Full Bucket's
Frequency Shifter
VST™2.4 Effect
Version 1.0
© 2012 by Björn Arlt @ Full Bucket Music
http://www.fullbucket.de/music
VST is a trademark of Steinberg Media Technologies GmbH
Frequency Shifter Manual Page 2
Introduction
The Frequency Shifter is a VST™2.4 software effect for Microsoft® Windows® written in
native C++ code. The main features are:
● Frequency shifting up to ±5000 Hz
● Optional LFO with five waveforms
● Four frequency ranges, three mix modes
● Linked or individual control for both stereo channels
● Plug-in comes in 32 bit and 64 bit versions
● Fully compatible with SM Pro Audio's V-Machine™
The Frequency Shifter shifts the spectrum of the input signal up or down along the
frequency axis. This effect is also know as “Bode Frequency Shifting” or “Single
Sideband Modulation” ‒ imho one of the most underrated and ignored effects ever.
Do not confuse the Frequency Shifter with a pitch shifter! A pitch shifter multiplies all
frequencies of the input signal by a constant factor while a frequency shifter adds (or
subtracts) a constant amount of Hertz to (or from) those frequencies. Thus, the
harmonic structure of the input signal will not be preserved in the modulated signal,
resulting in a raw, inharmonic, metallic, you-name-it sound the more you apply the
effect. Even more, if you mix a slightly shifted signal with the original input signal you
will get some uncommon phasing sound.
Architecture
The input signal is fed into a Hilbert Transform, an all-pass network that outputs two
signals (the “real” and the “imaginary” signal) which are mutually phase shifted by
90°. This pair of signals represents kind of a “complex” version of the input signal
(without negative frequencies).
The signal pair is then modulated by a complex sinusoid (a cosine and a sine, i.e.
again a signal pair mutually phase shifted by 90°) resulting in a frequency shifted
version of the input. The amount of shifting may be controlled by am optional LFO.
Finally, the effect signal can be mixed with the original input or one of the outputs of
the Hilbert Transform (the “real” or the “imaginary” signal).
Note that shifting the signal spectrum “below” zero Hertz will result in negative
frequencies that are clearly audible, meaning that at some point frequencies you're
shifting “down” will reappear as frequencies that are rising “up”! This is not a bug of
the Frequency Shifter but a fact of Digital Signal Processing mathematics. For more
information see for example “The Scientist and Engineer's Guide to Digital Signal
Processing” by Steven W. Smith, Ph.D. (a free PDF version of this great book is
available at www.dspguide.com).
Frequency Shifter Manual Page 3
Parameters
parameter description
Frequency Range the range of the frequency shifting (±5Hz, ±50Hz, ±500Hz,
or ±5000Hz)
Min. Frequency L controls the minimum shift frequency for left channel; will
be inactive when LFO is off
Min. Frequency R controls the minimum shift frequency for right channel; will
be inactive when LFO is off
Max. Frequency L controls the maximum shift frequency for left channel
Max. Frequency R controls the maximum shift frequency for right channel
Mix L mix balance for left channel
Mix R mix balance for right channel
Mix Mode L selects the signal (Input, Real or Imaginary) to be mixed
with the effect signal (left channel)
Mix Mode R selects the signal (Input, Real or Imaginary) to be mixed
with the effect signal (right channel)
Volume L output volume for left channel
Volume R output volume for right channel
Link optionally links both left and right channel controls
LFO Wave selects the waveform of the LFO (triangle, rectangle, ramp
down/up, sample & hold) or deactivates the LFO
LFO Rate controls the rate of the LFO (0‒20Hz)
Frequency Shifter Manual Page 4
Frequently Asked Questions
How do I install the Frequency Shifter (32 bit version)?
Just copy the file freqshifter.dll from the ZIP archive you have downloaded to
your system's or favorite DAW's VST plug-in folder. Your DAW should automatically
register the plug-in the next time you start it.
How do I install the Frequency Shifter (64 bit version)?
Just copy the file freqshifter64.dll from the ZIP archive you have downloaded to
your system's or favorite DAW's VST plug-in folder. Your DAW should automatically
register the plug-in the next time you start it.
Note: You may have to remove any existing (32 bit) freqshifter.dll from your VST
plug-in folder or else your DAW may screw the versions up...
How do I install the Frequency Shifter on the V-Machine?
First of all: Make sure that you have installed the latest V-Machine firmware and VFX
software (available from www.smproaudio.com). The Frequency Shifter is known to
work with version 2.0.20101204. :-)
Second: I will not take any responsibility if the following install procedure does not
work for you, corrupts or damages your V-Machine, or bores you! :-P
Now to the point: Export the contents of the ZIP archive to a temporary folder on your
PC/Mac, run the VFX software, and import the freqshifter.dll 32 bit plug-in from
this folder; make sure to choose the “Don't use a Wizard file” option. The VFX
software will tell you that “there is no guarantee that it will run on a V-MACHINE
without a wizard's help”. That's OK, no magic here. ;-)
Finally, create a preset for your V-Machine that uses the Frequency Shifter.
What is the VST plug-in ID of the deputy?
The ID is F B F S .
What the heck is happening when I shift my signal down???
Weird stuff. Please re-read the last note in the Architecture section.
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