Antares autotune4 Manual Do Utilizador
8
How Auto-Tune 4 detects pitch
In order for Auto-Tune 4 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 4 does exactly this: It looks for a periodically repeating
waveform and calculates the time interval between repetitions.
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 4 does exactly this: It looks for a periodically repeating
waveform and calculates the time interval between repetitions.
The pitch detection algorithm in Auto-Tune 4 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 inherent
and unpredictable delay that depends largely on what else your CPU is
doing at the time.)
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 inherent
and unpredictable delay that depends largely on what else your CPU is
doing at the time.)
Auto-Tune 4 was designed to detect and correct pitches up to the pitch C6.
(If the input pitch is higher than C6, Auto-Tune 4 will occasionally interpret
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 4 will detect pitches
as low as 25Hz (when the Bass Instrument Input Type is selected). This range
of pitches allows intonation correction to be performed on virtually all
vocals and instruments.
(If the input pitch is higher than C6, Auto-Tune 4 will occasionally interpret
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 4 will detect pitches
as low as 25Hz (when the Bass Instrument Input Type is selected). This range
of pitches allows intonation correction to be performed on virtually all
vocals and instruments.
Of course, Auto-Tune 4 will not detect pitch when the input waveform is
not periodic. As demonstrated above, Auto-Tune 4 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 4 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 4 be a bit more casual about what it considers “periodic.” Experiment-
ing with this setting will often allow Auto-Tune 4 to track even noisy
signals.
not periodic. As demonstrated above, Auto-Tune 4 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 4 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 4 be a bit more casual about what it considers “periodic.” Experiment-
ing with this setting will often allow Auto-Tune 4 to track even noisy
signals.
How Auto-Tune 4 corrects pitch
Auto-Tune 4 provides two separate and distinct ways to approach pitch
correction: Automatic Mode and Graphical Mode. The basic functionality of
each is described below.
correction: Automatic Mode and Graphical Mode. The basic functionality of
each is described below.