CrystalKarat

CrystalKarat presents

Forge: multiband saturation that designs its own bands

Multiband saturation that designs its own bands

Play it four seconds of your track. Forge measures where the energy lives and lays out its own crossovers, drive and character to match. Then it hands you six bands, ten saturation characters and a modulation deck to take it anywhere.

VST3 · Windows & macOS · Perpetual license · 7-day trial, no card

Forge's interface: four bands across the spectrum, each with its own saturation character, and the FORGE core glowing at 82%.

Most multiband saturators make you guess where the bands go. Forge listens first.

Analyze

Four seconds. Then it designs itself.

Press Analyze and play your track. Forge measures every band's level, peak and crest factor, the spectral tilt and transient rate, and a fixed 24-bin spectrum that ignores the crossovers it is about to replace.

Then it decides. Wide-band material gets more bands; bass-heavy material gets its resolution down low, where the content actually is. It never overwrites you: Influence blends between your settings and its suggestion, and Undo restores everything from before the last analysis.

  • Freq SplitBand count and crossovers only. One band per two and a half octaves of real content, each holding an equal share of the energy.
  • WarmSofter transients and gentler drive. Tube, Warm Tape and Clean Tape, low to high.
  • PunchSharpened transients and full drive, with Transformer through the lows and mids.
  • CrushDrive at 1.6×: Tube into Hard Distortion into Destroy, at 4× oversampling.
  • MasterGentle glue at half drive, light transient softening, Transformer to Clean Tape.
Source
3 bands · Full mix
Analyze target
100%
30501002005001k2k5k10k+12 dB+24 dB+36 dB01WARM TAPE02WARM TAPE03WARM TAPE
Character
Warm Tape
Drive
+0.0 dB
Dynamics
+0
Mix
100%
Output
+0.0 dB

Press Analyze. Forge listens for four seconds, then designs the bands.

The demo runs Forge's own layout and voicing rules, ported from the plugin, on typical spectra for each source.

The FORGE knob

One knob, or a hundred.

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.

When you want the hundred, they 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.

Every band, harder
01Tube+14.7 dB
02Transformer+26.7 dB
03Warm Tape+19.7 dB
04Soft Clip+10.7 dB

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.

Harmonics

45.1% THD

Output level

+0.0dB

Measured through Forge's saturation code, ported to your browser. With Auto Gain on, the output tracks the input, so turning up drive changes the character and not the volume. Switch it off to hear how much louder saturation alone would make it.

Ten characters

Tape, tube, iron, amp. Then the dangerous ones.

Any character on any band, mixed freely across the spectrum. Every one is level-calibrated, so switching between them changes the colour and not the volume, and drive keeps a little of its level as it rises, the way an analog stage does.

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.

Character

Transformer

A cubic soft clip on a flux model: bass saturates the core before treble.

Best forIron, punch, the drum bus

+18.0 dB
0
Phase-flat bands

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. It is an easy detail to miss and an expensive one: drag the Mix below to see what it costs.

Dry path without the bands' phaseForge, phase matched
50%
501002005001k2k5k10k0 dB-12 dB-24 dB-36 dB

Computed for Linkwitz-Riley crossovers at 140 Hz, 700 Hz and 4.2 kHz. The deepest dip on the red curve moves with Mix; 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.

A dry path that matches

The dry blend and the sub-bass passthrough get the same all-pass and a whole-sample delay match, so Mix at any setting blends cleanly instead of combing.

Verified, not asserted

Both are covered by automated tests in Forge's build. Integer oversampler latency keeps the alignment exact at every quality setting.

Inside every band

Six bands. Each one a whole instrument.

Split a band with the + tab, drag crossovers anywhere from 20 Hz to 20 kHz, and 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.

Forge's band deck: character with its transfer scope and harmonics, saturation knobs, and the Pulse, Echo, Insert and Width sections.
Shape
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
Dynamics
Soften or sharpen transients before they hit the shaper, ±15 dB
Pulse
A per-band tremolo up to 500 Hz, into ring-mod territory
Echo
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
Insert FX

A complete effect inside each band, after the shaper: a phaser on the mids only, a tempo-synced delay on the air, a compressor inside the low band's saturation. Switching type never allocates, so even the type is automatable.

  • Filter
  • Delay
  • Chorus
  • Flanger
  • Phaser
  • Compressor
  • Bit Reducer
Wobble

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 four bars: two movements one shared oscillator cannot make.

Synced to your host's tempo by default, free-running when you want texture instead of rhythm. Draw your own with Custom, or start from nine ready-made wobbles.

