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_{⭐ Featured / submitted on — full tracker →}

FreeEQ8 is a professional-grade EQ8 / EQ Eight inspired parametric equalizer, free and open-source 8-band parametric EQ plugin for macOS, Linux, and Windows. Linear phase, dynamic EQ, match EQ, per-band drive, band linking, M/S processing, oversampling, and a real-time spectrum analyzer — all in a single, zero-cost plugin. Built with JUCE for VST3 and AU.

ProEQ8 is one of the most advanced EQs available, competing directly with top tools like ZL EQ and TDR Nova.

Works with Reaper! Tested and built on Ableton 10+

🗂️ Release Vault — official monetized releases, distributed tracks, and catalog proof
🗂️ Release Vault Repo: https://github.com/GareBear99/TizWildin-Release-Vault

⬇️ Download Now — Free

FabFilter Pro-Q alternative for $0–$20

2min Demo ProEQ8 is included!

All releases →

🔊 Trademark Sound

BaisMaed — play / download Collab sound with - YUME/GR!EF

💫 Thanks to our supporters

📊 Current Status

Product	FreeEQ8 — free/open-source 8-band parametric EQ
Formats	VST3 · AU · Standalone
Platforms	macOS (universal) · Windows · Linux
Version	v2.3.0 (stable)
License	GPL-3.0

Tested in: Ableton Live 10+, REAPER, Logic Pro, FL Studio, Bitwig

Featured by: Rekkerd.org · AudioApp.cn · Midifan.com

Listed on: OpenAudio · awesome-music-production · Awesome Audio Dev List

📰 Press & Coverage

Outlet	Article
Rekkerd.org	FREE: FreeEQ8 parametric EQ effect plugin by Gary Doman
AudioApp.cn	福利：Gary Doman 推出 FreeEQ8 免费开源参量均衡器
Midifan.com	FreeEQ8 免费开源参量均衡器

📄 Publications

Title	Venue	Status
Real-Time State-Space Parameterization in Digital EQ	DAFx / AES	📝 Preprint

🏫 DAFx26 Demo Track (MIT, September 2026) — Submitted May 29, 2026 (#109)

🎁 TizWildin Hub

Tracking our first 1,200 users — at 1,000 we'll run giveaways (ProEQ8 keys, sample packs, early access).

Full submission tracker: docs/FEATURED_ON.md · docs/SUBMISSIONS_2026.md

FreeEQ8 in Ableton Live

🆚 How FreeEQ8 Compares

Feature	FreeEQ8	FabFilter Pro-Q 4	ZL Equalizer 2	TDR Nova
Price	Free	$199	Free	Free
Open Source	GPL-3.0	—	AGPL-3.0	—
Bands	8	24	24	4 + HP/LP
Dynamic EQ	✓ (thresh / ratio / atk / rel)	✓	✓	✓
Linear Phase	✓	✓	✓	—
Match EQ	✓	✓	✓ (WIP)	—
Mid/Side	✓ (per-band)	✓	✓	— (free)
Per-Band Drive	✓ (tanh saturation)	—	—	—
Band Linking	✓ (groups A/B)	—	—	—
Oversampling	✓ (1×–8×)	internal	—	—
Adaptive Q	✓	—	—	—
Spectrum Analyzer	✓ (4096-pt FFT)	✓	✓	✓
Level Meter	✓ (peak + RMS)	—	—	—
Undo / Redo	✓	✓	✓	—
Collision Detection	✓ (Pro)	✓	✓	—
Surround / Atmos	—	✓	—	—
Formats	VST3, AU	VST3, AU, AAX, CLAP	VST3, AU, LV2	VST3, AU, AAX

FreeEQ8 is the only free EQ that combines linear phase + dynamic EQ + match EQ + per-band saturation + band linking in one plugin.

⚡ ProEQ8 — Available Now ($20)

Love FreeEQ8? ProEQ8 takes everything further.

ProEQ8 is the commercial big brother of FreeEQ8 — same rock-solid DSP engine, massively expanded. Included in the latest release download.

