Harrison Mastering EQ — Free Download
A mastering EQ plug-in with 31 bands, flat-top filtering, and intuitive draw-style control, designed for transparent mix finalization.

Purpose
The Harrison Mastering EQ functions as a final tonal adjustment stage in the production chain, after you have balanced individual instruments. It is optimized for small, wide-bandwidth corrections that refine the overall mix rather than perform surgical cuts or boosts.
Its innovative filter design sets it apart from conventional equalizers. When you adjust adjacent bands, the response remains flat between those band edges. This approach preserves the relative harmonic balance of instruments while you shape the overall tonality, making it especially useful for mastering work that needs a transparent, smooth character.
Key Capabilities
The EQ provides 31 control bands spanning the audible range, increasing in one-third octave increments. A high pass filter and low pass filter with adjustable filter order extend its flexibility, alongside level trim and momentary bypass controls for comparing adjustments.
Its user interface allows you to click and drag to draw the EQ curve directly. By default, the display scale shows a moderate range, but if you boost a band beyond that, the scale expands to show larger changes. The processing engine derives from Harrison’s established DSP, originally developed for their digital consoles.
Workflow
You start by listening to the full mix and identifying broad tonal imbalances—too much low-mid mud, a slight dullness in the highs, or a need for overall air. Then, you click on the relevant band and drag to adjust, watching the curve for flat tops that ensure no unintended filter overlap.
Because the EQ is designed for mastering, you typically make adjustments in small, subtle steps. Use the bypass to check your changes against the original mix often. The level trim helps match output levels, and the high/low pass filters can gently clean up extreme frequencies without affecting the core sound.
Practical Applications
In practical use, the EQ suits final mix bus processing or dedicated mastering chains. It can correct a recessed upper range, tighten the low end, or add a subtle presence boost without disturbing the mix’s stereo image or depth.
The intuitive draw interface speeds up workflow compared to parameter-heavy EQs. Its flat-top behavior is particularly valuable when you need to apply a broad smiley-curve or a gentle shelf, ensuring that the mix’s harmonic relationships remain unchanged. This makes it a reliable tool for engineers who want a quick, precise way to shape final tone.
Key features
- 31 control bands with one-third octave spacing
- High pass and low pass filters with adjustable order
- Flat-top filter response preserves harmonic balance
- Level trim and momentary bypass controls
- Click-and-drag curve drawing interface
- Derived from Harrison’s XTools and digital console DSP
Best for
Mastering engineers and mixers who need a transparent, wide-bandwidth EQ for final tone shaping. Its flat-top filters and simple drawing interface make it ideal for subtle adjustments that preserve mix balance while polishing the overall sound.