Antares AutoTune 3 user manual

							5
If, for some reason, you do not have access to the web but do have email,
copy and paste your Challenge string and Registration Code into an email
along with your name and the product name (e.g., Auto-Tune 3 for MAS),
and send it to:
[email protected].
You will receive your Response by return email, typically within one
working day (unless you have registered on a weekend, in which case you
should receive it the following Tuesday).
If you do not have access to the web or email, fax your Challenge string
along with your Registration Code to us at 831.461.7801. Be sure to
include your fax number. We will fax the Response string back to you at
that number.
Technical Support
In the unlikely event that you experience a problem using Auto-Tune 3, try
the following:
1. Make another quick scan through this manual. Who knows? You may
have stumbled onto some feature that you didn’t notice the first time
through.
2. Check our web page for tips, techniques, or any late-breaking informa-
tion:
http://www.antarestech.com
3. Call your local Antares dealer.
4. Email our tech support department by pointing your web browser to:
http://www.antarestech.com/support/etech.shtml
and filling in the form there.
5. Call us at (831) 461-7814 Monday through Friday between 9am and
5pm USA Pacific Standard Time.
For options 3, 4, or 5, please be prepared to provide the Registration Code
of your copy of Auto-Tune 3.
01-39 AT3 man layout RGB03/05/2001, 1:30 pm 5 
						

							6
Chapter 2: Introducing Auto-Tune 3
Some background
In 1997, Antares Audio Technologies first introduced the ground-breaking
Auto-Tune Pitch Correcting Plug-In. Auto-Tune was a tool that actually
corrected the pitch of vocals and other solo instruments, in real time,
without distortion or artifacts, while preserving all of the expressive
nuance of the original performance. Recording Magazine called Auto-
Tune a “holy grail of recording.” And went on to say, “Bottom line, Auto-
Tune is amazing... Everyone with a Mac should have this program.” (In
fact, we know of quite a few people back then who bought kilo-buck
ProTools™ systems just to be able to run Auto-Tune. )
In the intervening years, Auto-Tune has become available for most every
major plug-in format and has established itself as the worldwide standard
in professional pitch correction. Today, it’s used daily by thousands of
audio professionals to save studio and editing time, ease the frustration of
endless retakes, save that otherwise once-in-a-lifetime performance, or
even to create unique special effects.
Now, never content to leave a good thing alone, Antares has created
Auto-Tune 3. Preserving the great sound quality, transparent processing,
and ease of use of Auto-Tune, Auto-Tune 3 adds significant new features
as well as a spiffy new user interface.
So what exactly is Auto-Tune 3?
Auto-Tune 3 is a precision tool for correcting intonation errors or cre-
atively modifying the intonation of a performance. Auto-Tune 3 employs
state-of-the-art digital signal processing algorithms (many, interestingly
enough, drawn from the geophysical industry) to continuously detect the
pitch of a periodic input signal (typically a solo voice or instrument) and
instantly and seamlessly change it to a desired pitch (defined by any of a
number of user-programmable scales or through the use of graphical
editing tools.).
01-39 AT3 man layout RGB03/05/2001, 1:30 pm 6 
						

							7
To take maximum advantage of the power of Auto-Tune 3, you should
have a basic understanding of pitch and how Auto-Tune 3 functions to
correct pitch errors. This chapter presents basic terminology and intro-
duces Auto-Tune 3’s operating paradigm, giving you information you need
to use it effectively.
A little bit about pitch
Pitch is typically associated with our perception of the “highness” or
“lowness” of a particular sound. Our perception of pitch ranges from the
very general (the high pitch of hissing steam, the low pitch of the rumble
of an earthquake) to the very specific (the exact pitch of a solo singer or
violinist). There is, of course, a wide range of variation in the middle. A
symphony orchestra playing a scale in unison, for example, results in an
extremely complex waveform, yet you are still able to easily sense the
pitch.
The vocalists and the solo instruments that Auto-Tune 3 is designed to
process have a very clearly defined quality of pitch. The sound-generating
mechanism of these sources is a vibrating element (vocal chords, a string,
an air column, etc.). The sound that is thus generated can be graphically
represented as a waveform (a graph of the sound’s pressure over time)
that is periodic. This means that each cycle of waveform repeats itself
fairly exactly, as in the periodic waveform shown in the diagram below:
Because of its periodic nature, this sound’s pitch can be easily identified
and processed by Auto-Tune 3.
Other sounds are more complex. This waveform:
is of a violin section playing a single note in unison. Our ears still sense a
specific pitch, but the waveform does not repeat itself. This waveform is a
summation of a number of individually periodic violins. The summation is
non-periodic because the individual violins are slightly out of tune with
respect to one another. Because of this lack of periodicity, Auto-Tune 3
would not be able to process this sound.
01-39 AT3 man layout RGB03/05/2001, 1:30 pm 7 
						

