlike the spaced pair recordings, the mono and stereo X-Y samples sound quite similar.


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## Chris

*A Word on EQ and Compression*

Aside from the occasional use of a microphone's passive high-pass (bass roll-off) filter, I prefer not to add equalization to the signal I'm recording. You can never tell in advance exactly how yet-to-be-recorded tracks will interact with the guitar you're recording, so any processing you add during recording is just a guessing game. Since you'll probably need to make subsequent adjustments in timbre (and possibly dynamics) at mixdown, you should avoid processing the signal twice. Your tracks will sound more pristine if you hold off adding processing until you have a complete picture of how the tracks will fit together. Instead, if you're not getting the sound you want during soundcheck, move the mics around until the timbre sounds right.

If you want to experiment with EQ as you're tracking, you can record the music dry and add EQ on the monitor returns. This way, you can hear the results of the EQ without committing to it.

Though many engineers will compress an acoustic guitar during tracking, I usually don't like to do so. As with other broadband, percussive instruments, guitar can easily cause a compressor to pump (cause audible changes in level) if it's not set up exactly right. Once these amplitude modulation artifacts are on tape, they are all but impossible to remove. For this reason, I compress acoustic guitar tracks at mixdown -- when I have multiple opportunities to get it right.


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## Drew

You know, this thread hasn't been touched in more than a year, but that's a GREAT read. 

It also makes me wish I had about $5k to drop on good condensors, lol. Does anyone have any experience with affordable condensor mics? I was thinking of grabbing a set of these largely for the price ($130) http://www.musiciansfriend.com/srs7/g=live/search/detail/base_pid/273168/ but a lot of the reviewers have found the MXL993 a little bright for acoustics, and there are apparently some durability concerns with the 990... They also offer a set of 993's in a case for $199, which would probably be better as a set for acosutic stereo micing, but less so as a set of general-purpose guitar mics, as they're probably be pretty bright for amp micing...

-D


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## Drew

http://www.soundonsound.com/sos/aug01/articles/recacgtr0801.asp

Another great article I'm miday through, maybe later on I'll rip it into the forum in case the server goes down.


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## TonyFlyingSquirrel

TO ADD TO THAT, TRY RECORDING ONE TAKE WITH YOUR STANDARD PICK, THEN TRACK IT AGAIN USING A JELLIFISH. (JELLIFISH.COM)

IT'S BECOME ONE OF MY MOST VALUED TOOLS FOR RECORDING/PLAYING ACOUSTIC.


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## Drew

Dude, your caps lock is broken. 

As an update, I've found a set of AKG C1000s's in an X-Y array pointed about an inch over the 15th fret, bass side, sound absolutely phenominal. This is, until I find something I like more, my go-to acoustic micing strategy. 

Any of you guys have a lot of experience EQ'ing acosutics in a mix? For now I've been feeding both tracks into the same bus and then applying a master EQ there, but I'm open to other suggestions.


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## TonyFlyingSquirrel

WHEN JUST USING A SINGLE CONDENSER MIC, I PLACE THE MIC ABOUT 18 TO 24 INCHES AWAY, DIRECTED AT THE 12TH-15TH FRET.

I START WITH THE EQ SET DEAD FLAT, & ADDRESS ANY TRANSIENTS OR STANDING WAVES ACCORDINGLY. MY PREFERENCE IS TO ROLL OFF ANY OFFENDING FREQUENCIES BEFORE INCREASING THE AMPLITUDE OF ANY DESIRED ONES, THIS KEEPS THE GAIN STRUCTURE FROM CONTINUING TO CLIMB.


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## Drew

Ignoring the Wall 'O Capitalization, that's good advice for any instrument - cut, not boost. It apparently adds less distortion to the signal, but additionally it's easier to create a better overall mix when you're not making different parts louder to make them jump out, but rather removing frequencies you don't need to emphasize the ones you do. 

I almost never boost EQ.


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## Vince

Drew said:


> Dude, your caps lock is broken.
> 
> As an update, I've found a set of AKG C1000s's in an X-Y array pointed about an inch over the 15th fret, bass side, sound absolutely phenominal. This is, until I find something I like more, my go-to acoustic micing strategy.
> 
> Any of you guys have a lot of experience EQ'ing acosutics in a mix? For now I've been feeding both tracks into the same bus and then applying a master EQ there, but I'm open to other suggestions.



I agree with you, Drew, the 12th-15th fret XY is the best IMO.

I've recorded acoustics on 5 songs on our current project, and the best sound came from using that technique.

I also used another technique that gave a different, darker sound. Instead of recording stereo tracks with two mics, I recorded two mono tracks (separate takes) with 1 mic placed at the 12th fret. Then I recorded two takes with the mic up in the air about 2 feet above the guitar neck, pointing down onto the guitar, aimed at about the 12th fret. When I grouped these 4 takes together, it gave me a really nice saturated acoustic sound that was a little darker than the XY technique.

So I'm using both for differences in texture, but for the future, if I had to choose one technique, it'd be the XY.


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## Vince

Here's a couple examples. This is my kind of acoustic guitar sound. I'm not sure if I've posted these clips before on here anywhere, but these are IMO good examples of what we're talking about.

