Mix Tools
EQDRIFT
Three modules, three different answers to the same question, and filters that do not cramp.
Free 10-day trial. The download is the whole collection, 22 plug-ins in one installer, so you can try every one; start EQDRIFT's trial from inside the plug-in when you are ready. Downloading does not start it, and trying one plug-in does not start the others.
- AU (macOS)
- VST3
- AAX
- macOS Universal
- Windows 64-bit
- v1.0.0
What it does
Three equalisers. One curve you can trust.
Every digital EQ built on the bilinear transform has the same flaw. The transform squeezes the whole infinite analogue frequency axis into the space below Nyquist, so a filter's upper skirt gets compressed toward the top of the band. A 10 kHz bell at 44.1 kHz reads low where the analogue prototype would still be at full gain, and a high shelf never quite reaches the gain you asked for. The usual workaround, oversample the EQ, treats the symptom.
EQDRIFT designs its sections a second way. Poles are placed by mapping the analogue poles straight through the exponential, which warps nothing. The numerator is then solved rather than transformed, by requiring the digital magnitude to equal the analogue prototype's at DC, at the corner and at Nyquist. In the top octave three points are not enough, so above a twelfth of the sample rate the remaining freedom goes to a least-squares fit over the whole top of the band, and nothing below it changes by a single bit. It costs a few extra transcendentals at design time and nothing per sample.
That is why Natural Phase, not Zero Latency, is the shipping default.
Frequency and Q are logarithmic across their whole travel, so equal movement of a control, or of a straight automation line, is an equal musical interval anywhere on it.
Key features
CLASSIC · 32 bands with dynamics on every one
Point at empty space and the band a click would make is drawn in full before it exists: a bell in the middle, a shelf at either end, a cut well below the line. Click to make it, pick its shape from pictures of the shapes themselves, and its card opens with frequency, gain, Q and dynamics. Sixteen shapes, slopes from 6 dB/oct to brickwall, six phase modes and per-band mid/side placement.
SPECTRUM · adaptive resonance suppression
Measures what the spectrum should look like around each frequency and pulls down whatever is protruding from it, only while it protrudes. It listens for resonances rather than harmonics, so the partials of a sung note are not mistaken for problems. The white line is not a gain curve: up to eight points, bells or shelves placed anywhere, set how hard it works at each frequency, and +6 dB doubles the cut there.
TRACK · pitch-following EQ
Estimates the fundamental of what is played and hangs EQ nodes off its harmonics, so a cut on the third harmonic stays on the third harmonic as the notes change. FOLLOW is multiplied by the tracker's confidence, so as the detector loses the note, nodes slide back to their manual positions rather than freezing somewhere arbitrary.
All three at once
Click a tab for one module alone; shift-click to run several in series, always TRACK, then CLASSIC, then SPECTRUM. The page in front of you draws what the others are doing as faint dashed lines in their own colours, and MIX blends the whole chain against a dry path delayed to match it, so a parallel blend never combs.
Modulation is silent
Every section is converted to topology-preserving form before it processes a sample. A direct-form biquad has no physically meaningful state: when its coefficients jump, the state that suited the old transfer function is wrong for the new one, and it clicks. TPT state is its two integrator voltages, which stay meaningful whatever the coefficients do.
The picture is the filter
The curve on screen, the linear-phase kernel and the recursive filters are all derived from the same coefficients. The kernel is sampled from the filters that are already running rather than designed a second time, so linear phase and zero latency cannot disagree about magnitude. The test suite checks the measured response against the drawn curve to within 0.05 dB.
Cascades that are actually Butterworth
Using 0.7071 for every section, which is common, gives a cascade 12 dB down at its nominal corner instead of 3, with a passband that droops for an octave above it. Every order from 2 to 16 is checked against the Butterworth magnitude to within 0.02 dB.
The interface
Audio
Audio demos for EQDRIFT are not published yet.
We would rather show you nothing than show you a demo that was not recorded through this plugin.
Measured
EQDriftTests, EQDriftPluginTests and EQDriftBench · Apple Silicon · 48 kHz · 512-sample blocks
- 10 kHz Q=1 +12 dB at 44.1 kHz: bilinear error
- 3.820 dB
- 10 kHz Q=1 +12 dB at 44.1 kHz: matched error
- 0.312 dB (12× closer)
- 20 kHz Q=1 −12 dB bell at 48 kHz: matched error
- 0.39 dB
- Measured response vs drawn curve
- within 0.05 dB
- Butterworth cascade accuracy, orders 2–16
- within 0.02 dB
- Frequency automation, step to step
- the same interval to within 0.0003 octaves
- CPU: 8 static bands
- 0.49 %
- CPU: 32 static bands
- 1.14 %
- CPU: all three modules at once
- 4.29 %
- Mix return with every module inert
- input to within 6e-08
- Test checks across both suites
- 2,315
- auval
- AU VALIDATION SUCCEEDED
- pluginval
- SUCCESS at strictness level 10, VST3 and AU
Figures are produced by this plugin’s own test suite and benchmark, on the hardware and sample rate named above. They are not estimates.