							8
Some pitch terminology
The pitch of a periodic waveform is defined as the number of times the
periodic element repeats in one second. This is measured in Hertz (abbre-
viated Hz.). For example, the pitch of A3 (the A above middle C on a
piano) is traditionally 440Hz (although that standard varies by a few Hz. in
various parts of the world).
Pitches are often described relative to one another as intervals, or ratios of
frequency. For example, two pitches are said to be one octave apart if
their frequencies differ by a factor of two. Pitch ratios are measured in
units called cents. There are 1200 cents per octave. For example, two tones
that are 2400 cents apart are two octaves apart. The traditional twelve-
tone Equal Tempered Scale that is used (or rather approximated) in 99.9%
of all Western tonal music consists of tones that are, by definition, 100
cents apart. This interval of 100 cents is called a semitone.
The twelve equally-spaced tones of the Equal Tempered Scale happen to
contain a number of intervals that approximate integer ratios in pitch. The
following table shows these approximations:
INTERVAL CENTS NEARBY RATIO INRATIO CENTS
minor second 100 16/15 111.75
major second 200 9/8 203.91
minor third 300 6/5 315.64
major third 400 5/4 386.31
perfect fourth 500 4/3 498.04
tritone 600
perfect fifth 700 3/2 701.65
minor sixth 800 8/5 813.69
major sixth 900 5/3 884.36
minor seventh 1000 16/9 996.09
major seventh 1100 15/8 1088.27
octave 1200 2 1200.00
01-39 AT3 man layout RGB03/05/2001, 1:30 pm 8 
						

							9
As you can see, the intervals in the Equal Tempered Scale are NOT equal to
the harmonious integer ratios. Rather, the Equal Tempered Scale is a
compromise. It became widely used because once a harpsichord or piano is
tuned to that scale, any composition in any key could be played and no
one chord would sound better or worse than that same chord in another
key.
How Auto-Tune 3 detects pitch
In order for Auto-Tune 3 to automatically correct pitch, it must first detect
the pitch of the input sound. Calculating the pitch of a periodic waveform
is a straighforward process. Simply measure the time between repetitions
of the waveform. Divide this time into one, and you have the frequency in
Hertz. Auto-Tune 3 does exactly this: It looks for a periodically repeating
waveform and calculates the time interval between repetitions.
The pitch detection algorithm in Auto-Tune 3 is virtually instantaneous. It
can recognize the repetition in a periodic sound within a few cycles. This
usually occurs before the sound has sufficient amplitude to be heard. Used
in combination with a slight processing delay (typically about 1 to 10
milliseconds), the output pitch can be detected and corrected without
artifacts in a seamless and continuous fashion. (Although it must be kept
in mind that some plug-in protocols introduce a certain amount of inher-
ent and unpredictable delay that depends largely on what else your CPU is
doing at the time.)
Auto-Tune 3 was designed to detect and correct pitches up to the pitch C6.
(If the input pitch is higher than C6, Auto-Tune 3 will occasionally inter-
pret the pitch an octave lower. This is because it interprets a two cycle
repetition as a one cycle repetition.) On the low end, Auto-Tune 3 will
detect pitches as low as 25Hz (when the Bass Instrument Input Type is
selected). This range of pitches allows intonation correction to be per-
formed on virtually all vocals and instruments.
Of course, Auto-Tune 3 will not detect pitch when the input waveform is
not periodic. As demonstrated above, Auto-Tune 3 will fail to tune up
even a unison violin section. But this can also occasionally be a problem
with solo voice and solo instruments as well. Consider, for example, an
exceptionally breathy voice, or a voice recorded in an unavoidably noisy
environment. The added signal is non-periodic, and Auto-Tune 3 will have
difficulty determining the pitch of the composite (voice + noise) sound.
Luckily, there is a control (the Tracking control, discussed in Chapter 3)
that will let Auto-Tune 3 be a bit more casual about what it considers
“periodic.” Experimenting with this setting will often allow Auto-Tune 3
to track even noisy signals.
01-39 AT3 man layout RGB03/05/2001, 1:30 pm 9 
						

							10
How Auto-Tune 3 corrects pitch
Auto-Tune 3 provides two separate and distinct ways to approach pitch
correction: Automatic Mode and Graphical Mode. The basic functionality
of each is described below.
Automatic Mode
Auto-Tune 3’s Automatic Mode works by continuously tracking the pitch
of an input sound and comparing it to a user-defined scale. The scale tone
closest to the input is continuously identified. If the input pitch exactly
matches the scale tone, no correction is applied. If the input pitch varies
from the desired scale tone, an output pitch is generated which is closer to
the scale tone than the input pitch. (The exact amount of correction is
controlled by the Retune Speed parameter, described below and in Chap-
ter 3.)
01-39 AT3 man layout RGB03/05/2001, 1:30 pm 10 
						

