Diamond Color EQ 4

Name: Diamond Color EQ 4
Price: 112.41 USD
Author: Acustica Audio

by Acustica Audio · EQ · Mastering color EQ

Not rated yet

Diamond Color EQ 4 is a mixing and mastering EQ developed with Luca Pretolesi and Studio DMI, with four broad overlapping bands and a sampled analog preamp stage.

It adds mid-side control and a FOCUS X2 mode for mastering, and costs €99 (about $112.41) on sale, regularly €199.

Best for: Mastering, Mix Bus, Vocals, Drums, Bass. Genres: Electronic & EDM, Pop, Hip-Hop & Trap.

Keywords: mastering, full mix, mid/side, mixing, analog-sounding, broad-strokes, musical, wide, bass, beginner-friendly, bus processing, drums, mix bus, organic, smooth, static, surgical, vocals.

What it does

Diamond Color EQ 4 is the fourth version of Acustica Audio's color EQ, made with mastering engineer Luca Pretolesi of Studio DMI in Las Vegas. Its idea, in Pretolesi's words: "The Color EQ fills the gaps between frequencies."

Four musical bands: overlapping bands about two octaves wide, with smooth, continuous curves that suit automation.
Cut filters: precision high-pass and low-pass filters for cleaning up the extremes.
PRE stage: a sampled analog preamp built with Acustica's NOVA hybrid technology, for added weight and color.
Stereo control: L/R and mid-side processing, with dedicated listening modes for each channel.
FOCUS X2: a tool for finer detail work when mastering.
Two views: Standard and Extended, the latter with spectrum feedback.

Pretolesi has mixed and mastered for Diplo, Major Lazer and Steve Aoki, and the developer says the plugin turns his approach into "a repeatable workflow". Version 4 works at 44.1 to 96 kHz. The store showed a sale price when checked. Owners of an earlier Color EQ or a NOVA-powered plugin get upgrade offers. The product page does not mention a demo.

Source: Acustica Audio product page

When to use it

Diamond Color EQ 4 is built around wide, gentle bands and sampled analog tone, tuned by a working mastering engineer, so it rewards big, musical moves on full mixes and stems. Among the rated EQs it is closest in spirit to Mäag Audio EQ4: a few broad bands for adding sheen and weight rather than fixing problems. It is less suited to corrective work than Pro-Q 4, the precise, clean mastering standard, or Kirchhoff-EQ, a modern clean EQ with many filter shapes, and its four bands give less control than a parametric EQ.

Best for: broad tonal moves and analog color on masters, mix buses and stems.
Genres: EDM, pop and hip-hop, where Studio DMI does much of its work, and any modern mix.
Look elsewhere if: you need narrow surgical cuts or dynamic EQ (Pro-Q 4 or TDR Nova), or a free broad-strokes tone EQ (TDR VOS SlickEQ).
Tip: a review of the original version found it strongest on buses and full mixes, with the preamp best kept for single tracks.

What producers say

The original Diamond Color EQ was very well received; no reviews of version 4 were found yet.

DJBooth (2017, original version) gave it 10/10 and called it "hands down the best sounding plugin EQ ever made", praising natural-sounding high boosts and low bands that keep power without boxiness.
Usage note: the same review suggested it suits experienced users, and that beginners should learn a surgical digital EQ first.
Criticisms: the gain knobs needed very fine adjustment, and the original had a fixed mid-band frequency.

DJBooth review (original version)

Where to buy

Acustica Audio: $112.41 (regular $225.96) (€99 (regular €199) converted to USD (ECB rate, 29 Sep 2026))

Tutorials and reviews

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