CrystalKarat presents
Forge: multiband saturation that designs its own bands
Multiband saturation that designs its own bands
Pick a character and play it four seconds of your track. Forge finds where your material divides and sets its own crossovers and slopes. It drives each band into that character at the level the band plays at, then matches the result to the loudness of what went in. After that, six bands, ten saturation characters and the Wobble modulation deck are yours to change.
VST3 · Windows & macOS · Perpetual license · 7-day trial, no card

Most multiband saturators make you guess where the bands go. Forge listens first.
Pick a character. Play four seconds. It designs itself.
Choose what you want the track to become and press Analyze. Forge listens, finds where your material naturally divides, and puts a band on every register it reaches: a vocal gets no sub band, a full mix gets the lot. Each crossover moves into the spectrum's own valley, so no kick or bass note is cut in two, and a deep valley earns a steeper slope.
Then it voices every band. Forge probes each band's own character across the levels that band plays at and sets the drive that adds exactly the distortion the character calls for: about 3% for Warm, half a percent for Master. Every band is rendered and trimmed back to its own level, and the whole result is matched to the loudness of what went in, so a louder result cannot pass for a better one.
Try another character and it re-voices from the same four seconds, no replay. Undo puts back everything it touched; your echoes, inserts and Wobble are never touched at all.
- WarmValve and tape on the lows and mids at about 3% distortion, softer transients, a rounder top, gentle 12 dB/oct crossovers.
- PunchIron and clean tape with sharpened transients, blended in parallel on the attack bands so the hits land harder and the dry attack survives.
- AirEven-harmonic sheen from biased valve on the presence and air, in parallel and brightened a touch. Everything below the mids stays dry.
- GritAmp driven into its clip on the mids, iron on the lows, a dry sub and a tamed top: attitude without fizz or mud.
- CrushHard distortion and wavefolding at 20 to 30% distortion, split at 48 dB/oct so the sub stays solid under the wreckage.
- MasterBarely-there density for a finished mix: 0.3 to 0.6% distortion per band, gentle 12 dB/oct crossovers and 4x oversampling.
- Bands OnlyPuts a band on every register the material reaches, each crossover in a valley of the spectrum, and leaves every band's sound as it is.
- Character
- Warm Tape
- Drive
- +0.0 dB
- Distortion
- —
- Dynamics
- +0
- Mix
- 100%
- Edges, dB/oct
- — · 24
Pick a character and press Analyze. Forge listens for four seconds, then designs the bands.
The demo lays out, voices and calibrates exactly as the plugin does, on typical spectra for each source. In the plugin, the spectrum and each band's loudness come from your own audio.
One knob drives every band at once.
Forge opens on one screen: the display, Analyze, and one big FORGE knob. It adds up to +24 dB of drive to every band at once, on top of whatever each band is already set to, so the whole engine runs hotter while the balance between bands holds.
The rest of the controls are one click away: every band carries a tab on the display that opens all of its controls, right where the band is.
FORGE
28% +6.7 dB
Drag, scroll or use the arrow keys. Double-click to reset.
The white line is each band's own drive. The FORGE knob adds the same amount on top of all of them, so the balance you set between bands survives.
45.1% THD
+4.7dB
Measured through the same saturation as the plugin, running in your browser. Auto Gain starts off, as in the plugin, so this is how much louder saturation alone makes it. Switch it on and the output tracks the input, so turning up drive changes the character and not the volume.
Tape, tube, iron, amp. Then the dangerous ones.
Any character on any band, mixed freely across the spectrum. Every one passes a clean signal at unity gain, so trying them at low drive changes the colour and not the volume. Driven, each keeps a little of the level it adds, the way an analog stage does, and how much is part of its character.
Bias scales the two halves of the wave apart for even harmonics without more drive. Turn it up below and the even harmonics, drawn in amber, climb.
Transformer
A soft clip on a flux model: bass saturates the core before treble.
Best forIron, punch, the drum bus
Blend it at 50%. Hear nothing cancel.
Parallel saturation only works if the dry signal lines up with the wet one. In a multiband plugin that means matching the phase the crossovers leave behind, not just the latency. Drag the Mix below, or change the slope, to see what it costs when they do not.
