Introduction Modules Audio Filters

Filters

Usine provides a wide range of audio filter modules, from classic analog emulations to physical modelling and spectral processors. This page summarizes all available filters to help you choose the right one for your needs.

Comparison Table

Module	Topology	Poles	Types	Character
Simple	Biquad (Cook/RBJ)	2	LP, HP, BP, Notch, Low Shelf, High Shelf, Peaking	Clean, general-purpose, standard EQ curves
One Pole	IIR 1st order	1	LP, HP	Simple, gentle 6 dB/oct slope, very CPU-efficient
Biquad	Direct biquad	2	User-defined	Raw coefficient control (a0, a1, a2, b1, b2) for advanced use
Butterworth	Cascaded biquad	1-64	LP, HP	Maximally flat passband, variable order (3-96 dB/oct), CPU-efficient
Linkwitz-Riley	2x Butterworth	4	LP, HP	Crossover filter with flat summed response, 24 dB/oct
FIR	FIR (windowed sinc)	N/A	LP, HP, BP, BS, User impulse	Linear phase, variable length (128-1024), multiple window functions
Equalizer	Multi-band biquad + cascaded shelving	2 per band / 1-16	LP, HP, BP, Notch, Low Shelf, High Shelf, Peaking, Plateau	Up to 64 bands, per-band type selection, array I/O for all parameters
Multi Band Pass	Parallel biquads	2 per band	BP	Up to 128 parallel bandpass filters, array-driven
DC Blocker	HP (very low)	1	HP	Removes DC offset from audio signals

Analog Emulations

Filters that model the behaviour of classic analog synthesizer circuits, each with a distinctive sonic character.

Module	Emulates	Poles	Types	Character
Moog	Moog Ladder	4	LP	Warm, round, classic fat bass, polynomial clipping
Steiner SVF	Steiner-Parker SVF	2	LP, HP, BP, Notch, Peak	Versatile, symmetric tanh drive, clean to gritty
Korg MS-20	Korg MS-20 Sallen-Key	2	LP, HP, BP	Aggressive, screaming resonance, asymmetric diode clipping
Diode Ladder	Roland TB-303	4	LP, BP	Squelchy, acid, soft diode saturation in feedback
Oberheim SEM	Oberheim SEM SVF	2	LP, HP, BP, Notch, Morph	Smooth, musical, continuous morphing between filter types

Spectral & Vocal

Module	Topology	Character
Formant	10th order all-pole	Discrete vowel filter (A, E, I, O, U), pre-computed coefficients
Formant Morph	3 parallel biquad BP	Continuous X/Y vowel plane with smooth interpolation between all 5 vowels
Vocoder	Analysis/Resynthesis	Classic vocoder effect, analyzes one signal and imposes its spectrum on another

Physical Modelling & Resonance

Module	Topology	Character
Comb	Delay line + FF/FB	Feedforward + feedback comb, flanging, Karplus-Strong building block, metallic resonances
Waveguide	Karplus-Strong	Plucked string model, tuned delay with lowpass damping, works as filter or synth
Resonator	8 parallel biquad BP	Modal filter bank with harmonic, metallic, drum, or string partial ratios

Dynamic

Module	Topology	Character
Dynamic EQ	Envelope follower + biquad	Auto-wah (freq mode) or dynamic EQ / de-esser (gain mode), bandpass or peaking

Choosing the Right Filter

For subtractive synthesis:

Moog for warm, fat basses
Korg MS-20 for aggressive, screaming leads
Diode Ladder for acid squelch lines
Steiner SVF or Oberheim SEM for versatile, clean filtering

For mixing and mastering:

Equalizer for versatile multi-band EQ combining all filter types (peaking, shelves, plateau) with array control
Butterworth for steep, clean crossovers
Linkwitz-Riley for phase-coherent crossover networks
Dynamic EQ for frequency-selective compression or de-essing

For creative effects:

Comb for flanging and metallic textures
Waveguide for plucked string and resonant body effects
Resonator for bells, gongs, and tuned percussion
Formant Morph for vocal morphing and talking effects
Vocoder for classic robot voice

For utility:

Simple or One Pole for basic frequency shaping
DC Blocker for removing DC offset
FIR for linear-phase filtering