F(ilter)12

Things sit better. What was crowding gets out of the way, what was hiding comes forward, and the record breathes without sounding like anything was done to it.

We are not going to tell you how. Do it over a mix you know well — that is the only explanation that has ever landed.

The same, turned all the way up. More of everything AURA already does to whatever it touches.

You will know within a bar whether a track wants it.

Swaps the panel to its dark colourway. Appearance only, and it saves with the session, so a project opens the way you left it.

Slows the rate the audio is sampled at.

The top goes, and what was up there folds back down into the audible range as new content. The fold is the point — it is what separates this from taking the top off with the filter, and why the two do not stack into the same result.

Coarsens the steps the audio is measured in.

It works on the size of the steps rather than on level, so it shows itself in tails and in the quiet material between hits. That is where the pair pulls apart: rate reshapes the top, bit reshapes the floor.

Twelve bits is as clean as this gets. It only goes down from there.

Takes the whole filter out of the way, so you can hear what it was doing without losing where you had it set.

Where in the spectrum the filter sits.

The further it works, the more it drives and the more it sings, without you adding anything to make that happen.

It is also the anchor for the Q SHAPE row — those peaks and dips sit at ratios of wherever this knob is, so the whole formation travels with it.

This is the knob you will spend the most time with, and the first place to look when you want to automate the filter in your DAW.

Low-pass, high-pass, band-pass, notch, morph — each drawn as its own response curve.

MORPH is the one that is not obvious. It runs one knob from a closing low-pass, through untouched, to an opening high-pass — so on morph the middle of POSITION's travel is the neutral place, and the two halves go opposite ways. The resonance grows toward both ends with it, so the extremes sing and the middle stays out of the way. On the other four the knob sweeps a corner and the ends are the extremes.

Two choices in one list: 12 or 24 dB per octave, clean or dirty.

Dirty feeds the circuit's own distortion back through itself. Slope and Q SHAPE are separate controls, so a steep dirty filter can also be a wah.

It opens on 24 dirty. There is no neutral starting point here on purpose.

Resonant nodes riding on top of the filter, placed at ratios of the cutoff so the whole formation sweeps with POSITION rather than staying nailed to a frequency.

• Plain no nodes. The filter's own resonance and nothing added.
• Wah one strong peak right at the cutoff, with a shallow dip just over an octave above it. The body underneath stays — a boost, so the lows do not leave when you sweep it.
• Vowel four peaks spaced the way a formant table spaces them.
• Comb peaks and nulls alternating on even spacing, seven of them across the range.
• Scoop a smile. Both ends lifted and the cutoff itself pulled down between them.
• Hollow a peak below the cutoff with a deep null immediately above it, and a lift again at the top.
• Twin two peaks, far enough apart to hear as two rather than as one wide one.
• Phaser five notches spread across the range. Cuts only, no boosts.

Every node sits between roughly a third of the cutoff and just under three times it. Further out than that and a node lands in the filter's own stopband, where the shape stops being audible at all.

This row and the cutoff row are independent. Any of the eight sits on any of the five.

• Drive how hard the signal is pushed into the crush. It sets the level that lands on the quantiser's rails, and the gain comes back off afterwards, so driving it is character rather than volume. 0 to 18 dB, opens at 0.
• Reso how hard it sings. 0 to 100 %, opens at 25.
• Q how narrow that singing is, and how tight the Q SHAPE nodes sit with it. It drives a peaking section right at the corner, so it is audible on every shape including PLAIN. 0 to 100 %, opens at 35.
• Mix how much of the whole thing you keep against what went in untouched. 0 to 100 %, opens at 100.

DRIVE is the odd one out in this row. It sits with the filter knobs but it works on the crush stage, so it is the crush pair's third control in everything but position.

RESO and Q are the pair to learn together. A wah at low Q is a broad sweep; the same wah at high Q is a point.

RESO scales the filter's whole resonance behaviour rather than setting one fixed value, so the character holds across the sweep instead of drifting as POSITION moves.

Hands the filter to your song's clock.

Locked to the arrangement rather than free-running: it moves only while the transport moves, it stops and returns to the start when you stop, and the sweep lands in the same place in the bar wherever you drop the playhead. On every shape but RANDOM, bar 9 looks like bar 1 and the same eight bars bounce the same way twice.

RANDOM is the exception, and worth knowing before you print. It draws a fresh value every time the cycle turns over, and that draw does not reset with the transport — so it does not repeat from take to take. Commit it to audio when you get one you like.

