PLUGGING INTO "UNPLUGGED" SOUND

An acoustic guitar­playing singer songwriter's guide to natural onstage tone

BY EMILE MENASCHÉ

It’s a cruel irony that the acoustic guitar, blessed with a unique com­bination of portability and usefulness as both a solo and accompa­nying instrument, can lose so much of its character when amplified. The complex tone created by the vibrating top as it interacts with the body has always been hard to capture, even in the studio. Fortunately, acoustic guitar amplification has come a long way in recent years. Here’s a quick guide to choosing and using the latest pickups and processors

Pickups

Acoustic guitar pickups fall into three main categories: magnetic pickups, which read string vibration in muchthesame way aselec­tric guitar pickups; contact pickups, which read the vibration of the instrument itself, either at the bridge, the top, or both; and

onboardmics,whichmountonorinside the gui­tar. Several of the more sophisticated systems are hybrids that combine two or more of the above.

Magnetic pickups have been around for a long time, and early examples were thought to sound less natural that mics or contact pickups. But many of the latest models have been tuned to offer what—for lack of a better term— we’ll call a “woodier” sound.

Models that clip on or use friction to stay in place in the guitar’s sound hole—such as the Dean Markley Pro Mag Plus (also available as a humbucker), the Seymour Duncan SA­3SC Hum­Canceling Woody, and the DiMarzio Super Natural Plus—are especially appealing if you have a pure acoustic and don’t like the idea of permanently installing electronics. Only slightly less flexible are magnetic pickups that are held in place with screw­down clamps, such as L. R. Baggs M1 and Fishman Rare Earth. These stay secure, but can be removed in fairly short order.

You also have the option of a more permanent attachment, with the output going through the guitar’s end pin. Note, however, that smaller guitars and instru­ments with non­standard sound holes may not be able to accommodate all pickups. Check the size before you buy!

Many—but not all—magnetic models are pas­sive, meaning they include no electronic tone controls, and therefore don’t require battery power. Some models have adjustable pole pieces, allowing you to tune their response for each string. Another plus: magnetic pickups resist feedback very effectively.

On the downside, some players complain that the pickup’s focus on the string sound comes at the cost of body resonance and that the pickup’s position on the top impedes vibra­tion. Fortunately, magnetic pickups are easy to audition on your own guitar, so you can hear for yourself how each pickup’s tonal character matches your instrument.

Contact pickups were once only stick­on affairs, and compact and versatile transducers such as the DiMarzio’s DP130 are still available. It can be affixed anywhere to the guitar’s top using removable putty.

But much more common these days are piezo transducers like the Fishman Acoustic Matrix and L. R. Baggs Element, which reside under the bridge saddle. Standard on most off­the­shelf acoustic­electrics, a piezo can also be retrofit with minimal drilling. If you already have a piezo­equipped guitar, you can usual­ly switch or upgrade to another model with­out making major modifications to your axe.

A piezo doesn’t impede the top’s vibration, can’t be knocked out of place, and its position in the bridge ensures that it captures plenty of high end. But some models can sound stri­dent and don’t do a good job of capturing the resonance of the body.

Many systems that include piezo pickups require batteries (or phantom power). But the juice is typically there to power an onboard preamp and not the pickup itself, so you can install a passive piezo and run it directly into an amp or outboard preamp if you don’t like the idea of mounting a battery inside your guitar.

In the last few years, manufacturers have moved beyond the saddle to develop multi­transducer systems that capture vibrations at various points on the guitar’s top. Taylor’s Expression system uses a trio of underbody sensors along with an under­fingerboard pick­up. Multi­contact pickups are also available as retrofits. K&K Sound’s Pure system uses an array of body sensors in combination with a piezo. L. R. Baggs’ iBeam sits under the bridge plate, and, like the K&K, comes in both passive and active models. B. Band’s soundboard transducer can be applied to the underside of the top. The D­TAR Perfect Timbre DPU­3 can be positioned under the bridge and comes with a preamp.

But while pickups continue to advance, some players feel that only a mic can capture the most natural sound. DPA makes a wide range of standard and clip­on mics, including the 4099GTR, which can be mounted with one hand (for quick changes). It can also work with other stringed instruments.