							11
Scales
The heart of Automatic Mode pitch correction is the Scale. Auto-Tune 3
lets you choose from major, minor, chromatic or 26 historical, ethnic and
microtonal scales. Individual scale notes can be bypassed, resulting in no
pitch correction when the input is near those notes. Individual scale notes
can also be removed, allowing a wider range of pitch correction for
neighboring pitches. The scale can be de-tuned, allowing pitch correction
to any pitch center.
For added flexibility, you can also select the target pitches in real time via
MIDI from a MIDI keyboard or a pre-recorded sequencer track.
Retune Speed
Auto-Tune 3 also gives you control over how rapidly, in time, the pitch
adjustment is made toward the scale tone. This is set with the Retune
Speed control (see Chapter 3 for more details).
•Fast Speed settings are appropriate for short duration notes and for
mechanical instruments, like an oboe or clarinet, whose pitch typically
changes almost instantly. A fast enough setting will also minimize or
completely remove a vibrato, as well as produce the infamous “Cher
effect.”
•Slow Speed settings, on the other hand, are appropriate for longer
notes where you want expressive pitch gestures (like vibrato) to come
through at the output and for vocal and instrumental styles that are
typified by gradual slides (portamento) between pitches. An appropri-
ately selected slow setting can leave expressive gestures intact while
moving the average pitch to the correct tonal center.
Vibrato
Auto-Tune 3 can also apply a vibrato to the input sound. You can program
the vibrato depth, vibrato rate and the onset delay of the vibrato. You can
also choose the shape of the pitch variation in the vibrato (sine, square or
sawtooth). By combining a fast Retune Speed setting with Auto-Tune 3’s
Vibrato settings, you can even remove a performer’s own vibrato and
replace it with Auto-Tune 3’s programmed vibrato, all in real time. Also,
unusual combinations of Vibrato Waveform, Rate and Depth settings can
be used for some interesting special effects.
01-39 AT3 man layout RGB03/05/2001, 1:30 pm 11 
						

							12
An Example of Automatic Mode Correction
As an example, consider this before-and-after graphic representation of
the pitch of a vocal phrase that contains both vibrato and expressive
gestures.
10.0 10.5 11.0 D3
B2 C

3
ORIGINAL
PERFORMANCE CORRECTED BY 
AUTO-TUNE 3
In the original performance, we can see that although the final note
should be centered around D, the vocalist allowed the tail of the note to
fall nearly three semitones flat. The “after” plot is the result of passing
this phrase through Auto-Tune 3’s Automatic Mode programmed to a D
Major Scale (with C # and B set to ”Remove”) and a Retune Speed setting
of 25. That Retune Speed causes the pitch center to be moved to D, while
still retaining the vibrato and expressive gestures. (Setting C # and B to
”Remove” is necessary to keep Auto-Tune 3 from trying to correct the
seriously flat tail of the last note to those pitches. See Chapter 3 for more
details.)
01-39 AT3 man layout RGB03/05/2001, 1:31 pm 12 
						

							13
Graphical Mode
The Graphical Mode is similar to the Automatic Mode in that it also
continuously tracks the pitch of the incoming sound and modifies the
output pitch to be closer to a desired pitch. But in the Graphical Mode, the
desired pitch is not a predefined scale tone, but rather is a graphical
representation of your desired pitch.
As in Automatic Mode, the rate of change towards the desired pitch is
controlled by the Retune control.
The key feature of Graphical Mode is the Pitch Graph display. On this
display, the vertical axis represents pitch (with higher notes towards the
top) while the horizontal axis represents time.
The red curve represents the original pitch contour of the input track,
while the desired target pitch or pitch contour is indicated in yellow.
01-39 AT3 man layout RGB03/05/2001, 1:31 pm 13 
						

							14
The horizontal grid lines represent scale pitches. The key annotation, scale
name, scale pitches and Scale Detune value are those defined in the
Automatic Mode. They do not affect the computations of the Graphical
Mode in any way. They are merely a reference to guide you in setting the
target pitches. If you wish to change them, you can select the Automatic
Mode and change the Key pop-up, Scale pop-up, or the Scale Detune
setting, respectively. (Changing the Scale Detune setting will also result in
the scale pitch graph lines moving up or down relative to the tracked
pitch.) Then, return to Graphical Mode.
The Graphical Mode also includes the Envelope Graph, which displays the
amplitude (loudness) envelope of the sound whose pitch is shown in the
Pitch Graph. The horizontal scale of this graph will either 1) show the
envelope of the entire extent of the pitch-detected sound or 2) align with
the horizontal scale and position of the Pitch Graph above it.
In Graphical Mode, you can draw the desired target pitches using line and
curve drawing tools. Complete image scaling and scrolling controls are
provided. A graphical editor allows easy editing, including cut, copy and
paste functions.
The basic steps you will perform in Graphical Mode are:
•In your host application, select some sound for processing.
•Bring up Auto-Tune 3. Set the buffer length for at least the number of
seconds from the beginning of the track to the end of the audio you
are going to tune. Press the Track Pitch button, then play back the
sound. The pitch will be detected and then displayed in the Pitch Graph
as a red curve.
•Create a target pitch function using the graphical tools and adjust the
Retune Speed for the desired effect.
•Press Correct Pitch and play back the sound. The pitch will be corrected
as specified.
01-39 AT3 man layout RGB03/05/2001, 1:31 pm 14