	FreeEQ8 (Free)	ProEQ8 ($20)
Bands	8	24
Saturation Modes	tanh	Tube · Tape · Transistor · Tanh
A/B Comparison	—	✓ (instant snapshot toggle)
Auto-Gain Bypass	—	✓ (RMS-matched)
Piano Roll Overlay	—	✓ (note frequency reference)
Collision Detection	—	✓ (overlapping band warnings)
Factory Presets	30	30+ (genre-specific)
Dynamic EQ	✓	✓
Linear Phase	✓	✓
Match EQ	✓	✓
Mid/Side	✓	✓
Oversampling	✓	✓
Band Linking	✓	✓
Formats	VST3, AU	VST3, AU

ProEQ8 is included in the macOS DMG download. A license key is required to unlock it — purchase through the link above to receive your key via email. Without a license, ProEQ8 runs in demo mode: 2 minutes of clean playback, then a 30-second mute window (repeats).

🧠 Smart EQ Layer (shipped v2.2.3–2.2.4)

FreeEQ8 includes a real-time decision layer on top of the existing 8-band engine — not to replace surgical control, but to make getting to a clean mix faster than most paid EQs.

Shipped:

• Source/DSP/ResonanceDetector.h — log-frequency peak finder that produces up to 4 ranked suggestion bands with recommended frequency, cut-gain, Q, confidence score, and a semantic label ("mud", "boxiness", "harshness", "sibilance" …).
• Source/DSP/IntentMode.h — behavioural biasing: None / Vocal Clean / Drum Punch / Guitar Space / Master Polish. Each mode shifts the detector’s scoring curve toward the frequency zones that matter for that source, without forcing preset bands.
• Source/DSP/FrequencyExplainer.h — static frequency → semantic description map powering the Explain-on-hover UX (“Cutting mud (320 Hz)” / “Adding air (12 kHz)”).
• intent_mode APVTS parameter — host-automatable, wired to editor dropdown.
• Glowing suggestion-node overlay on the response curve (amber rings, confidence-scaled opacity).
• One-click “apply suggestion” — drops a detected peak into the next unused band via APVTS (undo-able).
• Explain-on-hover popup when mousing over any band or suggestion node.
• Pre-ring warning overlay when DrumPunch + Linear Phase are active simultaneously.
• Deterministic, allocation-free, UI-thread safe — piggybacks on the existing triple-buffered SpectrumFIFO.

Coming next:

• Zero-Lag auto-switch between linear-phase (precision) and minimum-phase (real-time)

No other free open-source 8-band EQ currently combines intent-aware resonance detection + explain-on-hover + one-click apply. See docs/SMART_EQ_LAYER.md for the full algorithm and status matrix.

🔍 Code Audit

A full line-by-line audit of the DSP, threading, and restriction system is published at AUDIT.md. Summary: FreeEQ8 has zero feature locks and zero nag interruptions during real-time playback. Offline export is limited to 4 minutes 30 seconds (ProEQ8 removes this limit). All bug fixes through v2.2.5 are documented with root cause analysis.

📊 Benchmarks & RT-safety

FreeEQ8 / ProEQ8 v2.2.5 ships with a proven real-time-safe DSP engine:

• Zero heap allocation on the audio thread for any user action (pooled oversamplers).
• Canonical swap-chain triple-buffer for both the spectrum FIFO and the linear-phase FIR kernel — verified under concurrent stress (3 runs × 400 ms, ~600 M samples, 0 tears).
• Linear-phase FIR rebuild on a dedicated juce::Thread — no FFT work on the audio thread.
• MatchEQ chunking handles DAW blocks of any size (previously dropped on n > fftSize).

Full evidence and numbers:

• Milestone A report — math, benchmarks, stress-test results, sonic-impact analysis.
• v2.2.0 release readiness — what's verified green/yellow/red.
• Tests/AuditBench.cpp — reproducible micro-benchmarks (clang -O3 -DNDEBUG -pthread).
• Tests/AuditRegressionTest.cpp — concurrent-stress invariants for the triple-buffer + chunking patterns.

