What is this?

REW MCP Server lets an LLM control Room EQ Wizard, analyze your measurements, and coach you through room treatment and speaker placement — step by step, one recommendation at a time.

Instead of staring at graphs, you get answers:

"You have a 12 dB null at 83 Hz caused by speaker boundary interference. Your monitors are 0.97 m from the rear wall — move them to 1.4 m or 0.6 m to shift the cancellation frequency out of the critical listening range. GLM cannot fix this; it's a physics problem."

Key capabilities

• Guided calibration — Mic gain staging, SPL calibration to 85 dB reference, L/R/Sub measurement sessions
• Plain language analysis — Room modes, SBIR, reflections, symmetry issues explained with causes and fixes
• GLM transparency — What Genelec's DSP corrected vs what it physically cannot
• Placement optimization — One change at a time, measure after each, validate the improvement
• 27 MCP tools — Full programmatic control of REW's API: measurements, signal generator, SPL meter, RTA, EQ, and more

Getting Started

Requirements

• Node.js 20+
• Room EQ Wizard running with API enabled (-api flag or Preferences)
• Measurement microphone (calibrated preferred — UMIK-1, UMIK-2, etc.)

Install

{
  "mcpServers": {
    "rew-mcp": {
      "command": "npx",
      "args": ["-y", "rew-mcp"]
    }
  }
}

claude mcp add rew-mcp -- npx -y rew-mcp

Or via Smithery:

npx -y @smithery/cli install rew-mcp --client claude

Example Workflow

You:    "Help me calibrate my studio monitors"

Claude: Connects to REW → checks your mic levels → calibrates to 85 dB SPL
        → measures Left, Right, Sub → analyzes the room → finds issues:

        1. 14 dB mode at 62 Hz (axial mode, fixable with bass trapping)
        2. 8 dB SBIR null at 120 Hz (move speakers 15 cm from rear wall)
        3. 3 dB L/R asymmetry above 2 kHz (side wall reflection)

        → guides you through fixes one at a time
        → re-measures after each change
        → validates improvement: "62 Hz peak reduced from 14 dB to 4 dB ✓"

Tools

Offline Analysis

REW API Control

Prompts & Resources

Claude Code Plugin

For Claude Code users, the included plugin adds guided workflows, domain knowledge, and quality automation on top of the MCP server.

# From a cloned repo
claude --plugin-dir ./plugin

# Or from npm (installs both the MCP server and plugin)
npm install -g rew-mcp
claude --plugin-dir $(npm root -g)/rew-mcp/plugin

Commands

Skills & Automation

See plugin/README.md for full details.

Documentation

Development

npm install          # Install dependencies
npm run build        # Build TypeScript
npm test             # Run tests (884 passing)
npm run test:coverage # With coverage report
npm run lint         # ESLint
npm run dev          # Watch mode

Contributing

Contributions welcome. See Contributing Guide and Code of Conduct.

git checkout -b feature/your-feature
npm test
git commit -m 'feat: add your feature'
git push origin feature/your-feature
# Open a Pull Request

License

MIT © Kolton Jacobs