Short on $10,000 microphones to record guitars? Then start here…
By Darwin Grosse
In this article, we are going to take a “guerilla” approach to guitar miking techniques, using a small (but versatile) set of inexpensive microphones. It might be easy to discuss guitar recording in a vacuum, and I’m sure you could buy a $10,000 Neumanleyfunken microphone, glue it to a tree, and get an excellent guitar sound. However, most of us have budgets, often kept very tight, and getting a good guitar sound with a limited mic collection is a necessity.
These days, the budget microphone class is really quite amazing. When I began recording (back when Giant Lizards roamed the earth), a decent condenser microphone cost two months’ pay. Now, you can get both a large-diaphragm and a small-diaphragm microphone for less than the cost of dinner for four at a decent restaurant. So, assuming we are willing to stay at home for a few weekends, we can probably scrounge up a budget for a decent mic “cabinet.”
Using a theoretical budget of around $500 (your mileage may vary, depending on how patient you are in waiting for sales and the like), I assembled the following microphone setup:
- An MXL “combo” with two condenser mics, one large-diaphragm (the 2001P) and one small-diaphragm (the 603S)
- 2 Oktava MC012 small-diaphragm condenser mics, with cardioid capsules
- 1 Shure SM57 dynamic mic
- 1 Behringer ECM8000 omnidirectional “measurement” mic
- 1 Behringer Ultra-DI box
- 4 mic stands
- 5 microphone cables
- 2 pillows and a blanket (I didn’t buy these—I took them off the bed!)
By scouring the sales rack, looking for used microphones and borrowing your Uncle Howard’s mic stands, you can probably trim this budget even tighter. In any case, we will use these tools for an attack on guitar recording.
Frontal assault on electric guitars
Everyone knows how to record an electric guitar—you slap an SM57 in front of the amp and hit Record, right? Well, that isn’t always the best plan, but it can be a good start. The trick is to find a “sweet spot” on the speaker, and set the mic up to capture that sound.
Generally, the center of the cone won’t be a great spot for the microphone, since you can get some funny artifacts from the entire speaker pounding on both the mic diaphragm and body. What I’ve found most useful is to place the microphone off-center, then to adjust the nose of the mic until it is pointing at the best-sounding part of the speaker cone.
In the case of my Line 6 Spider amp, it turns out that the best sound is found around one-quarter of the way across the speaker. The best way to find the “sweet spot” is to have someone play the guitar, and move the mic around while monitoring the mic with a good set of sealed headphones. (In fact, one of the most important items for good guitar recording wasn’t listed in the above kit; that is, a really long headphone cable.)
In some cases, and especially for less aggressive music styles, adding a second microphone will help add “air” to the sound. Using the large-diaphragm MXL mic, I add a bit of the room sound so the cabinet is able to “speak” a little before the sound is captured. By balancing the close and distance mics you can get a variety of sounds that will help a guitar sit better in a mix, but it doesn’t take much. In a recent recording I found that having the ambient mic at –15 dB (while the close mic was at 0 dB) gave just the right amount of presence without adding an obvious roomy sound.
The use of a second, ambient mic is especially useful with jazzy guitar sounds, and almost a must when doing funky wah-wah tracks. However, you need to watch out for phase problems between the two mics; if the result of mono-summing the mics sounds like a phase shifter stuck in one spot, you have to do a little more work on placement. Generally, moving the ambient mic a few inches in or out will greatly improve the sound.
Multi-speaker cabinets are a bit more challenging. This takes more experimentation with placement while wearing headphones. Get a mic in front of the cabinet, and try out the different speakers—you will generally find that one of the speakers is the “beauty,” and you will want to focus on close-miking that one. As for distant mic placement, you will probably want to move the mic back; a Marshall stack takes a little more distance to fully form its sound than a Fender Champ does. I’ve had situations where a loud player will be ambient-miked as far as 8 feet away!
If you want a clue about good ambient mic placement for an electric guitarist, watch where the player likes to stand while warming up and noodling about. Guitarists tend to, unconsciously, gravitate toward the spot in a room where the amp sounds best. Let the player noodle for a while, then drop a mic in that spot and have him go stand in the corner (where he probably has belonged since grade school).
If you want to get creative, use a DI (direct injection) box in addition to the amp output. This can really help a guitar stand out in a mix, especially for those guitar arpeggios in the middle of a power ballad. The addition of some DI “tink” on top of the cabinet’s roar can help focus the sound when the instrument is exposed. If you get creative during mixdown, you might even find the direct sound is a great source for some reamplification. (And if you want to learn more about DI and reamplification, check out my article here.)
