Speaker/Load Impedance Matching Calculator

Inspectable records

Ledger state

The current ledger marks this instrument verified clean within the source-bound verification corpus.

Area

Electrical & Electronics Engineering — Circuits, Power Systems, Electronics Lab

Tranche

tranche-5

Evidence ID

t5-222

Ledger rows

1

No ledger note is attached.

Review findings

The nominal series and parallel impedance concepts are valid, and the honest label appropriately states that real speaker impedance varies with frequency. The instrument cannot honestly claim to compute maximum power handling or target-load matching until it defines the exact formulas, adds speaker power ratings and amplifier operating assumptions, adds a target impedance input, and specifies unit handling and validation constraints.

Formula and scope findings

• The impedance formula is only described indirectly; the implementation must explicitly use Z_series = ΣZi and Z_parallel = 1/(Σ(1/Zi)) for nominal impedances.
• Maximum power handling cannot be calculated from the listed inputs because individual speaker power ratings and the relevant amplifier voltage/current or power conditions are missing.
• Power handling described as “min of series, sum-ish for parallel” is not a standard formula. Series and parallel power limits depend on each speaker's impedance, power rating, frequency, and how amplifier voltage or current is distributed.
• The claimed target-load matching calculation is underspecified because no target impedance input or pass/fail matching criterion is listed.
• For parallel combinations, zero or near-zero impedance must be rejected; the reciprocal formula is undefined at zero and can produce unsafe misleading results near zero.

Unit assumptions

• All impedance values are nominal RMS impedances in ohms (Ω), not instantaneous frequency-dependent impedance.
• All speakers in a combination are assumed to be evaluated at the same nominal reference frequency and under the same impedance convention.
• If units other than ohms are accepted, values must be normalized before calculation; 1 kΩ = 1000 Ω.
• The resistor-style formulas describe only nominal load impedance and do not model phase angle, reactive behavior, crossover networks, or impedance minima.

Boundary hardening

BREAK_CLAIMED · SELF_FLAGGED

The specification exposes invalid-input and undefined-result hazards at zero or nonphysical impedances, and its parallel power-handling wording is convention-dependent. A robust implementation must reject nonpositive impedances, guard a zero parallel denominator, and label whether power handling is total pair power or per-speaker power.

Errata and corrections

No applied erratum is attached to this unique-name record.

Inspectable example

4 review vectors are recorded. One source-bound sample is shown below.

{
  "inputs": {
    "speaker_impedances": [
      {
        "value": 8,
        "unit": "ohm"
      },
      {
        "value": 8,
        "unit": "ohm"
      }
    ],
    "topology": "series"
  },
  "expected_outputs": {
    "combined_nominal_impedance_ohm": 16,
    "power_handling": null
  },
  "working": "Series formula: Z = Z1 + Z2 = 8 Ω + 8 Ω = 16 Ω. Power handling is undefined from the supplied inputs because no speaker power ratings or amplifier operating condition are provided."
}

Related workflows

No source-defined multi-instrument workflow membership is recorded.

Sources and evidence

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

• VERIFIED_LEDGER.json · VERIFIED_CLEAN
• evidence-tranche5/tranche5-results.json
• BOUNDARY_HAZARD_CATALOG.json