✨ Features

Core EQ

• 8 Independent Bands — full parametric control (frequency, Q, gain)
• 6 Filter Types per band: Bell, Low Shelf, High Shelf, High Pass, Low Pass, Bandpass
• Multiple Slopes — 12 / 24 / 48 dB/oct via cascaded biquad stages
• Per-Band Enable/Disable & Solo for A/B comparison and audition
• Parameter Smoothing (20ms linear interpolation, coefficients refreshed every 16 samples during parameter automation; every sample when Dynamic EQ is active)

Advanced Processing

• Linear Phase Mode — symmetric FIR from combined biquad magnitude, overlap-add FFT convolution (2048-sample latency when active)
• Dynamic EQ — per-band envelope follower with sidechain bandpass, threshold, ratio, attack & release
• Per-Band Saturation / Drive — gain-compensated tanh waveshaper (0–100%)
• Mid/Side Processing — M/S encode/decode with per-band channel routing (Both / L-Mid / R-Side)
• Oversampling — 1x / 2x / 4x / 8x using JUCE polyphase IIR half-band filters
• Band Linking — link groups A/B propagate frequency (ratio), gain & Q (delta) changes
• Match EQ — capture a reference spectrum, analyze current signal, compute & apply per-bin correction via FFT
• Adaptive Q — automatically widens Q with increasing gain

Visualization & UI

• Real-Time Spectrum Analyzer — 4096-point FFT, Hann window, pre/post EQ toggle
• Interactive Response Curve — composite + per-band colored curves with dB/frequency grid
• Draggable Band Nodes — click-drag for freq/gain, shift+drag for Q, right-click context menu
• Stereo Level Meter — peak hold + RMS display
• Selected-Band Paradigm — 8 colored band buttons, single set of controls rebound per selection
• Dark Theme — resizable UI (750×550 to 1400×900)

Global Controls

• Output Gain (-24 dB to +24 dB)
• Scale (0.1x to 2x) — scales all band gains simultaneously
• Preset System — save / load / delete, 30 factory presets
• Undo / Redo — integrated with JUCE UndoManager via APVTS
• State Save/Restore — all settings persist in your DAW project

DSP Specifications

• Stereo processing (or Mid/Side)
• Sample rates: 44.1 kHz to 192 kHz+
• Dual filter topology: RBJ TDF-II biquad (FreeEQ8) + Simper SVF via trapezoidal integration (ProEQ8) — modulation-stable Dynamic EQ
• Double-precision (64-bit) internal arithmetic, float I/O
• Zero latency in minimum-phase mode; linear phase adds 2048 samples
• 0.62% single-core CPU budget at 44.1 kHz (SVF 8-band stereo, 161× headroom)
• Low CPU usage (disable unused bands, lower oversampling to reduce load)

Compatibility

• macOS: 10.13 High Sierra and later (universal binary: Intel + Apple Silicon)
• Linux: Debian/Ubuntu 20.04+ (VST3 only; see build instructions for dependencies)
• Windows: 10 and later (64-bit)
• DAWs tested: Ableton Live 10+, Logic Pro, FL Studio, Bitwig, REAPER
• Formats: VST3, AU (macOS), Standalone (all platforms)

🚀 Quick Start

macOS

git clone --recursive https://github.com/GareBear99/FreeEQ8.git
cd FreeEQ8
./build_macos.sh

Linux (Debian/Ubuntu)

git clone --recursive https://github.com/GareBear99/FreeEQ8.git
cd FreeEQ8
./build_linux.sh          # installs deps via apt, then builds

Windows

git clone --recursive https://github.com/GareBear99/FreeEQ8.git
cd FreeEQ8
.\build_windows.ps1

Plugins will be automatically installed to your system plugin directories.

📋 Build Instructions

Prerequisites

macOS

• Xcode Command Line Tools: xcode-select --install
• CMake 3.15+: brew install cmake

Linux (Debian/Ubuntu)

• GCC 9+ or Clang 10+
• CMake 3.15+
• JUCE system dependencies (installed automatically by build_linux.sh): libasound2-dev libjack-jackd2-dev libfreetype6-dev libx11-dev libxcomposite-dev libxcursor-dev libxext-dev libxfixes-dev libxinerama-dev libxrandr-dev libxrender-dev libwebkit2gtk-4.0-dev

Windows

• Visual Studio 2019+ with C++ build tools
• CMake 3.15+

Detailed Build Steps

1. Clone with JUCE Submodule

git clone --recursive https://github.com/GareBear99/FreeEQ8.git
cd FreeEQ8

If you already cloned without --recursive:

git submodule update --init --recursive
cd JUCE && git checkout 7.0.12 && cd ..

