IBS 70V Calculator MCP

Model Context Protocol (MCP) server for designing 70V/100V constant-voltage audio systems — sizing, amplifier recommendation, and cable loss calculation.

Built and maintained by IBS Áudio — Brazilian manufacturer of commercial audio equipment since 1979. Domain logic embedded; no external API calls; works offline.

What it does

Exposes three tools to any MCP-compatible client (Claude Desktop, Cursor, Cline, Continue, custom agents):

| Tool | Purpose | | --- | --- | | calculate_70v_system | Sizes a distributed audio system: total wattage, zones, SPL estimate, headroom, ABNT NBR 10152 compliance | | recommend_amplifier | Suggests the right IBS amplifier (PWM series) for the calculated load, including redundancy and multi-zone options | | calculate_cable_loss | Computes power loss in dB / %, voltage drop, and recommends a larger AWG if loss exceeds 0.5 dB |

All calculations follow:

• 70V/100V constant-voltage distribution (NEMA / IEC 60268-5)
• ABNT NBR 10152:2017 — Brazilian acoustic comfort standard
• AWG copper resistance @ 20°C (NIST / IEC 60228)
• NEC Article 760 — 25% headroom rule

Install

Global (recommended)

npm install -g ibs-70v-calculator-mcp

From source

git clone https://github.com/Austhen-Xcene/ibs-70v-calculator-mcp.git
cd ibs-70v-calculator-mcp
npm install
npm link

Run tests

npm test

Claude Desktop config

Add this entry to your claude_desktop_config.json:

macOS: ~/Library/Application Support/Claude/claude_desktop_config.json Windows: %APPDATA%\Claude\claude_desktop_config.json Linux: ~/.config/Claude/claude_desktop_config.json

{
  "mcpServers": {
    "ibs-70v-calculator": {
      "command": "npx",
      "args": ["-y", "ibs-70v-calculator-mcp"]
    }
  }
}

Or, if installed globally:

{
  "mcpServers": {
    "ibs-70v-calculator": {
      "command": "ibs-70v-calculator-mcp"
    }
  }
}

Restart Claude Desktop. Open a new conversation and type "Use the IBS 70V calculator to..." — the tools will appear automatically.

Examples

Example 1 — Restaurante 100 m² (background music)

"Tenho um restaurante de 100 m² com pé-direito de 3 m. Quero 8 alto-falantes de teto a 6 W cada para música ambiente. Calcule o sistema e sugira amplificador IBS."

The agent will call:

calculate_70v_system({
  area_m2: 100,
  num_speakers: 8,
  tap_watts: 6,
  environment_type: "restaurante"
})
// → 48 W de carga, 60 W com headroom, 1 zona, SPL ~76 dB @ ouvinte
// → ABNT NBR 10152: dentro da faixa de paging (75 dB)

recommend_amplifier({ total_wattage: 60 })
// → PWM120 (utilização 50%, folga térmica saudável)

Example 2 — Academia 200 m² (alta SPL para música motivacional)

"Academia 200 m² com 12 caixas de teto a 10 W cada. Cabo de 80 m do rack até o último falante. Que amplificador IBS usar e qual bitola de cabo?"

calculate_70v_system({
  area_m2: 200,
  num_speakers: 12,
  tap_watts: 10,
  environment_type: "academia"
})
// → 120 W de carga, 150 W com headroom, 2 zonas recomendadas
// → SPL ~82 dB (adequado para academia, NBR 10152 §5)

recommend_amplifier({ total_wattage: 150 })
// → PWM250 (utilização 60%)

calculate_cable_loss({ distance_m: 80, gauge: "16", wattage: 120 })
// → Perda 0.21 dB (~5%) — OK, dentro do aceitável

Example 3 — Supermercado 1.500 m² (paging + redundância)

"Supermercado de 1.500 m² com 60 alto-falantes a 15 W cada. Precisa redundância A/B para paging crítico. Linha mais longa: 250 m em cabo 14 AWG."

