Filter

The Filter removes everything on one side of a frequency, or keeps or removes a band around it. Drag across the graph to move the cutoff and scroll to add resonance, and the shape you hear follows your hand. It is the cleanest way to take rumble out of a track, and with the resonance up it is an instrument of its own.

When to use it

Put a high-pass on anything that has no business carrying bass: vocals, guitars, hats, pads. A low-pass tames a bright source or pushes a part into the background. Band-pass and notch isolate or remove one region, which is useful for lo-fi effects and for hunting a hum. For several bands on one curve use the Parametric EQ; for a boost or cut without removing anything, the Bell EQ.

Controls

Mode

High-pass cuts lows and keeps highs. Low-pass cuts highs and keeps lows. Band-pass keeps a band around the center and Notch cuts one. The two pass modes offer a choice of slope; band-pass and notch are a single second-order filter.

Cutoff / center

Where the filter acts. Drag horizontally on the graph or type a value. A new high-pass starts at 80 Hz, which clears the rumble out of most non-bass sources without touching their body.

Resonance / Q

How much the filter rings at the cutoff. 0.71 is flat at every slope. Higher values lift a peak at the cutoff, from a little emphasis to a whistle you can sweep through a part. In band-pass and notch the same control sets how narrow the band is. A 6 dB/oct filter has no resonance, so the control is disabled there.

Slope

How steeply the pass modes fall away: 6, 12, 18, 24, 36 or 48 dB/oct. 6 is gentle and first-order, 12 is the classic resonant filter, and the steeper settings cut like a wall while keeping the same Q behaviour at the knee.

Tips

• For cleanup, keep the resonance at 0.71 and choose the slope by ear: 12 or 18 dB/oct sounds natural, 48 dB/oct removes a region outright.
• Automate the cutoff for a sweep across a section; the filter follows the lane smoothly, and changing the slope while playing carries the sound over without a click.
• A notch with a high Q at the hum frequency removes it with little damage to the note around it.