The first clip is using the XY technique. You're hearing a rhythm acoustic guitar and a lead acoustic guitar, both miked in stereo XY at the 12th fret. This is a short clip from the song "Boundaries" off my next disc:

[MEDIA]http://www.vincelupone.com/mp3/VINCEboundacous1.mp3[/MEDIA] 

The second clip is using the other technique I mentioned in my last post, where we're using mono tracks, more takes w/ different mic positions, and layering the takes. Also of note on this clip, I purposely have the guitar set up with bright fresh strings for the highest three, and darker duller 'played' strings for the lower three. I wanted a dark bottom end with a sparkling high for this part. This is a clip from the intro to "Dorian Gray":

[MEDIA]http://www.vincelupone.com/mp3/VINCEdorianacous1.mp3[/MEDIA] 


Enjoy


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## Chris

Those sound great man. Both a little too bright for my ear, and the bottom end is a lot tighter on the second one than the first, but all in all a good start. The first sounds great on the high end, but there's just not enough low end for my tastes.


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## Drew

[MEDIA]http://www.drewpeterson.org/recording/acoustics_solod.mp3[/MEDIA]

Here's a clip of my acosutic tone, first with one mic solo'd, then the other, then both together. It's not perfect, this was done quickly, but you can hear the contrast between the two, and how together it gives you a bit more space. I go for a slightly bluesier acoustic tone than Vince.. His is very clear and "classical," somehow, whereas mine's a lot darker and bluesier. 

As always, Vince, those clips kick ass.


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## Jongpil Yun

TonyFlyingSquirrel said:


> TO ADD TO THAT, TRY RECORDING ONE TAKE WITH YOUR STANDARD PICK, THEN TRACK IT AGAIN USING A JELLIFISH. (JELLIFISH.COM)
> 
> IT'S BECOME ONE OF MY MOST VALUED TOOLS FOR RECORDING/PLAYING ACOUSTIC.



Jellifishes give terrible screeching sound on steel strings though. Even though I can't finger pick worth shit, I think the sound of your nails is the best.


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## bulletbass man

If price is an issue you can't go wrong with Rode. With the exception of a poorly designed shockmount (they drilled the hole too far in so It can't get full rotation) I love mine.

Large Condensor Microphone- Rode Nt1. Roughly $250
Stereo pair condensors Rode NT4s Roughly 430 matched pair.
single XY condensor mic Rode NT5- 400 if i remember correctly.

Great quality of sound for a very cheap price. Not quite the dynamics of a high end Neumann but for the price they cannot be beat in my honest opinion.

Personally I use a micing similar to figure one. But also use a large condensor mic in front of the soundhole. With proper mixing and eqing it gives a very precise sound. And is especially nice with nylon work. For steel string I usually just use a stereo pair.


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## OwainXerath

Fuck Rules! Get a decent pair of headphones, get the artist to play and move the mic 'round whilst listening. My "latest" best sound was 1 DI track and an AKG3000c pointing at the neck/body join (if not slightly pointing towards the body). My previous best was 3 Rode NT2's and an NT3 pointing wherever. It depends on the room.


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## Seven Samurai

Check out the tone they captured on my acoustic. The song I played on HAVE YOURSELF A MERRY LITTLE CHRISTMAS. You can hear it here...

Have Yourself A Merry Little Christmas

I did three sessions in the last week at a high studio in Nashville - I'd guess there was a million dollars of gear in there at the minimum. There were two engineers setting up the guitar sound. The songs were just a female vocalist and acoustic guitar. I was very happy with the guitar tone on the recording - the best I've experienced yet.

They used two Shure KSM32 mics placed like this....

One mic was placed parallel to the neck of the guitar, with the grill end of the mic pointing toward the bridge and the bottom of the mic (where the cable connects) pointing towards the headstock. It was placed about 8" directly in front of the sound hole with the diaphragm POINTING STRAIGHT DOWN TO THE HARDWOOD FLOOR.

The second mic was place with the grill end of the mic pointing straight at the sound hole with the cable end of the mic pointing away from the guitar at 90 degrees with the diaphragm POINTING STRAIGHT UP TO THE CEILING. The top/grill of the mic was about 8" directly in front of the sound hole.

The two mics were almost touching - maybe 1/8 of an inch apart at the grill end and at 90 degrees to one another - in an "L" shape.

Before placing the mics, one engineer had me play while he had his ear right down in front of my guitar. He moved his head around listening until he found the sweet spot. Thats where the two mics were placed. Unless you are a circus contortionist this may be difficult to do when recording at home by yourself. What I plan to do is put on the headphones and have one of my kids hold the two mics at the 90 degree position and move them around in front of the sound hole until we find the right sound. Another way to find this spot is to strum a chord, and while its still ringing pick up your guitar and hold it so that the face of the guitar is right in front of you (a few inches from your head), turn your head to the side so your ear is facing forward, close your eyes and move the guitar around so that your ear getting to hear the sound coming from various points of the guitar face as you move the guitar around while the chord is ringing out. You will hear significant differences in tone as you move the guitar around.

They kept the EQ pretty flat but added a bit of high end EQ to add some sparkle, a bit of compression, and some really nice reverb. I was playing my Dell'Arte dreadnaught with Curt Mangan strings which is a pretty sweet combo.


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## Fragile Balance

Hey, saw this thread and thought I might offer some insight on what you can do with the SMALLEST recording budget. I just recorded and engineered an album for my acoustic band and our budget was very limited, but we found pretty good results with the AKG Perception 170. It's only 100$, and if you mix and master it well enough, you can get great sounds on a tiny budget. We always get compliments on our sound, and I would highly recommend it; for the price you can easy buy 2 or 3 to mic an acoustic sound with multiple points to record from.


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## FrankDeets

This is some great info thank you.


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## FrankDeets

I play upright bass and in jazz finding a good pic up can be difficult because I am often near the drummer and that can be picked up on the mic sometimes.


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