Acoustic Guitar Miking Techniques: How to best capture the natural sounds of an unplugged six string
By Edward Gerhard
The guitar that I played on Luna was built by Ervin Somogyi (Berkeley, CA), and it is a very unusual-sounding guitar. I think that’s one of the things that contributes to the different sound of Luna. A lot of guitar records you hear are very crisp, crystalline, and bright. This guitar has some of those characteristics, but it also is very round and thick-sounding, almost like a nylon-string guitar. And that is the texture that I wanted to capture on these records.
I recorded the pieces for Luna in a couple of different rooms. One room was fairly large with a high ceiling. The other is a relatively small, rectangular shaped room – basically an extra bedroom in my apartment. Both rooms were rather dead acoustically and that, along with close-miking, helped to keep the guitar sound consistent.
Ninety percent of the basic guitar tracks were recorded with a pair of Neumann KM 140 cardioid condenser microphones through a Mackie MS1202 mixer. This was before I got my Alesis ADAT, so I just used the Mackie mic pres and recorded the guitar in stereo straight to a Panasonic SV-3700 DAT machine. On a couple of songs those stereo guitar tracks were bounced over to an ADAT so that we could add overdubs. While a lot of songs on the CD were just solo guitar, there was some overdubbing. On a few tunes I played a second guitar and on other tunes there were trumpet, upright bass, or drum overdubs. For those purposes we transferred straight into an DAT using the analog input and I didn’t feel like there was any loss in the transfer. If I had heard any problems or differences in the audio I would have tried something different. I tried to be as meticulous as I possibly could where the audio was concerned – I listened very carefully to the transfers and they didn’t pick up any noise and I didn’t hear any generation loss.
I used two Neumann KM 140’s to mic the instrument and I placed the first mic on the neck at about the 18th fret. Sometimes it was pointing straight in at the neck and sometimes I would angle it a few degrees. If I was getting a lot of string noise I would face it slightly away from the neck and point it more towards the sound hole. Or if I could hear myself breathing, I would angle the mic down a little bit towards the guitar. But it was pretty much an-axis and no more than six inches away from the neck. The second microphone was in a sweet spot just behind the bridge, pointing basically straight in at the soundboard, and occasionally, I would move it slightly off-axis.
I wanted a really big guitar sound, but I have heard many guitar records that have an almost exaggerated degree of intimacy to them, which I didn’t want. I wanted to go for the “cinematic” approach to the guitar sound where it would be filling the entire frame but it wouldn’t be in your face. Each of these mics was recorded to a separate track (panned hard left and hard right) and they stayed panned in exactly the same position through the mixdown.
The microphone near the bridge area was also about six inches away, and I think it’s important to keep the mics pretty close to the same distance away from the guitar. Otherwise, you will start having phase problems because the amplitude in different areas of the guitar is going to be different. I listened really closely for phase cancellation and if there were any problems with phase, they were very minor. My way of thinking is that unless the sound is totally collapsing in mono – for an acoustic guitar to record – you are generally pretty safe. Acoustic guitar records are not getting played on hit radio stations so you don’t have to worry that much about what it will sound like on somebody’s clock radio. I would sacrifice a little bit of phase coherence for a killer tone.
A HINT OF EFFECTS
The only time I processed the guitar was during mixdown where I would add a touch of reverb. I used a bit of Lexicon PCM 70 on most of the tunes – sometimes for a little ambience, sometimes for a wetter reverb. On pieces like “Luna” and “Howl,” I knew I’d be using a bit more reverb than on the other songs, so I increased the distance between the mics an d guitar when I recorded them. To me, a tightly miked acoustic guitar swimming ina big spacious reverb is an audio oxymoron. The presence is fighting with all the space you’re trying to create with the reverb. Back off from the mics a little (even two inches can make a big difference) and the reverb sounds more real.
During the mastering stage we did not normalize or compress, although there were a couple of peaks I cut back so that the overall level of audio on the master tape could be raised. There was one brief bass note on “Red Mountain Serenade” that we trimmed with a little EQ. The guitar got a little bit thumpy during one particular passage so basically we punched the EQ button in, knocked the not back a couple of dBs, and then punched the EQ out for the rest of the song. Except for that one note there was absolutely no EQ and no compression. The sound of the Neumanns through the Mackie mic pres was exactly what I wanted.
My new CD will be called Counting The Ways (an album of all love songs) and I’m recording the guitar with a slightly different mic setup. I am using the KM 140’s again, but I have added a Neumann TLM 193. One of the KM 140’s is pointing straight towards the neck at around the 18th fret, but closer to the treble side of the fingerboard. The other KM 140 is raised up above the guitar a little bit, so that it’s basically about a foot over the sound hole for a couple of inches over the body of the guitar) pointing straight down towards the floor, at almost 90 degrees. The TLM 193 is positioned in between the to KM 140’s and points straight in so that the three mics sort of form a diagonal line together. The 193 is basically aiming at the sound hole and is placed just an inch or two further away from the guitar than the 140’s are.
Sometimes I’ll angle the TLM 193 inward a couple of degrees, depending upon how much life there is in the strings. If I start hearing a lot of overtones, then I’ll angle the 193 more towards the wood and away from the strings. Each of these mics is recorded to a separate track on my ADAT and when I mix, the KM 140’s are panned hard left and hard right and the TLM 193 is panned to the center. When I bring that 193 up, there really is a presence to the guitar. Oddly enough, now that I am working with both the KM 140 and the TLM 193, when I solo the tracks up in mono, the sound is absolutely phase coherent.
I’m also experimenting a lot with moving the 193 around, while keeping the 140’s where they are. The 193 sounds great everywhere I put it, and picks up the woodiness of the top very clearly when aimed at the sweet spot behind the bridge. I’m not using all three mics on every song for the new album, but when I am doing solo or duet guitars it sounds very cool. Where I’m using three or more guitars, the main and secondary guitars are miked in stereo with the additional guitars in mono because mono guitars are much easier to deal with in a complex mix. Quite often I’ll record the main, second and additional guitars in one sitting. I have all my guitars on stands around me. When it’s time to overdub I’ll just grab one, solo up each of the three mics along with the track to see which sounds the best without moving it too much and I’m there. In addition to my Somogyi, I’m also recording with a beautiful mahogany Breedlove – it sounds sweet and really cuts through. Too many tracks of the same guitar can sound like mush, so I like to give ‘em all a workout.