Apple Logic Express 7 - Manual (Page 45)

Chapter 6 Filter 45
LFO: the wave shape used for LFO oscillation is determined by the Waveform buttons.
The choices are: descending sawtooth (saw down), ascending sawtooth (saw up),
triangle, pulse wave, or random (random values, Sample & Hold). Once you’ve selected
a waveform, you can shape the curve with the Pulsewidth knob. Use the Frequency
knobs to define the desired LFO frequency: Coarse sets a value between 0.1 and
10,000 Hz, Fine lets you adjust it in smaller increments. The Speed Mod. (Speed
Modulation) knob is used to modulate the LFO frequency independently of the input
signal level. If the input signal exceeds the Threshold level, the modulation width of the
LFO increases from 0 to the value specified for Modulation. You can also define the
amount of time this process takes, by entering the desired value with the Delay knob. If
the Sync button is activated, the waveform is started at 0° as soon as the Threshold is
exceeded.
Whenever you use the AutoFilter as a stereo plug-in, you can determine the phase
relationships of the LFO modulations on the two stereo sides, with the Stereo Phase
knob.
If you active the 001/011 button of the Autofilter plug-in, you will have access to the
following five parameters:
The Volume parameter can lower the Volume by as much as
−
50 dB, allowing you to
compensate for higher levels when using Distortion, for example. If you switch Beat
Sync to On, the LFO is synchronized to the sequencer’s tempo. The speed values
include bar values, triplet values and more. These are determined by the Rate slider
directly below Beat Sync. Use Sync Phase to shift the phase relationship between the
LFO and the sequencer. Dry Signal sets the level ratio/portion of the non-effected (dry)
signal.