More common, however, are-in-the-bodymics-which are often used in combination with contact and/or magnetic pickups. The Matrix Blender is one of several Fishman sys­tems that combine an internal condenser mic (mounted on a gooseneck so that it can be repositioned) with a preamp that can mix in the sound of a transducer. K&K’s Trinity sys­tem comes in several different versions (including one optimized for nylon string gui­tar). B. Band systems can also include mics.

These hybrid systems perform extremely well, but they can also require a little extra fiddling onstage. The internal mics do a nice job of adding body and depth to the sound when mixed with transducers, but can sound somewhat hollow and uneven on their own. Internal mics can be prone to squealing feedback, depending on where you play in relation to your monitors (Be especially careful when leaning down to adjust an amp—yowl!). Finally, the mics can pick up body noise and singing. That said, the ability to ajust the blend between the mic and the transducer gives you more con­trol over your tone onstage; for example, you can bring in more mic to capture the warmth of a finger­style piece or use more of the contact pickup if you want to strum intensely with a rock band.

Processing

As acoustic pickups have become more nat­ural sounding, sound­shaping preamps and processors have followed suit, giving players even more sonic possibilities.

Whatever kind of pickup you’re using, a good preamp is essential if you want to have control over your tone. As we alluded to in the section above, preamps can either be mount­ed on the guitar or contained in outboard devices. Most of the leading pickup manufac­tures, including Fishman, L. R. Baggs, B. Bend, K&K and others, offer onboard preamps, and several make outboard versions, as well.

Years ago, almost all onboard preamps were mounted on the side of the guitar; this required cutting a fairly large hole in the instrument. Now there are other options, including soundhole­mounted preamps, which can be installed and removed with min­imal harm to the instrument (controls are also closer to the picking hand); preamps built into the endpin with remote controls, and permanent mount systems where the only holes added to the body are for the con­trol knobs themselves. Dean Markley’s Trilogy system combines a bridge piezo with a soundhole magnetic pickup that also houses a mic and preamp—a relatively easy retrofit.

Outboard preamps are also available, and can be really useful if you’re planning to run a passive pickup through a P.A. system. Many of the leading amplifier and effects processor companies now make analog and digital pre­amps just for acoustic players. Note that you may not need a preamp at all if you’re plug­ging into an amplifier designed for acoustic guitar, as its built­in circuit may be equipped to handle both passive and active pickups.

No matter which kind you use, a good preamp should include both tone­shaping EQ and a notch filter to help tame feedback. Some models also include a phase switch, onboard compression, built­in tuners, addi­tional mic inputs, and other processing. A device that offers both balanced XLR out­puts and unbalanced instrument outs is espeially handy if you gig in a lot of different environments.

Digital technology is playing more of a role than ever before in acoustic guitar tone. Standard effects like reverb, delay, and cho­rus are common—and are often included on acoustic guitar amplifiers and preamps.

But microchips can also be used to shape the tone of the guitar in ways that go beyond mere sweetening. Fishman’s Aura, which is available both as a standalone outboard device and as an onboard preamp, is designed to model the sound of a miked guitar (the technology is sim­ilar to electric guitar processors that digitally recreate the sounds of vintage amps). A “virtual mic” can be blended with the output from the guitar’s analog electronics, and the result can be very impressive. In addition, systems like the Aura and the Seymour Duncan|Turner

Acoustic Systems Mama Bear can simulate the natural body resonance of specific instruments; the technology is intended to transform the sound of one type of guitar (for example, a dreadnought) to that of another (say, a concert sized model).

Inside the Box

So, how do you put these tools to good use? Start by thinking of the electronics as one sys­tem. If your guitar has a built­in EQ and you’re going into a preamp with an EQ, consider leav­ing one of them flat, so you’re not over pro­cessing the sound. If you playwithwide dynam­ic range, use a compressor, but try to keep its effect subtle, so that the guitar doesn’t sound squeezed when you hit it hard. Take control: If you’re feeding the house system, tell the engineer how you’re setting up your preamp. Move around the stage during sound check to make sure there aren’t spots that cause res­onant or micrphonic feedback.

And practice at home: The more you get to know about how an acoustic guitar’s pick­ups, preamp, processors and amps work together, the more control you’ll have of your sound onstage.