2. Build

macOS:

chmod +x build_macos.sh
./build_macos.sh

Linux:

chmod +x build_linux.sh
./build_linux.sh

Windows:

.\build_windows.ps1

3. Plugin Installation

macOS (automatic):

• VST3: ~/Library/Audio/Plug-Ins/VST3/FreeEQ8.vst3
• AU: ~/Library/Audio/Plug-Ins/Components/FreeEQ8.component

Linux (manual):

• Copy build/FreeEQ8_artefacts/Release/VST3/FreeEQ8.vst3 to ~/.vst3/

Windows (manual):

• Copy build\FreeEQ8_artefacts\Release\VST3\FreeEQ8.vst3 to:
  • C:\Program Files\Common Files\VST3\

4. Rescan in Your DAW

• Ableton Live: Preferences → Plug-ins → Rescan
• Logic Pro: Automatic detection
• FL Studio: Options → Manage plugins → Find plugins

🎛️ Usage Guide

Parameter Ranges

Parameter	Range	Scale	Description
Frequency	20 Hz – 20 kHz	Logarithmic	Center/cutoff frequency
Q	0.1 – 24	Logarithmic	Bandwidth (0.1 = wide, 24 = narrow)
Gain	-24 dB to +24 dB	Linear	Boost/cut amount
Slope	12 / 24 / 48 dB/oct	Discrete	Filter steepness (1/2/4 cascaded stages)
Drive	0 – 100 %	Linear	Per-band tanh saturation amount
Channel	Both / L-Mid / R-Side	Discrete	Per-band channel routing
Link Group	-- / A / B	Discrete	Band linking group
Dyn Threshold	-60 dB to 0 dB	Linear	Dynamic EQ threshold
Dyn Ratio	1:1 – 20:1	Logarithmic	Dynamic EQ compression ratio
Dyn Attack	0.1 – 100 ms	Logarithmic	Dynamic EQ attack time
Dyn Release	1 – 1000 ms	Logarithmic	Dynamic EQ release time
Output	-24 dB to +24 dB	Linear	Master output level
Scale	0.1x – 2x	Linear	Global gain multiplier

Common EQ Techniques

Surgical EQ (Problem Frequency Removal)

Band: Bell filter
Q: 6-12 (narrow)
Gain: -6 to -12 dB

Musical EQ (Broad Tonal Shaping)

Band: Bell/Shelf filter
Q: 0.5-2 (wide)
Gain: ±3 to ±6 dB

High-Pass Filtering

Band: HighPass filter
Freq: 20-120 Hz (depends on source)
Q: 0.7 (standard)

Example Settings

Kick Drum:

• Band 1: Bell @ 60Hz, Q=1.5, +4dB (sub thump)
• Band 2: Bell @ 200Hz, Q=3, -3dB (cardboard removal)
• Band 3: Bell @ 3kHz, Q=2, +2dB (beater click)

Acoustic Guitar:

• Band 1: HighPass @ 80Hz (rumble removal)
• Band 2: Bell @ 200Hz, Q=1.5, -2dB (boominess)
• Band 3: Bell @ 3kHz, Q=1, +3dB (presence)
• Band 4: HighShelf @ 8kHz, +2dB (air)

Vocals:

• Band 1: HighPass @ 80Hz (rumble)
• Band 2: Bell @ 250Hz, Q=2, -3dB (muddiness)
• Band 3: Bell @ 1kHz, Q=1, +2dB (body)
• Band 4: Bell @ 5kHz, Q=2, +3dB (clarity)

