Simple EQ

A free, open-source 3-band equalizer audio plugin with a real-time spectrum analyzer and response curve display, built using the JUCE framework.

The plugin is available as Windows VST3, macOS VST3, and macOS AU formats.

Features

• 3-Band Equalizer: Low, Mid, and High frequency bands with adjustable gain and Q controls.
• Spectrum Analyzer: Visualize the frequency spectrum of the incoming audio signal.
• Response Curve Display: Real-time graph of the filter response, aiding precise tonal adjustments.
• Low CPU Footprint: Efficient DSP implementation for smooth performance in any DAW.
• Precompiled Binaries: Ready-to-use plugin files included for Windows VST3, macOS VST3, and macOS AU.
• Open Source: Full source code available.

Repository

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Clone this fork:

git clone https://github.com/LarreaSound/SimpleEQ.git
cd SimpleEQ 

This repo contains:

SimpleEQ.jucer — the Projucer project file

SimpleEQ.filtergraph — DSP filter-graph definition

(On export) Build/ — your IDE project files and source code folders

Prerequisites

JUCE 6+ JUCE

A C++17-capable compiler (Visual Studio, Xcode, CLang, GCC)

Projucer (to open .jucer)

Building

Open SimpleEQ.jucer in Projucer

Set your desired plugin formats (e.g. VST3, AU) in the Project Settings → Exporters

Save and Export to generate IDE project files

Open the generated project in your IDE

Build the Plugin target

Usage

Load the built plugin in your DAW or audio host

Adjust Low, Mid, High bands (gain, frequency & Q)

Observe the Spectrum Analyzer and Response Curve updating in real time

Project Structure

SimpleEQ/

├── .gitignore

├── SimpleEQ.jucer # JUCE Projucer project

├── SimpleEQ.filtergraph # DSP filter-graph file

├── Builds/ # (auto-generated) IDE export folders

│ ├── VisualStudio2022/

│ ├── Xcode/

│ └── …

└── Source/ # (auto-generated) .cpp / .h plugin sources

Credits

Original Plugin & Tutorial by Matkat Music (PFM::SimpleEQ)

Recreated by Julio Larrea / LarreaSound (2025)