Tips, Tricks, & Techniques

(Tips, Tricks, & Techniques provides how-to information about folk music and other topics. The main Tips page contains a list of additional tips.) TO PLUG OR NOT TO PLUG . . . IN, THAT IS? Microphone or Pickup? Remember when acoustic was acoustic and electric was electric, and never the twain did meet? Didn't think so. Ever since Bob Dylan horrified the folk establishment by "going electric" at Newport back in 1965, electrical amplification of instruments (even acoustic ones) has become a fact of folkie life. Nowadays, when we use the term "acoustic music," we're tempted to define it "as opposed to optical music." The consensus definition of acoustic music today is: music played on instruments that were designed to be played unamplified—or at most merely mixed. Truth is, much if not most of the time when these instruments are played on stage or in the studio, Mother Nature gets more than a little help from Reddy Kilowatt. So you can guess the answer to the title question. These days, the only way to have your instrument heard above the crowd and as loudly as your voice (without feedback and with some degree of freedom of movement) is to amplify it. But how? There are two basic ways to make the sound of an acoustic instrument loud enough to be heard clearly despite all other variables: microphones or pickups. (Both are transducers—devices that turn vibration energy to electrical impulses and back to perceptible sound.) The most time-tested device, and the one favored by venues that only grudgingly allow amplification at all, is the microphone. (We'll save a discussion of the difference between dynamic and condenser mikes for another article.) The most common type is external, positioned close enough to the soundboard (or even freeboard) of the instrument to reliably reproduce the signal, but not so close as to get in the way of the player's hands—or so close to the soundholes that it produces feedback. Within the past twenty years, microphones have become sufficiently miniaturized to be placed within the instrument itself—usually just inside the soundhole facing out, thus amplifying the signal without causing feedback and staying totally out of the way of the player's hands. This type of microphone is usually employed in tandem with a piezoelectric pickup, powered by an onboard battery, with the jack for the cable incorporated into the endpin for the strap. Needless to say, this setup is far more expensive than all but the costliest external condenser mikes. And in most cases, such a system is not only messy to retrofit to an existing instrument, but also possibly detrimental to both the integrity (and possible later resale value) of the instrument. Therefore, these blender types of systems are usually factory-fitted to an instrument as original equipment. Fishman's Blender Prefix system is the best known and most widely used. A pickup also senses, converts, and transmits sonic energy, but senses it from some portion of the instrument itself; whereas a microphone senses this energy via vibrations in the air adjacent to the instrument. So what's better, mike or pickup? It depends on your needs as a performer. If your aim is to most accurately reproduce the sound produced by the structure and tonewoods of the instrument, only louder, miking is the way to go. An external mike is easier to adjust and reposition for various nuances in sound, but it does hamper mobility—get too far away and you lose signal, get too close and you're in danger of feedback. An internal mike eliminates the distance factor (and the bumping-into-one's hands factor), but it's usually costlier due to miniaturization, needs preamplification, and is more difficult to adjust. A pickup sacrifices true "wooden" sound (but not by much these days as pickups are getting more accurate by the minute); however, both pickups and internal mikes let you move about the stage as far as your cable length will let you. For most purist coffeehouses and excellent acoustic environments (churches and halls with killer PA systems and folks who know how to run them), as well as in the studio with a good engineer, go with the mikes—especially if onstage mobility is not an issue. But these days, unless you play only coffeehouses, most venues you encounter will require both mobility and conveniently controllable volume. A pickup is also necessary if you employ any signal processing (which devices will be explored in a later article). You would do well to have a pickup in a quality instrument whose character comes through when using a mike alone. What Kind of Pickup? I briefly mentioned piezoelectric pickups earlier. Let me distinguish them (sometimes also known as contact or undersaddle pickups) from the earliest type of guitar transducer—the magnetic pickup, still the nerve center of the modern electric guitar. Piezo pickups are based on tiny ceramic crystals that are excited by vibrations transmitted to them and that then convert the vibrations into electrical impulses (which are in turn sent to the amplifier and turned back into sound). In guitars, they are most commonly mounted beneath the bridge saddle abutting the bridge plate. In such a position, they sense the vibration transmitted from the strings to the bridge plate and then to the wooden soundboard. They can also be contact sensors, mounted on the outside of the soundboard itself; these literally transmit vibrations from the soundboard . Contact pickups are the easiest and cheapest piezos to install, as there is usually nothing to drill. (You use removable adhesive to hold them in place.) The disadvantages are twofold: first, finger noise as well as musical vibrations are transmitted; and second, the sound is never as natural as that produced by an undersaddle pickup. Undersaddle pickups give a more natural sound (and blended correctly with microphones—as natural as an amplified sound can get). Piezo pickups are can be passive (transmitting signal without boosting it beyond simple reproduction) or active (amplifying the signal even before it gets to the amplifier). You've probably guessed that the signal emanating from an active pickup is more powerful; you've probably also guessed that active pickups are usually more expensive. Both can be either factory or aftermarket installed. But unless controls are already built into the