🔧 Technical Details

Architecture

┌──────────────────────────────────────────────────────┐
│               FreeEQ8 Audio Processor                │
├──────────────────────────────────────────────────────┤
│  Input Buffer (Stereo)                               │
│          ↓                                           │
│  Spectrum FIFO (pre-EQ) ──→ UI spectrum display      │
│          ↓                                           │
│  ┌─── IF linear_phase ───┐  ┌── ELSE (min-phase) ──┐│
│  │ Build composite mag   │  │ Oversampling ↑ (opt.) ││
│  │ response from biquads │  │       ↓               ││
│  │       ↓               │  │ M/S Encode (optional) ││
│  │ FIR convolution       │  │       ↓               ││
│  │ (overlap-add FFT,     │  │ Per-band loop ×8:     ││
│  │  4096-tap, 8192 FFT,  │  │  ├ Dyn EQ envelope    ││
│  │  2048-sample latency) │  │  ├ Smooth + update    ││
│  │       ↓               │  │  │  coefficients      ││
│  │ Output Gain           │  │  ├ Cascaded biquads   ││
│  └───────────────────────┘  │  │  (1/2/4 stages)    ││
│                              │  └ Drive (tanh)       ││
│                              │       ↓               ││
│                              │ Output Gain & Scale   ││
│                              │       ↓               ││
│                              │ M/S Decode (optional) ││
│                              │       ↓               ││
│                              │ Oversampling ↓ (opt.) ││
│                              └───────────────────────┘│
│          ↓                                           │
│  Match EQ correction (FFT overlap-add, optional)     │
│          ↓                                           │
│  Spectrum FIFO (post-EQ) ──→ UI spectrum display     │
│          ↓                                           │
│  Output Metering (peak hold + RMS)                   │
│          ↓                                           │
│  Output Buffer (Stereo)                              │
└──────────────────────────────────────────────────────┘

DSP Implementation

• Filter Structure: Transposed Direct Form II biquad (Biquad.h) + Simper SVF (SvfBiquad.h) with tan() pre-warp
• Coefficient Calculation: RBJ Audio EQ Cookbook (FreeEQ8) / Cytomic SVF (ProEQ8)
• Smoothing: Linear interpolation over 20ms
• Update Rate: Coefficients refreshed every sample when Dynamic EQ is active; every 16 samples during parameter smoothing (amortised cost). Variable-cadence engine (v2.2.3) batches to 4-sample intervals during stable envelopes.
• Precision: Double-precision (64-bit) coefficients and internal state; float I/O
• Linear Phase: 4096-tap symmetric FIR, 8192-point FFT, overlap-add convolution
• Dynamic EQ: One-pole envelope follower with sidechain bandpass at band frequency
• Spectrum: 4096-point FFT, Hann window, lock-free SPSC FIFO
• SIMD Scaffold: SvfBandArray<8> with AVX2/SSE2/Neon dispatch (v2.2.4)

Project Structure

FreeEQ8/
├── Source/
│   ├── PluginProcessor.h/.cpp     # Main audio processor
│   ├── PluginEditor.h/.cpp        # UI editor & layout
│   ├── Config.h                   # Product config (FreeEQ8 vs ProEQ8)
│   ├── DSP/
│   │   ├── Biquad.h               # RBJ biquad filter (FreeEQ8 path)
│   │   ├── SvfBiquad.h            # Simper SVF filter (ProEQ8 path)
│   │   ├── SvfBandArray.h         # SIMD-vectorised SVF (AVX2/SSE2/Neon)
│   │   ├── EQBand.h               # EQ band with smoothing, drive & dynamic EQ
│   │   ├── SpectrumFIFO.h         # Lock-free SPSC triple-buffer FFT FIFO
│   │   ├── LinearPhaseEngine.h    # FIR-based linear-phase EQ engine
│   │   ├── NaturalPhaseEngine.h   # 256-tap natural-phase mode
│   │   ├── MatchEQ.h              # Reference capture & correction curve
│   │   ├── ResonanceDetector.h    # Allocation-free resonance peak finder
│   │   ├── IntentMode.h           # Vocal/Drum/Guitar/Master weighting
│   │   └── FrequencyExplainer.h   # Semantic frequency → label map
│   ├── UI/
│   │   ├── ResponseCurveComponent.h/.cpp  # EQ curve + spectrum + nodes
│   │   └── LevelMeter.h           # Stereo peak/RMS level meter
│   ├── Presets/
│   │   └── PresetManager.h/.cpp   # Preset save/load system
│   ├── UpdateChecker.h            # GitHub releases update checker
│   └── LicenseValidator.h         # License + demo + export limit
├── Tests/
│   ├── BiquadTest.cpp             # RBJ coefficient correctness
│   ├── SvfTest.cpp                # SVF correctness (11 assertions)
│   ├── AuditRegressionTest.cpp    # Triple-buffer + chunking stress tests
│   └── AuditBench.cpp             # RT-safety micro-benchmarks
├── server/
│   ├── stripe-webhook.js          # Cloudflare Worker for Stripe → license
│   ├── wrangler.toml              # Wrangler deployment config
│   └── package.json               # Server dependencies (wrangler)
├── PAPER.md                       # Technical paper (DAFx/AES submission)
├── BENCHMARK.md                   # Full benchmark results & methodology
├── AUDIT.md                       # Line-by-line code audit report
├── ROADMAP_2_5_PLUS.md            # Long-horizon roadmap through v2.3.0
├── STRIPE_SETUP.md                # ProEQ8 Stripe deployment guide
├── FeatureBench.cpp               # Standalone benchmark suite (no JUCE)
├── CMakeLists.txt                 # CMake config (FreeEQ8 + ProEQ8 targets)
├── docs/                          # Screenshots & assets
├── JUCE/                          # JUCE framework (submodule)
└── build/                         # Build output (ignored)

