10.6

109Logic Pro Effects
Logic Pro Channel EQ Analyzer
The Analyzer uses a mathematical process called a Fast Fourier Transform (FFT) to
provide a real-time curve of all frequency components in the incoming signal. This is
superimposed over any EQ curves you have set. The Analyzer curve uses the same scale
as the EQ curves, making it easy to recognize important frequencies in the incoming audio.
This also simplifies the task of setting EQ curves to raise or lower the levels of frequencies
and frequency ranges.
The bands derived from FFT analysis are scaled logarithmically—there are more bands in
higher octaves than in lower octaves.
As soon as the Analyzer is activated, you can change the scaling from the default dynamic
range of 60 dB. Drag vertically on the scale to the right of the graphic display to set
the maximum value to anywhere between +20 dB and −80 dB. The Analyzer display is
always dB-linear. There are several additional Analyzer parameters in the Channel EQ
shortcut menus and the extended parameters.
Note: High Analyzer resolutions require significantly more processing power. High
resolution is necessary when attempting to accurately analyze very low bass frequencies,
for example. It is recommended that you turn off the Analyzer after setting EQ parameters.
Linear Phase EQ
Logic Pro Linear Phase EQ overview
The high-quality Linear Phase EQ effect is similar to Channel EQ, sharing the same
parameters and eight-band layout. See Logic Pro Channel EQ overview. You can copy
settings between them. If you replace Channel EQ with Linear Phase EQ (or vice versa) in
the same effect slot, the current settings are automatically transferred to the new EQ.
Linear Phase EQ uses a different underlying technology to Channel EQ that preserves the
phase of the audio signal. Phase coherency is always maintained, even when you apply
extreme EQ curves to the sharpest signal transients. This differs from Channel EQ, which
can introduce phase shifts of the signal that can have an audible (and often desirable)
effect on the sound.
A further difference between Channel EQ and Linear Phase EQ is that the latter uses a
fixed amount of CPU resources, regardless of the number of active bands. Linear Phase EQ
also introduces greater amounts of latency. See the Linear Phase EQ use, parameter, and
Analyzer sections.