Filter block

Filter: supported by which Fractal Audio products?

• Axe-Fx II: yes.
• FX8: yes.
• AX8: yes.

X/Y-switching in the Filter block

• Axe-Fx II: no.
• AX8: yes.
• FX8: yes.

Filter applications

The Filter effect is a very versatile effect. Possible applications:

• one-band equalizer
• boost the input of an amp block
• boost the signal level for leads
• high-pass or low-pass filter
• envelope filter

Here's an example, emulating the Eric Clapton / Fender Mid-Boost: "Use the Filter block. Since the max boost is 25 dB set the filter order to 4th which will give you a maximum of 24 dB. Set the type to Peaking. Set freq to 500 Hz. Vary gain and Q to taste." source

Notes about Filter types

Variable-Q Filter

The Filter block provides Variable-Q EQ. Many “classic” graphic equalizers use variable-Q designs which may be more familiar to some users as opposed to constant-Q filters. In the Filter block this type is selected by choosing the “Peaking2” type.

Analog Shelving EQ

The Filter block provides “Lowshelf 2” and “Highshelf 2” EQ types. These types recreate the analog shelving filters found on classic mixing consoles. These filters are somewhat quirky and exhibit “overshoot” which gives them a certain musical quality. Set the Q between 0.5 and 0.707 to recreate those classic sounds or experiment with the Q for different amounts of overshoot. These filter types are great for getting that massive sound associated with passive equalization.

Tilt EQ

Tilt EQ is a slope filter that allows broad adjustment of the tone using just two parameters: Frequency and Gain. The Gain parameter sets the maximum gain of the filter relative to the center frequency. For example, a gain of 10 dB would set the maximum gain to 10 dB. The gain at the center frequency would be 0 dB and the minimum gain would be -10 dB, therefore a total of 20 dB of EQ would be applied.

Notch

Fractal Audio:
"Gain doesn't apply to a notch filter. Only frequency and Q are relevant." source

Envelope Filter (Auto Wah)

There's no dedicated Envelope Filter (Auto Wah) effect block. You can achieve this effect by attaching an Envelope to a Filter (or Wah) block.

You'll find examples in here, here and on Axe-Change. Or try the "Psychadelic Duck" preset (Axe-Fx II).