🛣️ Roadmap

v0.4.0

• Real-time spectrum analyzer
• Interactive frequency response curve display
• Draggable band nodes on curve
• Adaptive Q implementation
• Band solo/audition mode
• Preset management system

v0.5.0

• Multiple filter slopes (12/24/48 dB/oct) via cascaded biquads
• Mid/Side processing mode with M/S encode/decode
• Per-band channel routing (Both / L-Mid / R-Side)
• Oversampling options (1x, 2x, 4x, 8x)
• Output metering with peak hold and RMS
• Resizable UI (700×500 to 1400×900)

v1.0.0

• Linear phase mode (FIR convolution via overlap-add FFT)
• Dynamic EQ capabilities (per-band envelope follower with threshold/ratio/attack/release)
• Band linking (link groups A/B with delta-based freq/gain/Q propagation)
• Per-band saturation/drive (gain-compensated tanh waveshaper)
• Undo/Redo system (integrated with APVTS UndoManager)
• Match EQ functionality (capture reference spectrum, compute & apply correction)

v2.0.0

• Online license activation (2 devices per key) with Stripe checkout
• ProEQ8 commercial target (24 bands, 4 saturation modes, A/B, auto-gain)
• Cloudflare Worker license server + Resend email delivery
• Demo mode for unactivated ProEQ8 (2 min clean + 30 s mute cycle)

v2.1.0

• Standalone app included in all platform packages
• Hardened ProEQ8 license: device-bound activation, 7-day re-verify, 30-day offline grace
• Server /verify endpoint for periodic re-validation
• Obfuscated signing secret in binary
• Fixed JUCE 7.0.12 API compatibility

v2.2.0

• Real-time safety: zero heap allocation on the audio thread for any user action (Milestone A / A1)
• SpectrumFIFO + LinearPhaseEngine kernel on canonical swap-chain triple-buffer (A4 / A5)
• Linear-phase FIR rebuild moved to a dedicated juce::Thread worker (A5)
• MatchEQ::applyCorrection handles arbitrarily large DAW blocks instead of silent early-return (A3)
• Editor modal dialogs + license HTTP callbacks are lifetime-safe via juce::WeakReference (A2)
• Demo cadence: 2 minutes of clean playback + 30-second mute window
• getTailLengthSeconds reports the MatchEQ overlap-add tail for offline renders (A7)

v2.2.1–2.2.2

• Transistor saturation gain bug fixed (ProEQ8)
• Dynamic EQ zero-lag coefficient update when dynEnabled
• MatchEQ correctionGain[] precompute (3× throughput improvement)
• Simper SVF engine (SvfBiquad.h) — modulation-stable SVF, trapezoidal integration

v2.2.3–2.2.4

• Variable-cadence Dynamic EQ (75% CPU savings on sustained signals)
• intent_mode APVTS parameter + editor dropdown
• ResonanceDetector wired to UI timer at 30 Hz
• Suggestion overlay (glowing amber nodes on response curve)
• One-click “apply suggestion” into next unused band
• Explain-on-hover popup on band + suggestion nodes
• Compact / mini-window mode (identical coordinate mapping)
• Pre-ring warning overlay (DrumPunch + Linear Phase)
• Oversampling crossfade buffer (128-sample, eliminates pop)
• SvfBandArray SIMD scaffold (AVX2/SSE2/Neon)
• NaturalPhaseEngine (256-tap, 128-sample latency)
• pluginval CI (strictness-level 10)

