Reference Manual

290 Live Audio Effect Reference
22.2 Auto Filter
The Auto Filter Effect.
The Auto Filter effect provides classic analog filter emulation. It can be modulated by an enve-
lope follower and/or an LFO to create moving filter effects. The envelope follower can track
either the filtered signal or an external sidechain source.
There are four different filter types: lowpass, highpass, bandpass and notch. For each type, the
X-Y controller adjusts frequency (to adjust, click and drag on the X-axis) and Q (also called res-
onance; to adjust, click and drag on the Y-axis). You can also click on the Freq and Q numeric
displays and type in exact values.
Low Q values create a broad filter curve, while higher values introduce a narrow, resonant peak
to the sound. With bandpass filtering, Q sets the bandwidth of the passed signal.
The Quantize Beat control applies quantized modulation to the filter frequency. With Quantize
Beat off, frequency modulation follows the control source. Turning this feature on updates the fil-
ter modulation rhythmically with ”stepped” changes that track the master tempo. The numbered
buttons represent 16th notes, so, for example, selecting ”4” as a beat value produces a modula-
tion change once per beat.
The Envelope section controls how the envelope modulation affects the filter frequency. The
Amount control defines the extent to which the envelope affects the filter frequency, while the
Attack control sets how the envelope responds to rising input signals. Low Attack values cause
a fast response to input levels; high values integrate any changes gradually, creating a looser,
slower response. Think of it as adding inertia to the response.