# Audio Calc – Room Mode Frequencies

> Audio Calc – Room Mode Frequencies is a paid API for AI agents from audio-calc.x402tookit.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-29).

Calculates axial, tangential, and oblique room mode frequencies for a rectangular room, plus the Schroeder frequency derived from RT60.

## Facts

- Endpoint: GET https://audio-calc.x402tookit.com/room-modes?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/audio-calc-room-mode-frequencies-d31b4b21
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_7tqdAlom_HSU1Q8FDGgFe

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability audio-calc-room-mode-frequencies-d31b4b21
```

Example prompt: Calculate the room modes for a rectangular studio that is 6.5m long, 4.2m wide, and 2.8m high — include modes up to 300 Hz and use an RT60 of 0.4 seconds so I can see the Schroeder frequency too.

## When to prefer this

Use this endpoint when you need to compute the acoustic resonant frequencies of a rectangular room for studio design, acoustic treatment planning, or listening room evaluation. It is purpose-built for audio/acoustic engineering use cases and returns mode type classifications and Schroeder frequency in a single call, making it more convenient than a general physics calculator.

## Known failure modes

- Missing required dimensions (length, width, height) returns a validation error
- Non-physical values (zero or negative dimensions) return an error
- RT60 not provided means Schroeder frequency will be null/omitted
- maxHz outside the 20–1000 range or count outside 1–100 returns a validation error
- Very small rooms may have extremely sparse mode lists below the requested maxHz

## How this service works

Room mode frequencies (axial, tangential, oblique) for a rectangular room, plus Schroeder frequency from RT60.

## Output

Returns a list of room mode frequencies in Hz, each tagged with its type (axial, tangential, oblique) and order notation (e.g. '1,0,0'). Also includes room volume, per-dimension first axial frequencies, the Schroeder frequency (if RT60 was provided), a summary verdict on the room's modal distribution, and any warnings or degraded-result flags.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "length",
      "width",
      "height"
     ],
     "properties": {
      "rt60": {
       "type": "number",
       "description": "Reverberation time in seconds, for the Schroeder frequency"
      },
      "count": {
       "type": "integer",
       "description": "How many modes to return, 1 to 100 (default 24)"
      },
      "maxHz": {
       "type": "number",
       "description": "Highest frequency to list, 20 to 1000 (default 300)"
      },
      "width": {
       "type": "number",
       "description": "Room width in metres"
      },
      "height": {
       "type": "number",
       "description": "Room height in metres"
      },
      "length": {
       "type": "number",
       "description": "Room length in metres"
      },
      "speedOfSound": {
       "type": "number",
       "description": "Override the speed of sound in m/s (default from temperature)"
      },
      "temperatureC": {
       "type": "number",
       "description": "Air temperature in C (default 20)"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "asOf": {
       "type": [
        "null",
        "string"
       ]
      },
      "maxHz": {
       "type": [
        "null",
        "number"
       ]
      },
      "modes": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "object",
        "properties": {
         "hz": {
          "type": [
           "null",
           "number"
          ]
         },
         "type": {
          "type": [
           "null",
           "string"
          ]
         },
         "order": {
          "type": [
           "null",
           "string"
          ]
         }
        }
       }
      },
      "source": {
       "type": [
        "null",
        "string"
       ]
      },
      "widthM": {
       "type": [
        "null",
        "number"
      
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/audio-calc-room-mode-frequencies-d31b4b21/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from audio-calc.x402tookit.com](https://www.zero.xyz/host/audio-calc.x402tookit.com/llms.txt)