Recording Outside the Box

Jun 14, 2005 6:21 PM, By Pat Kirtley

           
 

Omnidirectional mics are totally free of this bass-boosting aberration, and when you can use them, the open, airy quality can be striking. Most people don't think of omni mics when recording acoustic guitars because they pick up more reflected room sounds than the directional types do. However, since they are free of proximity bass-boost, you can place them closer to the instrument and maintain a good balance between guitar and room (see Web Clip 3).

It's a habit to deploy a stereo mic pair to record acoustic guitar. But the stereo concept itself, as exemplified by a left-right speaker pair, is overrated in my opinion. At no time does the recordist have any control over the listener's speaker setup, which may be anything from an audiophile listening system to a cheap boom box to headphones. A stereo image that sounds crisp and spacious in the control room is sometimes blurred at end-user playback.

Summing a stereo pair to mono, especially with acoustic guitar as the subject material, can bring potential foibles to light. But there's a technique that often reveals sonic truth for all to experience: just use one mic. Doing so can be tricky, because it forces the recordist to find the precise distance and angle that will yield the best balance. But once the spot is found, a single-mic perspective can give a track a satisfying “already mixed” quality.

If you're afraid to commit, try this compromise: record a stereo pair of tracks as usual, but add a third (mono) mic on its own track and compare the two versions. You might be converted to this underused method. If you need more convincing, listen to some late '50s to early '60s, one-mic, classical guitar recordings made before stereo was popular. Do you have only one high-quality condenser tube mic that you usually reserve for recording vocals? Try it on guitar.

Recording directly from an acoustic guitar's built-in undersaddle pickup system rarely yields pleasant results. The sound tends to be strident and one-dimensional. Taking a cue from the late, legendary guitar master Chet Atkins, consider plugging into a guitar amp and miking it.

What might seem like the ultimate heresy to the purist camp was Atkins's preferred method when he recorded his acoustic-electric nylon guitars. And he didn't use one of those new-fangled clinically accurate “acoustic” amps either — his choice was more likely a tube amp made for electrics, typically his vintage Standel with a single 15-inch speaker. His mic of choice was either a Neumann U 87 or an old RCA 44DX ribbon.

Synthesis and MIDI are basic components of keyboard setups, but they are not as commonly associated with guitar, especially acoustic guitar. Indeed, many people would consider the electronic tones of a synthesizer to be the antithesis of the pure, organic sound of an acoustic. I've found, however, that you can create lots of cool new tonal possibilities by using the synthesizer's tonal palette to embellish that of the guitar when recording.

A simple way to bring synth capabilities to your acoustic guitar is to equip it with a synth pickup. For example, you can mount a Roland GK-2A (temporarily) on your guitar, enabling your instrument to drive a compatible synth and giving you the means to record simultaneous synthesizer and acoustic guitar parts.

FIG. 3: The method shown here involves miking an acoustic guitar that's equipped with a synth pickup. The pickup drives a synth module whose output is routed separately to the multitrack, where it serves as an ethereal "ghost" track to supplement the main guitar sound in the mix.

A particularly effective approach is to set up the synth with a string patch or slow-attack sample that “follows” the guitar with orchestral lushness (see Fig. 3 and Web Clip 4). Depending on how the mix is done, it can be a subtle background that blends into the reverb, or a thick sound that stands independent from the guitar tone, as if a keyboardist were playing along. Another cool trick is to feed the synth pad to the reverb send during the mix, but mute the direct sound of the synth track. The resulting reverb effect (which the ear interprets as originating from the guitar) can range from airy to otherworldly.

Many recording setups, computer based or otherwise, allow you to record MIDI data in sync with the audio tracks (if you're using the GK-2A, you'll need to plug into a GK-compatible synth or interface in order to get a MIDI out). By recording the MIDI data generated by the guitar synth, you create a trigger track that can drive synths in a number of ways during mixdown, widening the spectrum of possible tonalities and choices immensely.