REW MCP Server

AI-powered room acoustics analysis for studio monitoring

A Model Context Protocol server that connects Claude to Room EQ Wizard, turning raw measurements into actionable acoustics guidance.

Getting Started · Tools · Plugin · Docs · Contributing

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 18+
• Room EQ Wizard running with API enabled (-api flag or Preferences)
• Measurement microphone (calibrated preferred — UMIK-1, UMIK-2, etc.)

Install

Claude Desktop

Add to claude_desktop_config.json:

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

Claude Code

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

Cursor

Or: Settings > Features > MCP Servers > npx -y rew-mcp

VS Code

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

| Tool | What it does | |------|-------------| | rew.analyze_room | Full-room analysis with prioritized, fixability-ranked recommendations | | rew.analyze_room_modes | Detect peaks, nulls, and correlate with theoretical room modes | | rew.analyze_decay | RT60, EDT, and ringing analysis (ISO 3382) | | rew.analyze_impulse | Early reflection detection and path estimation | | rew.compare_measurements | Before/after, L/R symmetry, multi-position comparison | | rew.compare_to_target | Score response against flat, Harman, REW room, or custom curves | | rew.interpret_with_glm_context | What GLM can fix vs what requires physical changes | | rew.average_measurements | Spatial averaging (RMS, vector, hybrid methods) | | rew.optimize_room | One-at-a-time placement optimization with validation | | rew.ingest_measurement | Parse REW text exports for offline analysis |

REW API Control

| Tool | What it does | |------|-------------| | rew.api_connect | Connect to REW's REST API | | rew.api_audio | Configure input/output devices and sample rate | | rew.api_check_levels | Verify mic gain (clipping/optimal/low zone feedback) | | rew.api_calibrate_spl | Semi-automated SPL calibration to target level | | rew.api_measure | Trigger sweeps, SPL readings, or configure measurement | | rew.api_measure_workflow | Orchestrated setup + level check + calibration + measurement | | rew.api_measurement_session | Stateful L/R/Sub measurement sequence | | rew.api_generator | Signal generator: pink noise, sweeps, tones | | rew.api_spl_meter | Live SPL metering (A/C/Z weighting, Slow/Fast/Impulse) | | rew.api_rta | Real-time analyzer control and capture | | rew.api_list_measurements | List loaded measurements | | rew.api_get_measurement | Fetch measurement data by UUID | | rew.api_import | Import measurement files into REW | | rew.api_measurement_commands | Execute per-measurement REW commands | | rew.api_measurement_eq | Manage per-measurement EQ, filters, and targets | | rew.api_eq | Global EQ defaults, house curves | | rew.api_groups | Measurement group management |

Prompts & Resources

| Prompt | Description | |--------|-------------| | rew_calibration_full | Complete end-to-end calibration workflow | | rew_gain_staging | Standalone mic gain and level calibration | | rew_measurement_workflow | Session-aware L/R/Sub measurement sequence | | rew_optimization_workflow | Iterative placement optimization loop |

| URI Template | Description | |--------------|-------------| | session://{session_id} | Session state, step, and captured measurements | | measurement://{measurement_id} | Stored frequency response data and metadata | | recommendations://{session_id} | Active optimization recommendations | | history://{session_id} | Measurement history and summaries |

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

| Command | Description | |---------|-------------| | /rew:calibrate | Full calibration workflow — levels, SPL, L/R/Sub, analysis, optimization | | /rew:analyze | Analyze measurements with prioritized recommendations | | /rew:optimize | Iterative placement optimization cycle | | /rew:status | Session state and next recommended step |

Skills & Automation

| Component | What it provides | |-----------|-----------------| | room-acoustics skill | Room modes, SBIR, treatment, GLM knowledge, target curves | | rew-workflows skill | Tool chaining patterns, workflow sequencing, best practices | | measurement-reviewer agent | Proactive data quality review after measurements | | workflow-enforcement hook | Soft-warns when tools are called out of recommended order |

See plugin/README.md for full details.

Documentation

| Document | Description | |----------|-------------| | Architecture | System design and data flow | | GLM Context | How Genelec GLM works and its limitations | | Analysis Rules | Detection algorithms and thresholds | | File Formats | REW export format specifications | | Resources | MCP resource URIs and payload shapes | | Examples | End-to-end measurement and analysis workflows |

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

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