Filter types
> Each band can take one of 18 filter shapes — from the classic mixing toolkit to specialty types built for mastering and resonance work. Right-click any band disc to choose.
Each band can take one of 18 filter shapes — from the classic mixing toolkit to specialty types built for mastering and resonance work. Right-click any band disc to choose.
The classics
LowCut
High-pass: cuts everything below the band frequency. The slope knob picks how steep (6 to 96 dB/oct). 0 dB/oct disables the band.
LowShelf
Shelves gain below the band frequency. Slope cascades multiple RBJ shelves for sharper transitions.
Peak
Bell shape. The everyday boost-or-cut band. Q sets the width; for steeper bells the slope knob cascades multiple peaks at the same frequency.
HighShelf
Same as LowShelf but above the frequency.
HighCut
Low-pass: cuts everything above the band frequency.
Air
Slew-limiter-derived high-band sweetener. Softens sibilance without phase artefacts; slope and Q are inactive.
PultecShelf
Vintage Pultec EQP-1A curve — an asymmetric boost-and-cut shelf cascade that adds the famous low-end "thump and tightness". See Pultec low-end for the dedicated Pultec stage that lives alongside.
AllPass
Passes all frequencies at unity gain but rotates phase 360° around the band frequency. Useful for time-aligning multi-mic captures or correcting comb-filter problems in parallel chains.
Surgical and specialty
BandPass
Lets through a window around the band frequency; cuts everything else. The slope sets the flank steepness.
Notch
Very narrow cut. Q sets the depth-width compromise; slope cascades multiple notches for a wider, deeper V.
TiltShelf
A "see-saw" of two opposing shelves around the band frequency. Boost the lows by 3 dB and cut the highs by 3 dB in a single move. Slope sets how steep the cross-over is.
AllPassLow / AllPassHigh
Phase rotators biased below or above the band frequency. Subtle phase nudges useful for blending parallel processing.
Sword
A narrow Q×2 peak flanked by two notches — a "resonance digger" that lets you carve out a single harmonic without affecting its neighbours. Built for taming room modes and synth resonances.
FlatTilt
A steeper see-saw with explicit flat plateaus outside the tilt region. Tilt the spectrum cleanly without bleeding into the band edges.
FlatTop
A flat-band-pass shape — two shelves that produce a level mid-band between two cuts. Use it for isolating a frequency range cleanly without the slope of a BandPass.
BrickwallLP
96 dB/oct Butterworth low-pass. The slope knob is ignored — this type is always maximally steep.
BrickwallHP
96 dB/oct Butterworth high-pass. Same — always maximally steep.
Tips
- For most mixing work you'll live in Peak + LowCut + HighCut. Reach for Sword and Notch when you've isolated a specific resonance.
- The PultecShelf type is independent of the per-band Pultec card (see Pultec low-end) — the card adds the EQP-1A "trick" on top of any shelf type, while the PultecShelf type is the shape itself.
- BrickwallLP/HP are useful for cinematic LFE management or as a creative effect; they introduce 96 dB/oct of slope regardless of where the slope knob sits.
See also
Band controls
> Each of the eight bands has the same set of static controls — frequency, gain, Q, filter type, slope, on/off, and routing. Everything else (dynamics and the per-band character stages) layers on top
Filter slopes
> Every cascading filter type in Outboard-EQ has a per-band slope, from a single biquad (6 dB/oct) up to an eight-stage Butterworth cascade (96 dB/oct). Right-click the band disc → Slope to pick.