v2.2.5

• Transistor saturation invD*d no-op bug fixed in shipped code
• MatchEQ hot-path pow() eliminated — correctionGain[] precompute
• SvfTest.cpp correctness suite (11 assertions, all passing)
• FreeEQ8 export limit (4:30 offline render)
• Version consistency across all docs (no fake v2.4/v2.5/v3.0 refs)
• PAPER.md section numbering fixed (§6 Benchmarks, §8 Compact View, §9 Future Work)

v2.3.0 (Current Release) — Stable Release

• Version alignment (CMakeLists.txt + Config.h both 2.3.0)
• Get Pro button for FreeEQ8 (opens ProEQ8 checkout)
• Full codebase audit completed
• Smart EQ layer documentation expanded in PAPER.md
• CI/CD fixes (Linux webkit2gtk-4.1, Windows MSVC lambda capture, macOS retry)
• Build verified (AU, VST3, Standalone) on all platforms

v2.4.0 (Planned) — ProEQ8 Launch

• SVF wired into EQBand via #if PROEQ8
• 24-band layout
• Zero-Lag auto-switch between linear-phase and minimum-phase modes
• Stripe checkout live
• Cross-instance ARC-Core spine

🤝 Contributing

Contributions are welcome! Here's how you can help:

1. Fork the repository
2. Create a feature branch: git checkout -b feature/amazing-feature
3. Commit your changes: git commit -m 'Add amazing feature'
4. Push to the branch: git push origin feature/amazing-feature
5. Open a Pull Request

Development Guidelines

• Follow existing code style
• Add comments for complex DSP algorithms
• Test on both macOS and Windows if possible
• Update documentation for new features

Areas for Contribution

• 🎨 UI/UX improvements
• 🔊 Additional filter types
• 🐛 Bug fixes and optimizations
• 📚 Documentation improvements
• 🧪 Unit tests

📝 Changelog

See CHANGELOG.md for the full version history with detailed per-file changes.

📄 License

This project is licensed under the GNU General Public License v3.0 - see the LICENSE file for details.

Note: JUCE has its own licensing requirements. For commercial use, you may need a JUCE license. See JUCE Licensing for details.

⚠️ Legal Notice

FreeEQ8 is an original implementation of a parametric EQ plugin. It is:

• NOT affiliated with, endorsed by, or derived from Ableton AG
• NOT a clone of Ableton's EQ Eight
• An independent, open-source project
• Built using public-domain DSP algorithms (RBJ Audio EQ Cookbook)

📊 Benchmarks

Every feature claim is backed by a reproducible standalone benchmark suite. All features pass at >10x CPU headroom at 44.1 kHz / 512-sample blocks.

Key numbers (g++ -O3, x86-64, median of 16 trials):

Feature	ns/sample	Headroom
Single biquad band (Bell)	5.1	>2200x
8-band stereo full path	41.5	>273x
Dynamic EQ (per-sample, zero-lag)	68.3	>166x
Linear phase FIR rebuild	36.5 µs/event	background thread
Match EQ correction (v2.2.1)	2.8	>4000x
Match EQ correction (old naive pow)	7.4	1527x
Mid/Side encode+decode	0.42	>27,000x
SpectrumFIFO push (audio thread)	0.66	>17,000x
Oversampling 8x EQ cost	213	>53x
Tanh saturation (stereo)	61.4	>184x

→ Full results and methodology: BENCHMARK.md

Build and run the benchmarks yourself (no JUCE required):

g++ -std=c++17 -O3 -DNDEBUG -pthread Tests/FeatureBench.cpp -o FeatureBench -I.
./FeatureBench