calculate_70v_system({
  area_m2: 1500,
  num_speakers: 60,
  tap_watts: 15,
  environment_type: "supermercado"
})
// → 900 W de carga, 1125 W com headroom, 10 zonas
// → SPL ~80 dB (paging adequado para supermercado)

recommend_amplifier({ total_wattage: 1125, prefer_redundancy: true })
// → Recomendação: PWM1250 (single)
// → Alternativa redundância: 2× PWM500 (carga 450 W cada, falha = -3 dB)

calculate_cable_loss({ distance_m: 250, gauge: "14", wattage: 900 })
// → Perda 0.42 dB (~9%) — OK, dentro do aceitável (<0.5 dB)

Reference — IBS Áudio amplifier catalog

| Model | Power | Channels | Typical use | | --- | --- | --- | --- | | PWM120 | 120 W | 1 | Salas pequenas, BGM | | PWM250 | 250 W | 1 | Lojas, restaurantes pequenos | | PWM500 | 500 W | 1 | Restaurantes médios, academias | | PWM1250 | 1250 W | 1 | Supermercados, indústrias | | PWM2500 | 2500 W | 1 | Grandes instalações, mall anchor | | PWM4x250 | 4×250 W | 4 | Multi-zona médio porte | | PWM4x500 | 4×500 W | 4 | Multi-zona grande |

Full datasheets: ibsaudio.com.br/categorias.html

Reference — ABNT NBR 10152:2017 levels

| Ambiente | NC máx (dB(A)) | BGM alvo | Paging alvo | | --- | --- | --- | --- | | Hospital (enfermaria) | 40 | 50 | 65 | | Escritório | 45 | 55 | 68 | | Restaurante | 50 | 65 | 75 | | Loja | 55 | 68 | 78 | | Igreja | 45 | 65 | 78 | | Hotel lobby | 50 | 62 | 72 | | Supermercado | 55 | 68 | 80 | | Academia | 60 | 80 | 85 | | Indústria leve | 65 | — | 88 |

Tool schemas

calculate_70v_system

| Parameter | Type | Required | Description | | --- | --- | --- | --- | | area_m2 | number | yes | Área em m² (1-100 000) | | num_speakers | integer | yes | Quantidade de alto-falantes (1-1000) | | tap_watts | number | yes | Tap por falante em W (0.25-60) | | environment_type | enum | no | Tipo de ambiente para checagem NBR 10152 |

recommend_amplifier

| Parameter | Type | Required | Description | | --- | --- | --- | --- | | total_wattage | number | yes | Carga total em W (já com headroom) | | prefer_redundancy | boolean | no | Sugerir configuração A+B |

calculate_cable_loss

| Parameter | Type | Required | Description | | --- | --- | --- | --- | | distance_m | number | yes | Comprimento one-way em metros | | gauge | enum | yes | AWG: 10, 12, 14, 16, 18, 20, 22 | | wattage | number | yes | Potência transportada em W |

Architecture

src/
├── index.js        # MCP server (stdio transport, tool routing)
└── calculator.js   # Pure domain functions, no I/O — 100% testable
test/
└── calculator.test.js  # node:test, no deps

Zero runtime dependencies beyond @modelcontextprotocol/sdk.

Contributing

Pull requests welcome — particularly for additional amplifier models, more environment presets from international standards (ANSI S12.2, ISO 7240), or improvements to SPL calculation (room acoustics, RT60).

git clone https://github.com/Austhen-Xcene/ibs-70v-calculator-mcp.git
cd ibs-70v-calculator-mcp
npm install
npm test

License

MIT © 2026 IBS Áudio / Austhen-Xcene

Disclaimer

This calculator provides engineering estimates suitable for system design and quoting. Final installation must be verified by a qualified audio engineer with site measurements. SPL calculations assume free-field conditions and do not account for room acoustics, reverberation, or speaker dispersion patterns. For voice evacuation (NFPA 72 / NBR 17240) systems, additional certification is required.