Waves Audio SoundShifter User Guide

Waves – SoundShifter

Software Audio Processor

User’s Guide

Waves SoundShifter software guide page 1 of 13

Chapter 1 – Introduction and Overview

The Waves SoundShifter is a high-quality Time Scaling
(compression/expansion) and Pitch Shifting audio processor. Different from
the well-known vari-speed and re-sampling techniques, SoundShifter is
special in that it can perform high-quality Time Compression/Expansion
without necessarily changing the pitch at all, or change the pitch of any audio
signal without changing its duration. You can say that the Sound Shifter
separates the speed and the pitch so that each can be manipulated
individually. There are two main controls – Time Ratio specifies the speed of
the output and the Pitch Ratio control specifies the change to the output pitch.
The SoundShifter offers a user interface that makes it easier to specify the
desired Source/Destination ratio by offering multiple value formats that cover
all of the time-related formats and pitch related units that are common in audio
editing and processing applications. When the Time and Pitch ratios are the
same, the SoundShifter will perform as a high quality vari-speed re-sampling
tool.

SoundShifter can shift, stretch and compress up to twice as fast, slow, high or
low. That’s a maximum ratio of 2 or 0.5 in any direction you choose. Special
attention was given to the accuracy of the process timing, which is critical in
many applications. We allowed as much resolution as the floating point
process allows us. There are very few processors that can do this and offer
similar quality to that of the SoundShifter. Through careful research we
constructed an intelligent algorithm that focuses on the areas where the
human ear is most sensitive. SoundShifter maintains high integrity by
preserving the groove and timing as well as attacks and transients.

This type of processing is not a purist process, but in modest ratios we claim
relative transparency. So if you need to shift just a bit, the results are very
clean, even on mixed music of any genre. The higher the ratio, the less
natural the sound will be, especially on the human voice and more complex
and full signals. The formants will shift with the pitch and the length of all the
elements will change considerably. Still, for scaling the sustain of an
instrument’s notes, adjusting a song to an advertising spot time and many
other creative applications, the SoundShifter is the right tool for the job.

The SoundShifter consists of 3 main components –

• Parametric SoundShifter – Designed to shift the speed and pitch
of a selection with a fixed ratio.

• SoundShifter Pitch – Parametric Pitch only, made for real-time
pitch processing of any given signal.

• Graphic SoundShifter – Allows changing the ratio through the
selection by drawing an automation graph.

The Parametric and Graphic SoundShifter are “Offline” processors because
they avoid the real-time processor’s artifacts of gaps in the audio or long
delays.

Waves SoundShifter software guide page 2 of 13

The SoundShifter pitch component is designed for real-time processing. It has
a fixed latency.

The real-time intelligent algorithm is very demanding on CPU consumption, so
you are limited in how many you can use on your mix. For the offline
processors this is not a problem, but when performing such processing on
96kHz material, the real-time preview operation is also limited. To properly
hear or preview the results it is best to apply the process to short segments
and, if satisfactory, run it over the whole selection.

Chapter 2 – Using the SoundShifter

THE PARAMETRIC SOUNDSHIFTER

The Parametric SoundShifter is divided into two main sections plus a global
setup section. It allows adjusting two main properties:

1. The Time Ratio, which sets the speed up to twice as fast or
down to half as fast.

2. The Pitch Ratio, which sets the Frequency ratio up to twice as
high or low, which is equivalent to one octave up or down.

For your convenience, this ratio can be specified in any time or speed unit that
is commonly used in audio editors. The Parametric SoundShifter represents
the ratio in Source and Destination columns where “Source” represents the
selection length and “Destination” represents the length of the processed
output. The pitch section allows specifying the ratio by musical interval in
semitones and cents or frequency difference in Hz.

In the middle of the Parametric SoundShifter user interface there’s a setup
section for setting some global SoundShifter options as follows:

SMPTE FORMAT - the SMPTE format (see SMPTE).

Waves SoundShifter software guide page 3 of 13

METER – The musical signature meter defines the number of beats within a
bar and the musical length of each beat. It is important for calculating an
accurate Bars & Beats time view.
MODE: Sync, Smooth, Transient and Punchy. Default: Transient.
This selects one of four algorithm optimization settings.

SYNC is the most timing sensitive optimization and is a good choice
when processing multiple tracks that are phase-related such as a
drumset micing array. In small ratios this mode does a great job. In
higher ratios, however, this mode will allow similar stretching to
transient and continuous components. This makes the sound more
smeared and less articulate.

MOOTH continues to use some more of the SoundShifter’s

S

sophistication and preserves better articulation. This optimization is
good for voice and wind instruments or mixed classical music.

T

RANSIENT goes another step into preserving better attacks for

transients but this requires a slight compromise on the timing of the
transients attack. Good mode for Piano, Guitar or other plucky
instruments.

PUNCHY is the super punch-preserving optimization. It is specially
made for Percussive sounds, and beat music.

LINK MODE: Unlinked, Time, Pitch, Strapped. Default: Unlinked.
In unlinked mode, the Time and Pitch controls are independent. When

selecting one of the other link modes, each section relies on the other.
Pitch Link Mode shifts the both the Pitch and the Time by the Pitch ratio, all

Time editing possibilities are void in this mode.
In Time mode the Pitch and the Time shift are adjusted by the Time Ratio, all

Pitch controls are disabled in this mode.
In Strap mode you can engage or break the link between the Pitch and the

Time at any moment preserving their current offset or performing high quality
resample when link from the start.

Waves SoundShifter software guide page 4 of 13