Octave dividers aren’t just for guitar
players: They also rock for bass,
whether you’re getting mega-low
sounds from the lower strings, or
playing high up on the neck for very
cool 8-string bass effects. It’s easy to
do octave division with amp sims
and DAWs, but there are some definite
tricks involved.
Split Your Signal
As when adding many other types of
effects on bass, it’s best to create a
second track in parallel with the
main bass sound, and dedicate the
second track to the octave divider.
This lets you mix in the precise
amount of octave sound, but more
importantly, you may need to condition
the bass signal to optimize it for
octave division.
Choose Your Divider
Most amp sims include octave
dividers. I’ve successfully used octave
dividers on bass with IK Multimedia
AmpliTube 2, Waves GTR Solo (Figure
1) and GTR3, Native Instruments Guitar
Rig 3 (Figure 2), Line 6 POD Farm,
and Peavey ReValver Mk III. There’s
not a lot of difference among these
particular effects; they all do the job.
You can also use the other available
modules to condition the bass signal.
Pre-Octave Processing
Two main problems can interfere with
proper triggering: an inconsistent
input signal level, and triggering on a
harmonic rather than the fundamental
(which causes an “octavehopping”
effect, where the signal
jumps back and forth between the
fundamental and octave).
A compressor can solve the consistency
problem. Set it for a moderate
amount of compression (e.g., 4:1 ratio,
with a fairly high threshold). Make sure
the compressed sound doesn’t have a
“pop” at the beginning, and the sustain
is smooth. Then if needed, patch
in an EQ to take off some of the
highs—the object is to emphasize
the fundamental. This may require
compromise; too much filtering will
reduce the level from the higher
strings to where they might not be
able to trigger the octave divider
(as well as change the tone),
whereas not filtering enough may
cause octave-hopping on the
lower strings.
What works best for me is cutting
highs and boosting the low bass a
bit. If the EQ curve isn’t sharp
enough, you may get better results
by patching two EQs in series. I’ve
also found that with Guitar Rig 3,
using the Pro Filter module with
mode set to LPF (lowpass) and slope
to 100% four-pole provides outstanding
conditioning, especially when
preceded by the Tube Compressor.
The Final Touch
Playing technique also matters.
Popping and snapping might confuse
the octave divider, as can the
transients that occur from playing
with a pick. Playing with your fingers
or thumb gives the best
results, but don’t be afraid to experiment;
for example, if you do “snap”
the string, the sound might mask
the divided sound anyway, so it
won’t matter. Also, remember that
octave dividers are monophonic, so
make sure only one string vibrates
at a time.
Once you have your signal chain
tweaked, adjust the parallel, octavedivided
signal for the right balance
with the main bass signal. You’ll
probably find yourself playing an
octave higher than normal, because
the octave divider will supply the
low fundamental. But octave division
is also a great way to make
those low strings create seismic-type
lows that throb in a way you can’t
get with any other technique.