GUITARTRACKS
Your Acoustic, Amplified
I have been gigging out more recently, and
I found myself in need of decent acoustic
amplification. The good news is that there are
more options available to acoustic guitarists
than in the past – we no longer have to buy
an acoustic/electric and hope it sounds good
with our Twin. We can build an entire signal
chain that meets the specific needs of acoustic guitars – starting with the pickups.
deal since then and several manufacturers,
including Dean Markley and Seymour Duncan,
have humbucking acoustic guitar designs. The
magnetic designs are easy to mount (they
typically clip into the soundhole) and take
into account body resonances, so gain before
feedback is very good.
been voiced to give a natural-sounding result.
K&K Sound, Trance Audio and other manufacturers offer transducer systems that can be
installed aftermarket – there are even versions
that work with nylon-string instruments.
Because of the resonant nature of the acous-
tic guitar, designing a pickup that accurately
recreates the sound of the instrument and
is resistant to feedback has been a
challenge for manufacturers. The
available pickup products fall into
four major categories: piezo (under-
saddle), magnetic, mini mic and body
sensor. A fifth option is to combine
two or more of these.
Internal Mics
Mini microphone technology now allows us to
mount an acoustic guitar-specific mic inside
our guitars to pick up the natural body resonance and character. Although very natural
Hybrid
A solution that’s becoming more and more
common is the hybrid approach, which com-
bines two or more of the above technolo-
gies. The designer can take the best part of
each approach to achieve natural-sounding
resonance and feel, while reducing feedback
problems. Manufacturers including K&K
Sound and Highlander offer hybrid sys-
tems that combine an internal mic with
an undersaddle pickup or an undersad-
dle pickup with a magnetic pickup.
Piezos
Piezo (short for “piezoelectric”)
pickups fit under the bridge saddle.
They have a wide, even frequency
response, are rugged and low-noise,
and don’t exhibit feedback prob-
lems at loud stage volumes. They
are inexpensive and can be added
“aftermarket” to guitars that come
without pickups. There are two types:
the traditional pressure and vibration-
sensitive variety, and, for those using
really light strings or low tunings, vibra-
tion-only sensing piezos.
The Seymour Duncan SA- 3 “Woody” magnetic sound-
hole pickup is available in either single-coil or hum-
bucking versions
sounding when set up correctly, these solutions often have feedback problems at high
stage volumes. As a result, they are often
paired with one of the other solutions discussed here – more on hybrid approaches
below. Of course, not just any mic will work –
specialized mics that mount inside the guitar,
such as the GHS MiniFlex Mics, the Joe Mills
internal-mount electret condenser mics (
unfortunately not in production as of this writing)
or the Highlander Internal Mic, are voiced to
provide natural sound quality.
Electronics
Piezos, in particular, require a fair
amount of preamp gain and EQ to get
rid of that spanky, quacky, under-the-
string sound – this may mean onboard
electronics or an external preamp/EQ
unit. Other pickup and mic technolo-
gies also benefit from basic built-in EQ
controls that allow the player to tweak
the guitar tone. You can take that to
another level using an outboard EQ for
even greater control, paying particular
attention to the midrange. Having a
sweeping mid control is a plus for get-
ting rid of that annoying nasal quality.
Fishman recently introduced a twist in this
area by adding modeling to piezos with their
Aura Acoustic Imaging products. With this
technology, they have physically modeled
the sounds of professionally mic’d acoustic
guitars – they can even model your specific
guitar. By applying these models to the piezo
pickup output, the body resonance and “air”
that the undersaddle piezo lacks is added
back in. They’re incredibly convincing; you
won’t believe you’re hearing your old undersaddle pickup.
Try a number of guitars with various pickup
and mic’ing systems to hear the differences
and to find what you like. In many cases,
these technologies can be retrofitted to your
existing guitar. Whatever method you choose,
installing the right pickup system in your guitar is essential for great live acoustic guitar
sounds without fear of howling feedback. And
don’t forget that an electro/acoustic guitar
is useful in the studio as well, as a blended
texture with mics or as a fresh tonal voice all
its own.
Magnetic Pickups
Magnetic pickups have been used to amplify
acoustics for years – they’re quite similar
to the pickups found in your electric guitar.
Remember those old Harmonies or Gibson
J-160s? Those have a P- 90 variant in them. Of
course, the technology has improved a great
60 PREMIER GUI TAR S JEUPNTEEM2B0E0R8 2008
Sensors
Body sensor pickup technologies like the
Taylor Expression system can sound truly
amazing, although in my experience they are
not as feedback resistant as piezo or magnetic
pickups. These systems use sensors to detect
vibration in different areas of the instrument
and then blend them in a preamp that has
David Hess
David Hess grew up in a guitar shop. He has been
involved in selling, repairing, and collecting guitars
and amps since he was 14 years old. For the past ten
years he has been a Sales Engineer at Sweetwater.
Reach him at (800) 222-4700 ext. 1398 or
david_hess@sweetwater.com.