Controls
CLASSIC
- Point at empty space
- See the band a click would make, drawn in full before it exists.
- Click / click-drag empty space
- Make it: a bell in the middle, a shelf at either end, a cut well below the line. Drag to make it and place it in one gesture.
- Drag / Shift-drag / Ctrl-drag
- Frequency and gain / gain only / frequency only.
- Wheel over a node
- Q, multiplicative: shift for fine.
- Alt-click
- Delta-solo the band: hear only what it is doing.
- Double-click a node
- Remove it. Ctrl-click duplicates it; right-click opens the band menu, with split, copy and paste between instances.
- Band card
- Click a node to open it: shape, chosen by its picture, and stereo placement, ON, SOLO, FREQ, GAIN and Q. A cut has no gain, so its middle knob is SLOPE.
Dynamic bands
- Dynamic
- Static, or Downward Compress, Upward Expand, Upward Compress or Downward Expand. The mode chooses which side of the threshold engages the band and which way it then moves; the direction belongs to the mode, never to the sign of the gain.
- THRESH · RATIO · RANGE
- On a second card beside the band's. RANGE is how far the dynamics may move the band from its resting gain; the whole travel is shaded in, with the live curve moving inside it.
- ATTACK · RELEASE · KNEE · LOOK
- Timing, knee and look-ahead, with the sidechain source and LINK.
SPECTRUM
- Points
- Click to place one, a shelf near either end or a bell between, up to eight. Drag for frequency and sensitivity, the wheel for width, right-click for its shape, double-click to remove.
- LOW · HIGH
- The range it works in, as knobs or as the handles on the display. Outside it nothing is touched.
- DEPTH
- How hard a resonance is pulled down, on a squared taper: the middle of the knob is a moderate setting.
- FOCUS
- How readily a peak counts as protruding.
- SELECTIVITY
- How narrow a feature has to be.
- ATTACK · RELEASE
- How quickly a resonance is pulled down, and how quickly it is let go.
- QUALITY · DELTA
- Eco, Normal or High analysis resolution; DELTA plays only what is being removed.
TRACK
- TRACK · HARMONIC
- Attaches the node to the fundamental or one of its harmonics. Off, it is an ordinary fixed band.
- FOLLOW
- How completely a node follows, interpolated in log frequency and multiplied by the tracker's confidence.
- OFFSET
- Cents around the node's harmonic. Dragging a tracked node sideways changes this: it keeps tracking.
- SPEED
- How urgently the tracker follows small movement. Large note changes are followed quickly whatever it is set to.
- MIN · MAX
- The lowest and highest frequency the node may reach, however far the note goes.
- DYN · FREEZE · DELTA
- Act only while the tracked partial is above its threshold; hold the detected pitch; hear only what the tracked nodes are doing.
- Source
- Audio, Sidechain or MIDI. On a synth already driven by MIDI, guessing the notes back out of the audio is strictly worse than reading them.
Header and strip
- Phase mode
- Natural Phase by default; Zero Latency, Linear Phase, Ultra Linear, Hybrid Phase and Minimum Phase.
- Oversampling
- 1x to 32x. For dynamic bands and steep filters with a corner in the top octave; reports latency.
- DELTA · AUTO GAIN
- Hear only the difference CLASSIC is making; compensate the broadband level change its curve implies, so switching between two curves compares tone rather than loudness.
- HELP
- Rest the pointer completely still on a control for two seconds and a panel explains what it does and when to reach for it. Any movement closes it; HELP switches the panels off.
- ANALYZER · MIX · OUTPUT
- Pre, Post, both or off, with a pause; the instance's mix; CLASSIC's output trim.
- Presets
- A bank per page, which sets only that module, and EQDRIFT GLOBAL chains that set all three. A/B and copy from the header's right-click menu.
Technical details
- Formats, macOS
- AU · VST3 · AAX
- Formats, Windows
- VST3 · AAX
- Operating system
- macOS 10.15 or later · Windows 10 or later, 64-bit
- Architecture, macOS
- Universal: Apple Silicon and Intel
- Architecture, Windows
- 64-bit
- Plugin code
- Eqdr
- Version
- 1.0.0
- CPU
- 0.49 % for 8 static bands, up to 4.29 % with all three modules running
- Factory presets
- 98
A bank for each module, and loading one sets only that module: 46 for CLASSIC, from mastering and mix bus to vocals, drums, post and repair; 27 for SPECTRUM, by source and by problem; 15 for TRACK, each for a stated job. Ten EQDRIFT GLOBAL chains at the bottom of every page's menu set all three modules together.
Worth knowing
- Match EQ and resonance detection are implemented and tested in the DSP layer but are not yet reachable from the interface. They are not features of this release.
- Analog Phase is listed in the phase-mode menu but is not built yet: it currently sounds the same as Natural Phase.
- Mid/side bands always run on the recursive filters, never linear phase, even in the linear-phase modes.
Also in these bundles
COMPLETE COLLECTION
Get EQDRIFT as part of COMPLETE COLLECTION, 22 plugins worth 708 for 199.
199
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