Source: Sounding Board Newsletter Vol 8 - February 2000
by Diane Ponzio
We all agree that our Martin guitars sound the best in a tiled bathroom or in the kitchen late at night, with our ear glued to the upper bout as we play. The acoustic sound of a Martin, pure and simple, is the best. It’s also the reason that when recording your Martin, whether on a home 4-track or in a digital 48-track super studio, a microphone is the best method to reproduce that fantastic sound. However, that sound is dependent upon the quality of the mic, the mic pre-amp, the mixing board, compression, and mic placement, to name just a few parameters.
By far the greater need is in amplifying a Martin guitar rather than recording it. Martin players will often play with a bassist, a drummer, a keyboardist, or other guitarists, and the need to be heard above other instruments and vocals necessitates amplification. Using a microphone to amplify your Martin is one, albeit, archaic method. Remember that mic-ing your guitar is a delicate science in a live performance setting. First, you have to stand or sit in just the right spot. If you boogie to the groove and move, you may lose your sound. The other problem may be feedback from overtones, ambient room sounds, or other instruments. Pick-up technology in the past 15 years has been evolutionary and revolutionary. The Martin Company decided long ago to pair itself with a leader in the science of sound transduction, The Fishman Company. Larry Fishman, an accomplished bass player, started out with a musician’s perspective coupled with scientific prowess. The results are state-of-the-art choices offering you varied and far reaching options. Your Martin guitar can be factory installed, or retrofitted, with anything from an under-the-saddle piezo pick-up, active or passive, to a magnetic soundhole pick-up, or even pre-amp systems that are built into the side of your guitar. This has more impact than you think — you are not tied into any one particular model; any Martin can be an acoustic/electric.
Pick-ups have a tremendous list of advantages: they are consistent, easy to use and understand, almost impervious to feedback, affordable, relatively easy to install, allow you to move all over the stage or playing area, and do not compromise the structural integrity or mar the cosmetics of your guitar. If you want fingertip controls, you can opt to select from a number of onboard or outboard preamp systems as well. For those players who still swear by a mic sound, there are "blender" systems from Fishman available for your Martin that provide a stereo mix of a soundhole gooseneck microphone AND a pick-up.
Let’s demystify this whole pick-up science a little bit. The true story is that in the 1800s, Madame Curie noticed that a ceramic crystal, when struck, emitted a spark. That spark was dependent on the pressure struck to the crystal. Six of these "Piezo" crystals, ("piezo" means pressure) when imbedded in a very thin piece of graphite and put under the saddle, approximate the same scenario. You strike the string, and the crystal underneath emits an electronic charge. That charge goes through a wire, out of the end-pin and through a 1/4" guitar cable to an amp or PA.
This kind of pick-up, a Martin Thinline®, is very percussive, but the signal is a "passive" signal. It’s raw. And what’s more, it’s high impedance. Impedance refers to the flow of electricity. If you think of it like a water flow, a garden hose is high impedance (MUCH resistance to flow) whereas a city water main pipe is low impedance (LITTLE resistance to flow). Amps and PA systems accept LOW impedance signals. Therefore, the Thinline pick-up necessitates what’s called a pre-amp. This unit, whether outboard or inboard, takes the signal, boosts it, and converts it to low impedance. Think of it as a holding tank, where you let the garden hose run water in, so then you can attach it to the water main. That’s when the signal becomes "active". My favorite combination is the Thinline with an "Active Jack." The Active Jack® looks like a small metal cigar and is inside the guitar, attached to the wiring, right before the end-pin. The circuitry on this is tiny but does a giant job of taking the signal from the crystals and making them ready for a PA system or amp. My favorite acoustic guitar amp, in fact, is a PA system. This allows for a terrific blend with vocals and other instruments through the board. "Active" pick-ups require a power source to do their job, and that is why you will always find a 9V battery mount inside the guitar, generally on the end block. The battery for an Active Jack®, for example, lasts about two years.
Another option is the active Thinline Gold Plus® pick-up. This transducer utilizes a continuous strip of copolymer material that behaves like ceramic crystals. Because the Gold Plus® is active, you don’t need a separate pre-amp. There are two varieties of GoldPlus® Systems available. The Natural I is for smaller coffeehouse venues, while the Natural II is for larger concert venues where a sound board (mixing console) is utilized.
This only scratches the surface. There are several onboard slider controlled "Prefix" systems available for factory installation. There is also a new line of "Rare Earth®" magnetic pickups with several options that mount into the soundhole. Your Martin dealer can advise you about sound reinforcement options for your guitar. Take the advantage of having the best made transducers paired with the best made acoustic guitars. You’re guaranteed to sound the best!