10.6

221Logic Pro Instruments
Rotate to randomly alter the pitch of each note and the filter cutoff frequency.
Much like polyphonic analog synthesizers, all three oscillators maintain their specific
frequency deviation from each other, but the pitches of all three oscillators are randomly
detuned by the same Analog amount. For example, if the Analog detuning is set to around
20%, all three oscillators (if used) randomly drifts by 20%.
Note: If ES2 is set to Mono or Legato keyboard mode, the Analog parameter is effective
only when Unison is turned on. In this situation, Analog sets the amount of detuning
between the stacked (unison) voices. If the Voices parameter is set to 1 and/or Unison
is not active, the Analog parameter has no effect. For more information about these
parameters, see Set the Logic Pro ES2 keyboard mode.
Stretch tuning in Logic Pro ES2
The (coarse) Frequency knob of each oscillator enables you to tune oscillators 1, 2, and
3 in semitones or octaves. The (fine tune) Frequency parameter enables you to fine-tune
each oscillator in cents (1/100th of a semitone). Precise detuning between oscillators
can result in beats, or phasing, between the oscillator frequencies. The higher the played
frequency/pitch, the faster the phasing beats. High notes, therefore, may seem to be
somewhat out of tune in comparison with lower notes.
CBD (Constant Beat Detuning) can be used as a corrective tool to even out the beating
between oscillators, or it can be used as a creative tool to emulate stretch tuning. The
latter can be particularly important when you use an ES2 sound alongside an acoustic
piano recording. This is because acoustic pianos are intentionally tuned “out-of-tune”
(from equal temperament). This is known as stretch tuning, and results in the upper and
lower keyboard ranges being slightly out of tune with the center octaves but harmonically
“in-tune” with each other.
Detuned oscillators periodically beat against each other at a certain frequency. CBD sets
the beating frequency between low and high notes or retains a constant beating frequency
across the keyboard range. Choose a CBD value to detune the harmonics/beating of
low note frequencies in a ratio proportionate to the fundamental tone of the upper note
frequencies.
CBD offers five values:off, 25%, 50%, 75%, and 100%. If you choose 100%, the phasing
beats are almost constant across the entire keyboard range. This value may, however, be
too high, because the lower notes might be overly detuned at the point where the phasing
of the higher notes feels right. Try lower CBD values in cases where the bass notes are a
little too far out of tune with the upper keyboard range.
The reference pitch for CBD is C3 (middle C):its (de)tuning is constant, regardless of the
chosen CBD value.