Filter sweep
Filter sweep
Ready-made wobbles
Pattern / Filter

Sweeps a resonant filter around a pivot you choose.

Shape & speed
Pattern shape
Rate
Sync 1/8
80%

A low-pass rocking on eighths, with a half-note accent on the level.

Master

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.

Forge's master deck: filter, compressor, stereo with Mid/Side, sidechain and engine oversampling.
Mid/Side, all the way through

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.

Sidechain, band by band

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.

Sub passthrough

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.

A master section

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.

Under the hood

Clean at 1×. Honest at every setting.

The analog characters are voiced waveshapers, and Forge says so. What makes them sound right is the engineering around them, measured below with Forge's own saturation code.

Alias-suppressed at 1×

Antiderivative antialiasing, no oversampling tax

Tape, tube, transformer, amp, both distortions and soft clip evaluate the integral of their curve rather than the curve itself, so most aliasing never happens at the native rate. Bit Crush and Destroy stay oversampled by design.

5k10k15k20k-25 dB-50 dB-75 dB
Pointwise shaperForge, ADAAFolded alias

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 -71 dB; first-order ADAA does least right at the top, near Nyquist, which is what oversampling is still there for.

Frequency-aware

Bass hits the core first, like real iron

Transformers and tape saturate on flux, the integral of the signal, so low frequencies drive the core harder. Transformer and Warm Tape model it. Same level, same drive, two frequencies:

55 Hz3rd harmonic -6.8 dB
3 kHz3rd harmonic -29.7 dB

Transformer at +12 dB, both tones at −6 dBFS. Dashed: the same gain with no saturation. The flux model is identity until the shaper bends, so clean signals pass unchanged.

It breathes like hardware

Component tolerance offsets each channel's drive and bias by a deterministic, per-instance amount: the small left-right mismatch that reads as analog width. Sessions recall it exactly, and zero is bit-identical channels.

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 integer latency reported to the host at every setting. Bit Crush's rate is fixed in hertz, so presets sound the same at any rate.

Specifications

Everything, at a glance.

Bands
1 to 6, split and dragged on the display; 4th-order Linkwitz-Riley crossovers
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, 9 ready-made
Analyze
5 targets, Influence blend, 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 the host in whole samples at every setting
Parameters
199, every one automatable
System
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 once activated

Validated with pluginval for every release. Pro Tools (AAX) and Logic Pro (Audio Units) are not supported yet.

13 factory presets
Vocal
Vocal Air
Bass
Tube Drive · Bass Tighten
Drums
Transformer Iron · Amp Crunch
Bus
Warm Glue · Clean Tape · Wide Glue · Bus Compressor
Master
Mastering Glue · Linear Master
Creative
Bit Crush · Lo-Fi

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 once activated
  • 13 factory presets across six categories
  • Your key by email and in your account, at once
Questions

Before you buy.

Which DAWs does Forge work in?
Any host that loads VST3 plugins on Windows 10 or later (64-bit) or macOS 10.13 or later, on Apple silicon or Intel. Pro Tools needs AAX and Logic Pro needs Audio Units; Forge does not ship either yet.
How does activation work?
Open Forge, paste your key into its activation card and press Activate. That registers the machine once. From then on Forge checks a signed activation file on your computer, so it opens sessions without a connection. It renews that file in the background when you are online, and needs to reach the license server at least once every 30 days.
How many computers can I use it on?
One at a time. To move Forge, deactivate it from the plugin's About panel, or from your account if the old machine is gone, then activate it on the new one.
Why do I need an account?
Your CrystalKarat account holds your license key, the machines it is active on and the installers, so nothing gets lost in an inbox. It is created as part of checkout, or when you start a trial.
Can I get a refund?
Forge is delivered the moment you pay, so at checkout you ask for immediate delivery, which ends the 14-day cancellation period that otherwise applies to online purchases. Your statutory rights are unaffected: if Forge is faulty or not as described, you are entitled to a repair, a replacement or a refund. The free trial is there so you can check Forge on your own system first.
Does Forge model specific hardware?
No. Its characters are voiced after tape, tube, transformer and amp circuits rather than modelled on particular units. Transformer and Warm Tape include a flux model so bass saturates first, as real iron does, but there is no tape transport or hysteresis model, and we would rather say so than imply it.
Is there a trial?
Yes: 7 days of the full plugin, free, with no card. Start it here and your trial key and the installers are ready at once. When it ends Forge goes quiet until you activate a purchased key, and nothing is charged. There is one trial per account and per computer.

Stop guessing where the bands go.

Four seconds of listening, six bands, ten characters and one molten core.