Ask any acoustic guitarist, and they'll tell you their biggest challenge: amplifying the dang thing in a live situation. The three perennial solutions all have serious drawbacks: soundhole pickups can have a nice warm and fuzzy tone, but they don't sound very much like an acoustic guitar; saddle-mounted piezo pickups sound scooped and plastic-like at best, brittle and offensively harsh at worst; and mic'ing an acoustic guitar-the best-sounding option-just isn't very practical since the instrument invariably moves around during live performance.
The folks at Taylor were all too aware of these pitfalls and decided to do something about it. They spent years researching and developing a whole new method of amplifying an acoustic guitar and dubbed it the Expression System. This system exploits the fact that an acoustic guitar radiates sound through the vibrations of its entire top, as well as neck. Taylor put a magnetic sensor underneath the spot where the guitar's neck meets the body, as well as two other sensors inside the guitar, attached to the underside of the guitar's top. My understanding is that these three sensors pick up the guitar's resonance-as opposed to only the strings' vibrations-in a sort of floating, three- dimensional way. Their signals are then combined through a Rupert Neve-designed preamp/DI circuit (powered by two AA batteries) and output as a fully-balanced line-level signal. The guitar comes with a TRS-to-XLR cable which can be plugged directly into a PA system or mixer-no need for a DI box. A standard guitar cable can be used in a pinch, but the advantages of the balanced, low-impedance output would not be available.
I recently had the opportunity to try a Taylor 514-CE, an upper-end model in the Taylor line which comes with the Expression System as a standard feature. This small-bodied, single-cutaway guitar is, typically for Taylor instruments, beautifully crafted and "ready to play" right out of the box. It was sent to me and arrived about 90% in tune, which strikes me as a testament to its integrity. When playing it unplugged, my initial thought was that the neck was a bit on the skinny side, yet quite comfortable. (In fairness, I should mention that I personally play more electric than acoustic these days, and that my neck taste can sometimes run to the "tree trunk" category.) I let a few guitarist friends try it out, and across the board they loved the feel and playability of it. The un-amplified sound was crisp and very well balanced. Each note was bell-like and distinct, yet chords melded together nicely. This being a small-bodied guitar, it was not surprising that the lower strings did not sound as "huge" as they might on a jumbo or dreadnaught body.
When it came time to try the Expression System, I booked a couple of low-key acoustic gigs at clubs I knew had decent PA's. The first gig was a solo acoustic one in which I played and sang strummy songs with very few single note passages. At soundcheck, I plugged the XLR end of the cord into the PA, turned the channel up to unity gain, and slowly turned up the volume. After a brief howl of feedback (er, my bad...) I got the hang of things and messed a bit with the three sleek knobs mounted on the upper bout of the guitar. They're unlabeled, but easy to figure out: volume, bass, and treble. They're all center- detented and very ergonomic; it's easy to twiddle them with just one finger or thumb, and they offer just enough resistance to avoid an overshoot. To my ears, the guitar sounded so natural with the knobs in the center position that I decided to leave them flat. I went ahead and played my set-it was a pleasure. The guitar felt and sounded great and bolstered my confidence. Afterwards, several friends remarked on the great sound of the guitar, saying it sounded like a mic'ed up acoustic, rather than a typical plugged-in one. The next gig was a few weeks later and was different in that my friend Aaron Tap joined me on electric. We played mostly instrumentals, and I found the tone knobs very helpful and necessary this time. Turning the bass knob up to about 3 o'clock gave my lead lines and partial chords more body and balanced out Aaron's stingy, reverby Telecaster. The Expression System seemed to have headroom galore; it didn't "seize up" the way piezo pickups do. Loud notes were loud and clear, quiet notes were quiet and clear. Again, a pleasure to play. The Taylor felt and sounded so natural, it relaxed me and made the gig really fun (which, as I recall, is kind of what we're all shooting for...).
Pluses: unprecedented natural sound quality for an amplified acoustic guitar; low-profile; easy-to-use; really, it's the best overall acoustic amplification system to date.
Minus: Expression System is currently only available on Taylor guitars. (Certainly nothing against Taylor guitars. It would just be a nice option to be able to install the Expression System in an older, favorite guitar of a different make. Perhaps some time down the road.)
Addendum: Taylor, with the able help of Rupert Neve, designed a preamp/DI/equalizer, the K4, specifically voiced for use with any amplified acoustic guitar, but clearly marketed as a companion piece to the Expression System. This is an elegant standalone device with a sleek, postmodern metal body and a classy, dark wood panel on top. It can be rackmounted on a universal rack tray. The K4 is full-featured for sure, with a full range of inputs, outputs, fully-balanced effects loop, phase flips, a headphone jack, a handy tuner output, and a main output mute button. Powered by an AC adaptor or two C batteries (the battery option is intended as sort of an "emergency" route; in case you forget your wall wart, the batteries can get you through a gig), the K4's bragging point is its three-band (Neve- designed) equalizer. The high and low bands are centered around 100 Hz and 10 kHz, while the midrange is fully parametric, ranging from 80 Hz to 8 kHz, with a bandwidth ("Q") control. The EQ section is super-sweet and, in the tradition of Neve, hard to make sound bad unless used to an extreme. But I have to say I found the K4 more helpful when used with non-Expression System- equipped acoustic guitars, electric guitars and basses, and even microphones (makes a nice mic preamp/EQ). The thing is, the Expression System sounds so good on its own, I didn't find that the K4 was needed with the Taylor 514-CE guitar. That's just me, though; I'm sure a guitarist who specializes in very subtle, intricate finger- picking would find the K4 to be a godsend. (Expression System guitars $1998-$11,798 MSRP depending on model, K4 Equalizer $899; www.taylorguitars.com)