🐛 Known Issues

• Changing oversampling mid-playback may cause a brief click (IIR half-band filter state differs between orders; reset on switch)
• Linear phase mode adds 2048 samples of latency (reported to the DAW via setLatencySamples)
• Match EQ capture is mono-summed; correction is applied per-channel
• Linear phase mode does not apply M/S, per-band drive, or dynamic EQ — those features require per-sample biquad state and are on the minimum-phase path only. The oversampling selector and the affected controls are greyed out in the UI when linear phase is active

Fixed in v2.2.1:

• Transistor saturation gain error (ProEQ8) — double-multiply bug caused ~d× level at high drive; fixed
• Dynamic EQ coefficient lag — up to 16-sample transient lag between envelope detection and filter response; now zero-lag when Dynamic EQ is enabled
• Linear phase + oversampling undocumented interaction — behaviour now explicitly documented in source

Report issues at: https://github.com/GareBear99/FreeEQ8/issues

💡 Tips & Tricks

Performance Optimization

• Disable unused bands to reduce CPU load
• Use wider Q values (lower numbers) for smoother processing
• Enable adaptive Q for automatic gain-dependent Q adjustment

Mixing Workflow

1. Start with subtractive EQ (cut problem frequencies)
2. Use narrow Q to identify resonances
3. Use wide Q for musical boosts
4. Check your EQ in mono to avoid phase issues

Sound Design

• Stack multiple bell filters at the same frequency with different Q values
• Automate the scale parameter for dramatic filter sweeps
• Use extreme Q values (>10) for creative resonances

🙏 Acknowledgments

• JUCE Framework - Cross-platform audio plugin framework
• Robert Bristow-Johnson - RBJ Audio EQ Cookbook
• Audio Plugin Development Community - For knowledge sharing
• Ableton - For inspiration (not affiliation)

💖 Support the Project

FreeEQ8 is free and open source. If it's useful to you, consider supporting development:

Other ways to help:

• ⭐ Star this repo — helps others find FreeEQ8
• 🐛 Report bugs — open an issue
• 🔀 Contribute — PRs are welcome
• 📣 Spread the word — tell a producer friend

📧 Contact

• Issues: GitHub Issues
• Discussions: GitHub Discussions
• Email: neovectr.inc@gmail.com

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Built with ❤️ by Gary Doman (GareBear99/TizWildin)

"Great sound shouldn't cost anything"

TizWildin FREE sample packs

Pack	Description
TizWildin-Aurora	3-segment original synth melody pack with loops, stems, demo renders, and neon/cinematic phrasing
TizWildin-Obsidian	Dark cinematic sample pack with choir textures, menu loops, transitions, bass, atmosphere, drums, and electric-banjo extensions
TizWildin-Skyline	30 BPM-tagged synthwave and darkwave loops with generator snapshot and dark neon additions
TizWildin-Chroma	Multi-segment game synthwave loop sample pack from TizWildin Entertainment
TizWildin-Chime	Multi-part 88 BPM chime collection spanning glass, void, halo, reed, and neon synthwave lanes
Free Violin Synth Sample Kit	Physical-model violin sample kit rendered from the Instrudio violin instrument
Free Dark Piano Sound Kit	88 piano notes + dark/cinematic loops and MIDI
Free 808 Producer Kit	94 hand-crafted 808 bass samples tuned to every chromatic key
Free Riser Producer Kit	115+ risers and 63 downlifters - noise, synth, drum, FX, cinematic
Phonk Producer Toolkit	Drift phonk starter kit - 808s, cowbells, drums, MIDI, templates
Free Future Bass Producer Kit	Loops, fills, drums, bass, synths, pads, and FX

Related audio projects

• VF-PlexLab - VocalForge PersonaPlex Lab starter repo for a JUCE plugin + local backend + HTML tester around NVIDIA PersonaPlex.
• PAP-Forge-Audio - Procedural Autonomous Plugins runtime for generating, branching, validating, and restoring plugin projects from natural-language sound intent.

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Tester Call

FreeEQ8 is looking for real-world DAW testers.

Please test the latest release in your DAW and report compatibility feedback here:

https://github.com/GareBear99/FreeEQ8/issues/new?template=tester-feedback.yml

Helpful feedback includes OS, DAW, plugin format, what worked, what broke, and steps to reproduce.

See the full tester call:

https://github.com/GareBear99/FreeEQ8/blob/main/docs/testing/TESTER_CALL.md