Shown for crossovers at 140 Hz, 700 Hz and 4.2 kHz, all at the slope you pick. The red curve's dips move with Mix and slope; only a 6 dB/oct split, whose bands add straight back to the input, has no phase to match. Forge's dry path carries the same all-pass as the bands, so its line stays at 0 dB at every setting.
Deepest dip -45.1 dBvs0.0 dB
Bands that sum flat
Splitting off a band and then splitting the remainder leaves every band with a different phase. Forge re-applies each later crossover's all-pass to every earlier band, so the whole split recombines flat, with any slope on any crossover.
A dry path that matches
The dry blend runs through the same oversampler and all-pass as the bands, and the sub-bass passthrough gets the same all-pass and a matching delay, so Mix at any setting blends cleanly instead of combing.
Measured at every setting
Every release of Forge is measured at every oversampling setting, filter type and crossover slope: a 50% blend of clean bands stays within 0.1 dB from 100 Hz to 20 kHz.
Six bands, each with the full chain.
Split a band with the + tab, drag crossovers anywhere from 20 Hz to 20 kHz and give each one its own slope, from a gentle 6 dB/oct blend to a surgical 48. Every band gets the complete chain: dynamics, bias, character, pulse, clip, tone, echo and its own insert effect, with mute and solo to hear exactly what it is doing.

- Drive
- 0 to +36 dB into the band's character
- Bias
- Even harmonics, independent of drive
- Tone
- ±6 dB tilt around 250 Hz and 4 kHz
- Clip
- A falling ceiling after the shaper
- Mix
- Parallel saturation, per band
- Width
- Per-band stereo width in Mid/Side mode
- Dynamics
- Soften or sharpen transients before they hit the shaper, ±15 dB
- Pulse
- A per-band tremolo, from slow pulsing at 0.1 Hz to audio-rate AM at 500 Hz
- Feedback
- Comb, resonance or echo inside the band
- Time
- 1 ms to 1 s, or locked to the host tempo
- Follow
- Ducks the feedback while the source plays
A complete effect inside each band, after the shaper: a phaser on the mids only, a slapback delay on the air, a compressor on the low band alone, right after its saturation. You can even automate the effect type: switching it mid-playback causes no dropouts.
- Filter
- Delay
- Chorus
- Flanger
- Phaser
- Compressor
- Bit Reducer
Six destinations. Six oscillators. Nothing to patch.
Click a target, give it a shape and a speed, and set how far it moves. Every target runs its own pattern at its own rate, so a square tremolo on eighths can sit under a slow filter sweep across a whole bar: two movements one shared oscillator cannot make.
Synced to your host's tempo and locked to its bar by default, free-running when you want texture instead of rhythm. Draw your own with Custom, or start from eight ready-made wobbles.
Sweeps a resonant filter around a pivot you choose.
A low-pass rocking on eighths, with a half-note accent on the level.
Then finish the bus in the same plugin.
Stereo, sidechain, filters, a compressor and the engine's quality settings all live one tab away from the bands, on the Master deck.

Flip the engine into Mid/Side and the centre and the sides each get a complete band chain. Saturate the middle without smearing the sides, narrow the lows, widen the air.
An external key is split through the same crossovers as the audio, so each band ducks or expands against its own slice of the key, up to ±24 dB. The display draws every band reacting.
Everything below a frequency you choose stays bone dry and comes back phase-aligned. The low end holds still while everything above it gets worked.
High-pass and low-pass filters, a soft-knee compressor, output trim and a global mix after the bands. Finish the bus without reaching for another plugin.
Less aliasing at 1×, and bass that saturates first.
The analog characters are voiced waveshapers rather than circuit models. The engineering around them is what makes them sound right, and the charts below measure it with the same saturation that runs in the plugin.
Antiderivative antialiasing, no oversampling tax
Clean Tape, Tube, Amp, both distortions and Soft Clip switch on antiderivative antialiasing as soon as they are driven into their curve, so most aliasing never happens, even without oversampling. Below the curve they pass the signal untouched. Warm Tape and Transformer shape an integrated flux signal and, like Destroy, lean on the oversampler; Bit Crush aliases on purpose.
A 5 kHz tone into Soft Clip at +18 dB, no oversampling. Every peak off the 5 kHz series is a harmonic folded back from above 24 kHz. The fold at 3 kHz drops from -35 dB to -72 dB; first-order ADAA does least right at the top, near Nyquist, which is what oversampling is still there for.
