Source: https://guthlabs.ai/docs/instruments/passive-crossover-frequency-calculator/implementation/

instrument implementation / implementation-contract

# Passive Crossover Frequency Calculator implementation

A source-bound implementation contract for Passive Crossover Frequency Calculator; deployment and executable qualification remain separate.

Status: **VERIFIED_CLEAN**Lifecycle: **implementation-contract**

## Binding contract

This record describes what an executable surface must bind and validate. It does not claim that a public calculator, package, or production route is deployed.

**Record owner**: Guth Instruments

**Lifecycle**: verified-clean

**Evidence ID**: t2-037

**Effect**: Computation or source lookup only

## Input and validation requirements

Zero target frequency produces a division-by-zero undefined result, and zero or negative driver impedance exposes invalid or ambiguous inputs. The instrument should validate impedance and target frequency before calculation and explicitly define whether impedance magnitude or signed impedance is used.

## Required corrections

No binding erratum is attached to this unique-name record. Implementers must still preserve the declared units, domain, and failure behavior.

## Inspectable interface fixture

The sample below is evidence for interface and validation tests, not a production implementation.

````
{
  "inputs": {
    "filter_order": 1,
    "filter_type": "RC low-pass",
    "driver_impedance_ohm": 8,
    "target_fc_hz": 2000
  },
  "expected_outputs": {
    "capacitance_uF": 9.947184
  },
  "working": "C=1/(2πRC)=1/(2×π×8×2000)=1/(100530.9649)=0.000009947184 F. Convert to µF: 0.000009947184×1,000,000=9.947184 µF."
}
````

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/passive-crossover-frequency-calculator/>)[02**Mechanism**](<https://guthlabs.ai/docs/instruments/passive-crossover-frequency-calculator/mechanism/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/passive-crossover-frequency-calculator/qualification/>)

## Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

- `VERIFIED_LEDGER.json`

- `evidence-tranche2/tranche2-results.json`