| Articles:
Electric Guitar Piezo Pickup Saddles & Bridges: Advanced Effects |
| My name is Alan, and I'm an electric guitar
piezo bridge addict - and happy about it. I started out with the original hardtail
Fishman Powerbridge (the first model available locally), and have never looked back since.
Three out of my four 6-string electric guitars now have piezo equipped bridges, and they
have become an integral part of my sound and playing. In this series of articles, I'm going to take a look at all things piezo:
what they are, how they work, what you can do with them, amplification and FX, some ideas
and sound samples and some pretty advanced applications. |
A bridge fitted with piezo saddles. |
Advanced Effects
The basic sounds of a piezo equipped guitar are fairly obvious: magnetics alone,
piezos alone or both sounds blended together. I won't cover the magnetic sounds here, as
you're probably already well aware of the range of sounds you can get from your instrument
(or should be!). I've already covered the basic effects processing needs of piezos, but
now I'm going to look at a few other exciting things you can do with effects.
Sonic differences between piezo and magnetic
pickups
Understanding the difference between the two types of pickup is important
to understand as it allows you to use the effects to their best... err... effect. |
- Tone
Conventional magnetic guitar pickups and amplification is limited in
frequency range, usually tapering off in the 4KHz region. Piezo pickups are pretty good
across the same range and higher - up to about 12KHz.
- Attack
Piezos also have a snappier and accentuated attack - which makes the sound
clearer and punchier and make plectrum noise stand out more. The attack from magnetics is
looser - which gives a fuller, rounder tone - especially in the low end.
- Dynamics
The two systems have completely different dynamics (as discussed in the compression
section of Basic FX). If you set the volume of
the two sounds the same while playing at normal levels, playing softer will make the
magnetic pickups stand out more, but playing harder will make the piezos jump out louder
than the magnetics.
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Blending sounds
Once you have started using the magnetic and piezo sounds together, it becomes
addictive. You start out using one or the other sound, but when you realize what you can
get with both sounds together (distorted electric guitar sounds with clean
"acoustic" sounds overlaid, for instance), and you start using different
combined sounds all the time. To blend the two sounds effectively, look what they do
naturally and use it to your advantage.
So, using what we now know about the differences in the two
types of pickup, we can use them to complement each other's sound:
- Use playing dynamics to make the balance change
between the two types of pickups
As mentioned already (repeatedly), piezos and magnetics have different
dynamics. If you set the volumes of the two to similar levels when playing with normal
hardness, the magnetics will dominate if you play softer than that and the piezos will
jump out when you play harder.
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- Need to get an electric guitar sound to cut through
the mix better?
Take the magnetic sound as your basic sound and add in just a little piezo
sound to the mix. Equalise the lower and midrange frequencies out of the piezo. This will
increase the attack of your overall sound without changing the overall tone or volume too
much. Don't worry if the piezo sounds lame by itself - it's a tone made
specifically for blending and you wouldn't normally use it by itself.
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| Sound
Clip |
brightness.mp3
Piezo sound added half way through
the clip to brighten the magnetic sound. |
|
- If you want to get a fuller acoustic sound
Blend in a little of the lower end of your magnetic pickups (particularly
your neck pickup, which produces more bass) to flesh out and thicken the low end. Also
experiment with adding one or two narrow frequency bands of magnetic sound in the midrange
to simulate an acoustic's soundbox resonance.
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Making them stand apart
In Basic FX we looked at panning as a
way to make the two sounds stand out from each other, but we can also use EQ and reverb to
make them distinctly different.
EQ - Looking at the tonal
differences between the two types of pickup, you can see where they stand apart naturally
(the high and, to a lesser degree, the low frequencies), and where they are similar (the
midrange). So it's easy to EQ them to accentuate this - boost the highs of the piezo
slightly and cut them on the magnetics, as well as boosting the lows of the magnetics and
cutting them on the piezo. In the midrange, where they are both strong, cut lower mids on
either with a corresponding boost on the other and do the reverse on the upper mids. An
alternate option is to boost all the mids on the electric and cut the bass and high
frequencies, while doing the reverse on the piezos. Experiment, experiment, experiment.
Reverb - By using different reverb
"spaces" with different tonalities for the different pickup sounds, you can also
help make them stand apart. Just be careful not to use too much as this will make them
both dissapear in your band mix.