Hands the filter to a signal instead of a clock.

Same shapes, different driver. Here the shape is a path rather than a cycle: the follower walks it from rest to fully engaged and back, so a ramp is plain travel, a triangle pumps up and back, and a square gates.

The shape the filter opens and closes in, drawn rather than named.

Two pairs are worth separating. The ramps differ in which end snaps — RAMP UP climbs then snaps shut, RAMP DOWN snaps open then falls away — and the vertical edge in the drawing is the snap. The two squares differ only in which state they start in. The rest are what they look like, except that the triangle rises first.

Cuts the shape into a stair instead of a slide. Smooth reads as SMTH in the box.

Bends one shape into the next.

At 0 you get the shape you picked; turning it up walks it toward its neighbour. The seven tiles are points on a continuum, not seven fixed settings.

How quickly the filter travels once something is moving it, and how quickly it comes back.

They shape the filter's travel under either mover. How eagerly the follower itself decides to move is a separate thing, and that is REACT.

The division the cycle runs at.

4 bars down to 1/16 straight, plus 1/4 and 1/8 dotted, and 1/4, 1/8 and 1/16 triplet. It reads the host's tempo, so it follows a tempo change rather than needing to be reset.

Which notes SWING pairs up before it stretches them.

16TH and 8TH do nothing until SWING is off 50. QUINT does not work that way — it is a fixed three-against-two and ignores the SWING knob entirely, so it is the one setting here that changes the feel on its own.

Pushes the cycle off the grid the way an MPC does. 50 is straight, on 16TH and 8TH — QUINT sets its own ratio and this knob stops applying.

The clock itself stays exact underneath — the timing is displaced deliberately rather than allowed to drift.

Sends the sweep up from the filter, down from it, or both ways.

POSITION is the origin. On UP the knob is the floor of the sweep, on DOWN the ceiling, on BOTH the centre — so switching this moves where the same setting sits without you touching the big dial.

How far the sweep travels from where POSITION is sitting.

Measured in octaves, so the same setting is the same musical distance wherever on the dial you are working.

Every dial on the panel prints whole numbers, and this is the only one that opens on a fraction — so it reads 2 while it is sitting at 1.5, and a nudge or two will not change what it says.

What the follower listens to.

• Input the material itself. An envelope filter with nothing to route.
• Sidechain the external bus.

Which track feeds that bus is chosen in your DAW. No plug-in can see the host's routing, so that end of it is always the host's job.

Narrows what the follower hears to a band of the source.

It changes what drives the filter and never what you hear — nothing on this row is in the audio path. On INPUT it is the useful one: LOWS gives you kick-driven motion off the material itself, without setting up a send.

Which way the filter travels as the source gets louder.

• Up a louder source pushes the filter open. The envelope-filter move.
• Down a louder source pulls it shut. The pump.

How eagerly the follower makes up its mind.

Three settings and no milliseconds — it is a feel. The milliseconds are ATTACK and RELEASE.

How far the follower moves the filter.

The two movers name this the same thing and measure it differently: the clock's AMOUNT is in octaves, the follower's is a percentage.

The heavy line is the filter. Behind it is what is going in and what is coming out.

The field of pixels is AURA: green where it is adding, red where it is taking away, and nothing at all where it has no opinion. That last part is the one to watch — an empty stretch is the plug-in telling you it left that band alone.

Anything on this panel that is not affecting the sound is not on screen, so with nothing playing there is nothing drawn.

The same plot in its own window — 720 by 420, centred, and a fixed size.

Bigger than the strip on the panel, and with the scales printed on it: dB down the side, frequency along the bottom. For when you want to know exactly what is happening rather than feel it. The panel's own display goes dark while it is up.

Brings the walkthrough back whenever you want it.

It runs itself the first time the plug-in is opened on a machine, and says the same things this page does, a step at a time, pointed at the control it is talking about.

Click any knob and it is selected. Up and down then move it by one of whatever it reads out, and shift holds that to a tenth.

Drag to get near a value, arrow to land on it. The auto filter's AMOUNT is the one exception — its whole range is four octaves, so a step of one would be a quarter of the travel. It moves by a tenth instead, and a hundredth with shift.

Drag the window's corner to make the panel smaller, down to four fifths.

Every part of it scales together, so nothing shifts or reflows on the way down. It does not go bigger. It is already the size it was drawn at.