This is the last in my series on guitar tone that’s based around my book The Ultimate Guitar Tone Handbook (written with Rich Tozzoli).
Also available in this series:
- Getting The Ultimate Guitar Sound – Part 1
- Getting The Ultimate Guitar Sound – Part 2
- Getting The Ultimate Guitar Sound – Part 3
- Getting The Ultimate Guitar Sound – Part 4
- Getting The Ultimate Guitar Sound – Part 5
- Getting The Ultimate Guitar Sound – Part 6
- Getting The Ultimate Guitar Sound – Part 7
In the series I’ve discussed why acoustic and electric guitars, amplifiers, speaker cabinets and effects sound the way they do, and the best way to record and mix them after you’ve gotten the sound. In the last part of this series, we’ll look at the different ways to mic an acoustic guitar.
Like with the electric guitar, the acoustic has a number of miking possibilities and every engineer has their favorite. Here are a few of the more widely-used techniques as well as a few variations. One important thing to remember before you begin placing mics is that the sound does not come from the soundhole alone. Its tone is a combination of all the elements of the instrument – its body, neck, strings, and the integration of the overall design.
Using a single microphone is the easiest way to mike an acoustic guitar and usually provides a more than adequate result, but placement is the key to getting a sound that works in the track. Here are a few ways to get the most out of just that one microphone. Remember: the type or model of microphone isn’t nearly as important as the placement.
Single Mic Technique #1
Place the mic from 6 to 12 inches away from the point where the neck meets the soundhole (see Figure 1). This technique usually provides a good balance between the ambient sound and the highs and lows of the instrument, and is a starting point for many of the other techniques that follow.
To get a brighter sound, move the mic further up the neck, pointing slightly down towards the higher strings. For more bass response, move it down towards the soundhole, or point more at the bottom bass strings. Moving the mic closer to the guitar will also increase the bass response because of the proximity effect if you’re using a directional microphone. Moving the mic back will pick up more ambient room sound, and of course, moving it closer will capture more direct sound.
Single Mic Technique #2
Believe it or not, some engineers have gotten a great sound by placing a mic behind the players shoulder or head area, facing down onto the guitar (see Figure 2).
The two mic option adds a few alternatives in terms of positioning, since each mic can be placed on a different part of the guitar. Although the mics can be grouped onto just a single track, recording the mics on individual tracks provides more options during mixing.
Two Mic Technique #1 - Recording Different Parts of the Guitar
Many excellent recordings have been made by placing a single mic where the soundhole and neck meet, and another on the body (see Figure 3) for a bigger sound. When placing a mic on the body, it’s best to listen to the instrument first, as every guitar has it’s own unique projection. Once you’ve what you think is a sweet spot, place the body mic the same distance away from the instrument as the neck mic.
You can also experiment by moving the neck mic further up the neck to increase the brightness captured by that mic (see Figure 4), or further towards the bridge to darken the tone.
The reason you should try to place both mics at the same distance from the guitar is because any slight time delay between the mics, even if you don’t notice them during recording, can cause the mics to be slightly out-of-phase with each other. This means that certain frequencies can cancel out and make it sound hollow. An easy way to check the phase is to switch the phase or polarity parameter on one of the channels, either by applying a plug-in (make sure it has delay compensation) that has phase reversal or selecting it on your mixing console or microphone preamp. Choose the position that has the most low end.
This is one of the times in recording where it can be good idea to use two different types or models of mic, such as a condenser and a ribbon. To change the tone to make it fit better in the track, try swapping the mics to see if the sound works better.
One last thing to think about with recording separate parts of the guitar. If you only have one high quality mic, try to put place it in the most important position, which is usually the neck/soundhole. By letting the quality mic capture most of the sound, the other mic can then be placed on the body to complete the overall sound.
Technique #2 - Close And Ambient Miking
Another technique that uses more than two microphones involves placing a mic close to the guitar and another in the room to record the ambience (see Figure 5). The first mic is placed at the usual fretboard/soundhole position near the body to capture the direct sound of the instrument. The second mic is used to capture the ambience of the room and should be placed at least three feet further away from the first mic (out in the room) to maintain proper phase integrity. This technique depends upon the quality of the room and the actual amount of room space that’s available.
A three microphone technique is especially effective for solo or duet guitar pieces, as it offers a wide array of tonal options when it’s time to mix. It also can provide an exceptionally wide stereo image if recorded in stereo.
Three Mic Technique #1
Place a single mic at the soundhole/neck position and then place a pair of omni or large diaphragm mics several feet back from the guitar (at least three) and several feet apart (again, at least three - see Figure 6). This creates a virtual ‘triangle’ of sound, and it’s especially effective in a good, reverberant studio space.
Three Mic Technique #2
Recording the acoustic guitar in stereo can provide a lush, deep soundfield that can really add to a mix. Another recording option is to take an X/Y pair of mics and add a single room mic (see Figure 7). This method creates an amazing sense of space and depth, as the stereo pair captures the up-front direct sound of the guitar, while the second mic captures the distant ambience.
There are a couple of other rather simple miking alternatives to consider that can be perfect under certain conditions.
A good stereo microphone will accurately reproduce not only the left/right signal, but also front to back depth. It also a great choice when recording a pair of guitar players that are performing at the same time. Depending on the physical placement of the mic, the localization of each player in the soundfield will be determined by how close each is to the microphone as well as how loud they play.
It’s important to remember that when using a stereo microphone, it’s basically point and shoot, since both left and right capsules are built into the same body. Therefore, you need to make sure your placement on the guitar is correct, and that the depth from the instrument allows for the desired amount of ambience. Once again, the best place to start is where the neck meets the soundhole and move it from there as needed.
Clip-On Or Miniature Mic
The advantage of clip-on microphone like DPA’s supercardioid 4099G is that it remains in one position no matter how the guitar sits, so it takes a lot of the guess-work out of microphone placement. The mic is typically mounted to the guitar with a clip that allows you to place the microphone near or above the soundhole/neck position (see Figure 8).
If the player moves around a lot while playing, a clip-on mic can keep the sound more consistent because it moves with the player. It also very effective if you’re both playing and recording yourself, because the positioning is always perfect. You’ll find that a clip-on mic can also come in handy when recording a jumbo body guitar that may have to be propped up on the player’s knee to accommodate a comfortable playing position.
This concludes our series on getting the best guitar tone possible. Unfortunately it’s only touched the tip of the iceberg as they’re so much more to talk about. There’s lots of great information available on Web, but there’s also a lot of bad information too, so be careful. Of course, you can always check out The Ultimate Guitar Tone Handbook to help you on your quest for the ultimate tone. Above all, don’t be afraid to experiment, and don’t just place the mics, open your ears and listen.