Using one sound to "pad" the other
Reverb can fill a lot of sonic space with it's "wash" of sound. The only
problem is this has a tendency to make things sound further back in any mix and lack
distinctness. We can use this to our advantage though. Using a lot of reverb on one sound
so that it fills space, we can use the second pickup's sound dry, with no reverb, and it
will cut through the wash. |
| Sound
Clip |
pad.mp3
The pad starts half way through. |
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There are other tricks you can do also use with this: If you
pitch shift the pad sound before you apply reverb, you can make bright pads (octave up),
dark pads, (octave down), or even dissonant or harmonic pads with other intervals.
Another thing to try is using a "slow gear" type
effect that fades in each note to remove the attack from the pad and create a swelling pad
- you can even do this manually with the volume control or a volume pedal.
Also try various stereo modulation effects after the reverb
(such as phasing, autopanning, auto wah, etc.), or even distortion for really thick pads.
Fun, fun, fun.
Thickening up the piezo sound
Short delays, "ambience" reverbs and chorus all help thicken up the piezo
sound. Something that might not be so obvious is using a pitch shifter to add in a tiny
amount of octave up or octave down signal. Too much and the sound can become quite
artificial, but experiment and you'll find the right amount for you. If you add in enough
octave up signal, you get a pseudo 12-string sound.
Adding acoustic body & tonality
Dedicated acoustic processors are relatively new on the market, but have added a
new wrinkle to piezo processing: acoustic guitar modelling. They let an acoustic guitarist
using piezo pickups model the relatively neutral pickup sound into simulations of a
variety of acoustic guitars, similar to the Line 6 Variax modelling guitars - but without
the need to use the Variax instruments themselves. Popular models include the Boss AD-8
and the Fishman Aura.
The Boss AD-8 features six different acoustic guitar
models. It also has a few basic FX such as reverb, 4-band EQ and Anti-Feedback, but lacks
the chorus that many acoustic guitarists find essential. The onboard tuner is nice, as are
the balanced XLR outputs. I have not tried one yet, but will get one from Boss in the near
future to review.
The Fishman Aura is an interesting concept, as it is
designed to make a piezo equipped acoustic sound like itself - but miced up with a good
microphone. While it has a variety of preset acoustic "Images", it is not really
designed to make one guitar sound like another, and as such is not suitable for electric
guitar piezo systems.
| Two guitarists? |
|
| This is one of my favorite tricks for one of
the two sounds. I use a long delay sync'ed to the tempo of the music (1/4 note value or
longer). Feedback/regeneration is set to zero, as is the direct signal. Essentially, this
means the signal is delayed by 200-500ms, so the piezo sound happens long after the
electric sound. Then I "play off" the delay and the result sounds like a really
tight, syncopated electric and acoustic guitar duo. |
|
| Dynamic effects |
|
| The difference in dynamics also means that any
effects on the piezo pickups also have different dynamics. This means if you have a dry
electric sound blended with piezos, and have reverb only on the piezos, the reverb will be
very soft when you play softly and increase in volume when you play harder. You can even
cut the direct sound of the piezos and have a reverb tail which is completely different to
the electric guitar sound - both in dynamics and tone. |
| Sound
Clip |
dynamics.mp3
The piezo is delayed, but the delay is only
obvious on the accented beats |
|
| Gates |
|
| This is another really fun thing to do and
builds on the dynamic difference of the piezos. Set up a gate on the piezo signal. Set the
threshold fairly high so that it only opens when you play quite hard. The piezos will be
turned off for soft to medium playing and when you play harder, the gate opens, letting
through the piezo signal. This also works really well if you have a fairly extreme effect
on the piezos, as it means that the effect is also gated and makes no sound until you play
harder. |
| Sound
Clip |
gated.mp3
The delay is completely silent during the
quieter sections |
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To sum up
The examples above are exactly that - examples. Use them as a jumping board to
branch out and create your own sounds. Use your imagination to come up with more and
different sounds - imagine it and then try and create it. You may find that even if you
don't find the exact sound you have in your head, you find other interesting noises along
the way and, as an added bonus, you learn to use your effects. Above all, remember that at
the end of the day, the sounds you use must compliment the music.
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