Bass hits the core first, like real iron
Transformers and tape saturate on magnetic flux, which builds up most at low frequencies, so bass drives the core harder. Transformer and Warm Tape model it. Same level, same drive, two frequencies:
Transformer at +12 dB, both tones at −6 dBFS. Dashed: the same gain with no saturation. Until the shaper bends, the flux model leaves the signal unchanged.
Channel tolerance
Component tolerance, off by default, offsets each channel's drive and bias by a slightly different amount: the small left-right mismatch that reads as analog width. Each instance gets its own mismatch, sessions recall it exactly, and at zero both channels are identical.
Hear exactly what it adds
Solo or mute any band. Delta monitor swaps the output for wet minus dry, using the same phase-matched dry path as Mix, so you hear only what the saturation contributes.
Quality you can choose
Off, 2×, 4× or 8× oversampling, minimum-phase or linear-phase, with latency reported to your DAW at every setting so everything stays in time. Bit Crush's rate is fixed in hertz, so presets sound the same at any sample rate.
Everything, at a glance.
- Bands
- 1 to 6, split and dragged on the display
- Crossovers
- 6, 12, 24 or 48 dB/oct, set per crossover; Linkwitz-Riley from 12 up, flat-summing at every slope
- Characters
- 10, any one on any band
- Insert effects
- 7, one inside every band: filter, delay, chorus, flanger, phaser, compressor, bit reducer
- Modulation
- Wobble: 6 targets, each with its own oscillator, 7 patterns, 8 ready-made
- Analyze
- 6 characters plus Bands Only, from 4 s of audio: crossovers, slopes and every band's drive calibrated, then level-matched. Re-voices without replaying; one-step Undo
- Oversampling
- Off, 2×, 4×, 8×; minimum-phase or linear-phase
- Sidechain
- External key, split per band, compress or expand
- Stereo
- L/R or Mid/Side, per-band width, global width
- Master
- High-pass, low-pass, compressor, output, global mix
- Monitoring
- Per-band solo and mute, delta
- Latency
- Reported to your DAW at every setting, so tracks stay in time
- Parameters
- 204, every one automatable
- Format
- VST3
- Windows
- Windows 10 or later, 64-bit
- macOS
- macOS 10.13 or later, Apple silicon and Intel
- Interface
- 1200 × 800, resizable 75–150%, vector-sharp at any scale
- License
- Perpetual. One machine at a time, works offline for 30 days at a time once activated
Pro Tools (AAX) and Logic Pro (Audio Units) are not supported yet.
- Vocal
- Vocal Air · De-Harsh · Radio Voice · 8 more
- Drums
- Kick Punch · Parallel Smash · Tape Drum Bus · 10 more
- Bass
- Sub Harmonics · 808 Weight · Reese Phaser · 8 more
- Guitar
- Blues Breakup · High Gain Wall · Shoegaze Haze · 5 more
- Keys & Synth
- Rhodes Bark · Analog Heat · Acid Line · 7 more
- Bus
- Warm Glue · Analog Summing · Mix Punch · 7 more
- Master
- Mastering Glue · Master Air · Six Band Master · 7 more
- Lo-Fi
- Worn Cassette · Old Record · 12-Bit Sampler · 6 more
- Movement
- Wobble Bass · Trance Gate · Stereo Swirl · 6 more
- Creative
- Wavefolder · Spectral Zebra · Phase Melt · 6 more
Save your own alongside them; they are plain files in your Documents folder.
Multiband saturator
£39one-time
No subscription. No iLok. No dongle.
Secure checkout by Stripe. The trial needs no card. Either one creates your CrystalKarat account, where your key, activations and installers live.
What you get
- Forge for Windows and macOS, as a VST3
- A perpetual license: buy once, keep it
- One machine at a time, moved whenever you like
- Works offline for 30 days at a time once activated
- 100 factory presets across ten categories
- Your key by email and in your account, at once
Before you buy.
Which DAWs does Forge work in?
How does activation work?
How many computers can I use it on?
Why do I need an account?
Can I get a refund?
What does Analyze change, and can I take it back?
Does Forge model specific hardware?
Is there a trial?
Stop guessing where the bands go.
Four seconds of listening, six bands, ten characters and one molten core.