instrument, both need at least an outboard control box. A passive pickup also requires a powered preamp (which usually incorporates tone and volume controls). Active pickups must be powered, usually by a battery. The installation includes a well-concealed place for a battery (and in the types of instruments with controls, that place is usually within or adjacent to the control panel). They give a stronger and more accurate signal, and both types of pickups are most versatile when connected to onboard or outboard volume and tone (EQ) controls. Fewer manufacturers these days offer passive piezo pickups for undersaddle mounting; they are most often found in instruments where onboard battery installation is difficult or impossible—mountain dulcimers, f-hole mandolins, and the like. The best and most commonly used passive piezo pickups these days are made by L.R. Baggs. (In the past, Barcus-Berry was the most famous name in contact piezo pickups, and Martin/Shadow "Thinline" the most popular undersaddle passive piezo.) A pioneering passive undersaddle piezo was Takamine's "palathetic" system, still in use today in both passive and active versions. The most popular and effective active pickups are usually the Fishman Matrix (which, though already preamped, needs an outboard box for volume and EQ control), the Fishman Prefix (which has volume and EQ controls onboard), the Baggs LR-6 , and the Fishman Blender, which mixes the pickup's signal with that of the internal mini-mike and lets you control the proportion. The Baggs and Matrix are usually installable without cutting into or modifying the instrument beyond (perhaps) a new saddle; the Prefix and Blender are usually factory installed, as they require cutting a hole into the side of the instrument to accommodate the control panel and battery. The Prefix is also offered by a number of guitar-makers under their own proprietary names. What do I use? My 20-yr-old Martin has a Fishman Matrix plugged into either an outboard preamp-control box (with the switch set to active) or an acoustic guitar amp with the switch also set to active, depending on whether I need to bring my own amp. My newer Martin cutaway has a built-in Fishman Prefix system and my Taylor maple cutaway a Fishman Blender—no external box necessary for either (unless you want to go into the "balanced" XLR connectors of the house PA or amp, in which case I get a "direct box." (See the upcoming "toys" segment.) My McSpadden baritone and Blue Lion Model I dulcimers have passive Baggs undersaddle pickups; my Blue Lion Model II has a custom-built Fishman matrix with external battery box (which in turn plugs into a control box). My McSpadden Ginger (soprano) dulcimer is usually amped by a passive Barcus-Berry stick-on piezo—it came to me sans pickup. And I have been fooling around with a solidbody electric dulcimer fitted with a single-coil magnetic pickup by its builder. So should you use active or passive? If you want to use an acoustic guitar amp or a preamp with its own booster and volume controls, a passive pickup will do just fine. But in noisy bars or quirky sonic environments, you can't beat the advantage of an active pickup with onboard volume and EQ controls. Also, you can modify the instrument's sound more freely with onboard EQ—especially if you want to alter the sound of your guitar's tonewood—up to a point. If you don't mind multiple cables and dangling "toy boxes," then a passive pickup plus a preamp/direct box gives you the most control—analogous to switching from an automatic camera to a good ol' fashioned Pentax K1000, which lets you change settings manually. What's a "Magnetic" Pickup and Why on Earth Would I Want One on an Acoustic Guitar? In contrast to piezoelectric pickups, magnetic pickups are charmingly archaic—or so conventional wisdom held until recently. Advantages are ease of installation and removal. (The original Dean Markley, Shark, and Fishman Rare Earth all fit into the soundhole, spanning its diameter.) Magnetic pickups are generally, well, magnets. There are as many little metal dots ("poles") as there are strings on the instrument, and the little dots sense the magnetic vibrations of the strings alone. They can be quite loud and lend themselves to acoustic rock-and-roll. But they hum like crazy in the presence of electrical interference and can be used only with strings that have enough steel in them. Until recently, the sound was fat and one-dimensional, making it possible for your prewar Martin D-41 or super-premium Santa Cruz or Collings to sound like a $200 Yamaha. (In the mid-Sixties, John Lennon used a Gibson maple sunburst dreadnought with a magnetic pickup and built-in volume controls.) The newest mag pickup, the Fishman Rare Earth, clamps into the soundhole and provides a very true sound. The cable can either be routed through the strap button for a more permanent installation or left to dangle outside the soundhole for removability. My main quibble with it was, despite the gorgeous tone, it hummed at 60 cycles—the very frequency beloved by neon and flourescent lights. (Some day, some engineer will sample a 60-cycle hum, and process and loop it into a terrific hip-hop dance tune.) Early electric guitar manufacturers addressed this problem by making humbuckers: dual-coil pickups with the poles positioned against themselves in such a way that the magnetic impulses, and thus hums, cancel out each other. The Rare Earth humbucker now comes in a fairly expensive humbucking version (more than $150 for the 2001 model, assuming your dealer can keep it in stock). I have heard good things about it and have heard even better sounds coming out of it. In my opinion, this is the way to go if you have an insanely expensive or vintage acoustic you wouldn't even breathe askance on, much less modify. So the advantages of a mag pickup over a piezo are twofold: first, it's louder; and second, it's a mar-free way to amplify. The disadvantages are that infernal hum and a less natural sound. The sad fact is that today, unless you're playing an intimate house concert or party, you need amplification. Whether you plug in a mike or a pickup, you can make yourself heard—or not, as the mood strikes you. That's what I think. Your mileage may vary. Main Page • List of Tips • Contact Sandy Copyright © 2000, 2001, Sandy Andina, All Rights Reserved