| Articles:
Electric Guitar Piezo Pickup Saddles & Bridges: Basic Effects Processing |
| 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.
|
Basic Effects Processing
If you want to keep your piezo equipped guitar sounding like
an acoustic guitar, piezos benefit from the same type of effects processing as that
instrument: compression, EQ, chorusing, delays and reverb. However, there is nothing to
say you can't experiment with other effects, phasing, pitch shifting, even guitar
amplifier sounds can work on occasion - as always, use your ears. Now let's take a look at
the commonly used effects and how they affect the sound.
Compression
Piezo pickups have completely different dynamics to magnetic pickups.
Electric guitar sounds are usually quite compressed thanks to the inherent compression of
electric guitar amplifiers and the louder or more distorted they are, the more compressed
the guitar sound becomes. Piezo pickup sound is a lot more dynamic, going both louder and
softer than the electric. So depending on how hard you play, the balance between magnetic
pickups and piezo pickups varies.
Personally I like the difference in dynamic response between
the two types of pickup, as it allows me to change the mix between the two depending on
how I play. However, there are occasions where you want the two to respond to your playing
in a similar fashion, both staying at the same volume. This is when it's time for
compression.
To do this, set the compressor with a 5:1 or greater ratio
and set the threshold fairly low to give it a slightly tighter, "squashed"
sound. The attack of piezos is fast, so set the attack quite fast with a slightly slower
decay. When you get the settings right, the acoustic and electric sounds will both be as
loud as each other, regardless of how hard or soft you play.
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Magnetic pickup
(top). Uncompressed piezos (bottom). The peaks are louder and the quieter parts are softer
than those of the magnetic pickup, .
Sound Sample comp1.mp3 |
Magnetic pickup
(top). Compressed piezos (bottom). The dynamics of the piezos are now similar to those of
the magnetic pickup.
Sound Sample: comp2.mp3 |
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| EQ |
|
| This is quite variable depending on the piezo
system and the amplification you are using. General EQ rules apply: it is always better to
reduce frequencies than boost and if you find you are boosting or cutting a frequency by
more than 6dB, something is wrong. Below are a
few key frequencies, but bear in mind these are general guidelines: use them as a starting
point depending on what works best for you. |
| EQ Sound Samples eq1.mp3
A Blended sound
eq2.mp3
Piezos EQ'd to fit "around" the magnetic sound. |
|
| Frequency |
Effect |
| 80Hz & down |
Reduce to remove "thump" and handling noise.
Shelving EQ |
| 100Hz |
Increase to add fullness. Reduce to remove boom and
increase clarity. Peak EQ with a Q of 1.0 |
| 200Hz |
Increase to add a "harder" fullness, reduce to
decrease muddiness. Peak EQ with a Q of 1.4 |
| 800Hz |
Reduce to remove "cheap" sound. Peak EQ with
a Q of 1.0 |
| 1.5KHz |
Reduce to remove dullness. Peak EQ with a Q of 1.0 |
| 2KHz |
Reduce to cut the spike from steel saddles and make the
sound more natural |
| 3KHz |
Increase for more attack. Decrease for removing the
"dreaded piezo quack". Peak EQ with a Q of 1.4 |
| 5KHz |
Increase to add attack and brightness. Peak EQ with a Q
of 1.4. Reduce to soften "thin" guitar. Peak EQ with a Q of 1.0 |
| 7KHz |
Increase to add "sharpness". Peak EQ with a Q of
1.0 to 1.4 |
| 10KHz |
Increase for fine detail or "air". Peak EQ with a
Q of 1.0 |
| 15KHz & up |
Reduce to cut noise. Shelving EQ. |
Reverb
A little reverb is always welcome, filling out the sound and smoothing an
edgy sound. The general rules of reverb apply - the less reverb you have, the more up
front a sound will be, while a lot of effect will make the sound appear further back in
the mix. Bright halls or plate reverbs are well suited to the high end detail of the piezo
sound. Darker reverbs can help tame an edgy sound without losing detail. Shorter reverbs
(smaller rooms) will often help keep the punch of the sound. Ambience patches will thicken
up the sound.
Chorus
You might like chorus to sweeten and thicken up the piezo sound. Used stereo, you
can split the piezo sound left and right and keep the magnetic pickups in the centre. Use
chorus conservatively, as too much effect can make the guitar sound out of tune and also
make it disappear in a mix.
Delay
You can also make the piezos sound bigger by using a short delay between 10 and 20
ms, panning the original to one side and the delayed signal to the other side. Keep the
feedback/regeneration all the way down. Shorter delays than 10ms will introduce a phased
sound, while longer than 20ms they will start sounding like distinct echoes. Long delays
can be used as long as they are in sync with the tempo of the piece of music. If your
delay has a detune or modulation function, you can also use a touch of this to further
differentiate the two and make the combined sound even bigger.Panning
Panning the two sounds to different positions in the stereo spectrum is a good way
to help the two sounds unmask (separate). Always check the sound in mono, to make sure
there is no nasty phase cancellation causing drastic tone changes. Onstage, either use
mono or keep the stereo field very narrow to ensure the balance between the two sounds
does not change too much as a listener moves around the room. |
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