Flanking the acoustic
The recommended arrangement for the stereo recording of an acoustic guitar is to use a pair of small-diameter condensers bunched around the 12th fret. As with the “classic” electric technique, this is a great starting point for a guitar recording. However, in some cases, we need either a lighter touch, or more ambience in the sound, since this standard technique tends to have a very up-front quality that might not fit well for all recordings.
One mic layout that I like is a single small-diaphragm condenser combined with either an omni or cardioid mic over the player’s shoulder. This doesn’t have the clear stereo nature of the dual close-miked sound, but it has a more delicate sound than pure close-miking, and has a great focus point for panning in a complex mix. As with the near/far mic combo for electric, you don’t need to have copious amounts of the distance mic in the mix; often, a small amount of ambience (as little as –15 dB) will give depth to the mix that a reverb effect can’t match. Also, if you pan the mics a bit in the stereo space, you can get a very “player-friendly” sound for an acoustic solo recording. This technique is especially effective if you have a good-sounding live room in which to record.
The 3-to-1 rule
Recording wouldn’t be the tweak-science it is without a bunch of rules-of-thumb. One of the most useful rules is called the 3-to-1 rule of microphone placement, which suggests that if a microphone is x distance from the source, other microphones need to be a distance of 3x (or more) from the first mic. For example, if your close mic is 4 inches from a guitar, your second mic should be at least 12 inches from that mic. This will help alleviate the worst of phase problems, and will make your mic placement problems much less severe.
Of course, as with any rule, there is an exception. If you are able to set up the microphones to get the sound wave at virtually the same point, you should be able to avoid phase issues. This is why the dual close-mic technique works—the two microphones are getting the sound at essentially the same point, and phase cancellation will not (usually) be a problem.
As with any recording technique (and any rule), experimentation is important for each situation you encounter.
For the most delicate sound of all, I replaced the small-diaphragm Oktava with the large-diaphragm MXL and started playing around with distances between mic and guitar body to get a good balance between the mics. By focusing up the neck, I caught plenty of the body without boomy soundhole “blow.” The player was doing some smart fingerpicking, and this setup provided a smooth and warm sound with just the right imaging.
Dealing with acoustic guitar ambience is a lot more difficult than with an electric—the sound of an acoustic won’t overwhelm a room like a guitar amp can. This is where the pillows and blanket come into play. By draping a blanket over a mic stand, then altering the distance between it and the microphones, you can alter the effect of the room without eliminating the ambience completely. I will often place the blanket on the body side of the acoustic, relatively close to both the instrument and the mic. This seems to tighten up the sound without making it sound like I recorded the track in an anechoic chamber.
I tend to use pillows to control floor reflection. One pillow placed in the spot of the first floor reflection (halfway between the player and the distance mic) will help sweeten the ambience quite a bit; a second pillow placed just in front of the player’s feet will help prevent too many “splashy” early reflections. The pillows can also be used to alter the response of an omni mic—for example, having a low-mounted omni with a pillow underneath can give you a rich sound without sounding totally reverberant.
In situations where I want a very wide stereo sound, I’ve “split” two microphones using the blanket-on-a-stand. This will force the ambient sound to remain separated left-to-right, and will create an incredibly wide image without the in-your-face sound of close-miked condensers. If you are double-tracking the guitar, try using the left side of one take and the right side of the other—the results will either sound great or threaten to twist your head off.
One of the more difficult guitar recording chores (for me) is getting a good 12-string sound. Perhaps it is because of the instrument I use—a cranky old Fender 12-string with a body shellacked as hard as a rock, but with a good feel. I’ve found that the harsh harmonics of the instrument, combined with a rather honky body sound, make it difficult to get a full yet natural sound.
One thing that I find very useful in this situation is using a soundhole-mounted pickup to get a little clarity in the sound. Using this pickup along with a small-diaphragm mic pointing toward the 12th fret tends to work for most applications. Interestingly enough, I found that using the large-diaphragm condenser for ambience, mounted over the player’s head and pointing down, gives a more natural sound than one in front of the instrument. I’ll also use the blanket and pillows in this application for a little “splash control.”
When you have a modest mic collection, you often have to be more experimental with placement than someone with a brimming mic locker. Better-quality mics can make a difference; they generally have a better sound “out of the box” and provide more flexibility with placement.
But as guerilla recordists we have to make compromises due to budget concerns. One important factor is where you do the recording. As with real estate, one of the keys to good recording is “location, location, location.” Every condo, apartment, house and studio will have a few spots that are perfect for recording. Spend some time tracking those places down, and you will find that your tracks just sound better. The key to great guitar recording boils down to having a good combination of mics, a good ear, and plenty of time for experimentation.