13 Apr Subharmonic OSC Tutorial
Did your ever wonder where those enormous rumbles come from
whenever spaceships enter our solar system?
The sub basses in movies are often that low and loud that you can really
feel them. It is an element of excitement powerful enough to make the public jump out of their seat. This effect is often accomplished by using a Subharmonic
Oscillator.
What is it?
A subharmonic oscillator, also called subharmonic synthesizer, is similar to an octaver, but other than the one for your guitar, this
one was built to shake the earth. Because an octaver is usually just a type of
pitch shifter, the lower frequencies will begin to get messy when
things get
really deep.
To get nicely pronounced sounds you need a clean waveshape,
like a sine. Hence, a subharmonic oscillator adds sine waves to the input signal. These sine waves are subharmonic frequencies, which means they are lower than the fundamental frequency of the input signal in a ratio of 1 / x. Let’s say your input signal has a fundamental frequency of 440 Hz, then sub-harmonics include 220 Hz (1/2), 110 Hz (1/4), and so on. So to summarise, one could say that a subharmonic oscillator adds lower frequencies that are in tune with the input signal.
This is how a nice, round and deep bass is added to sounds that don’t naturally obtain much presence in the sub range.
Audio professionals use it to put bass in all
sorts of sounds. Big male voices, knife stabs, bullet impacts – anything that requires that cinematic impact.
Where to get it?
Of course there are various kind of hardware subharmonic synthesizers/oscillators, but these can be expensive. But with a bit of searching on the internet, one can find some
sofware equivalents.
Most of these also come with a pricetag, but there is also a free one
that does the job, which is the Edge, available for download at
codeaudio.com
And look what it does to our sinesweep:
you have to absolutely watch your precious speakers with this.
We can clearly see there is another sinewave joining in an
octave lower, a very strong (standing) wave.
You can even set the Edge to go as low as 2 octaves.
Now how to get that sub growling.
This will be a send effect, so you can
dial in some extra balls when things get heavy.
First we have to control what is going in the Edge. What you probably
want is that it only reacts to the strongest and loudest part of your
sounds. It does not have a gate built in so it will react to every sound.
It has a built in filter but it is important to know exactly what gets
through, so better use a reliable filter.
To get more control we first insert a resonant filter. With the filter
frequency and resonance you can pinpoint the area that you’d
like to
enhance.
After that a compressor-gate comes in to get the volume under
control. Use long attack and release settings because subbasses are
very sensitive to sudden changes in amplitude causing clicks and pops.
Now turn down the volume of your system by 50% because here
comes the
Fatass Edge, fiddle around with it until you get the feeling you can
control the amount and position of the signal.
It is immediately clear that certain evil powers woke up in
your
speaker. To get a hold of all that rumble we insert a limiter directly
behind the Edge. We go for loudness here. Just make sure it
doenst go
past say -6dB to leave some headroom for other sounds.
After that we insert an EQ with visual feedback so you can
hear and
see what to tweak. Cut a little in the area where the original bass is
still active and maybe boost the sweetest spot a little.
And after that we add just a little reverb to blend everything
together.
Examples we made:
original sound:
with subharmonic oscillator:
original sound:
with subharmonic oscillator:
Resources:
We dont recommend any particular 3rd party software and the plugins used
in
this tutorial are just preferred tools of the writer(s) of this article. We do
however post links to freeware, to ensure you have all the means to
follow this tutorial correctly.
  WIN:Pushtec 5+1A – is a 6-band mid-range and program EQ. A Winamp plugin version is also included. The Classic Master Limiter – VST plugin is specially designed to boost the overall level of your final mixes, but can also be used on very dynamic instruments. Classic Reverb is a nice and smooth reverb that does a good job on almost any instrument.   MACRogue Amoeba Mastering Plugin – not tested by yours truly, hence I dont work with mac, but seems to be one of the view free mastering plugins for mac out there! Slim Slow Slider: Linear Phase Graphical Equalizer 2.1 not tested by yours truly, hence I dont work with mac, but seems to be one of the view free mastering plugins for mac out there! |
Now go on and experiment with this to give your effects and beats that
extra professional sound quality.