Description
Multiply measured frequency by 2^suppliedOctaveOffset and divide by reference.
Frequency ratios express pitch relationships, while cents express their logarithm relative to an octave. Playback speed and pitch-preserving time changes obey different models; the relevant reference and physical assumptions must be supplied.
Multiply measured frequency by 2^suppliedOctaveOffset and divide by reference.
When to use this tool
Use Recording Pitch Reference Factor when you need a stated pitch-ratio, reference or playback-speed term.
How to use the tool and how it works
- Enter measuredFrequency, referenceFrequency, suppliedOctaveOffset. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read normalizedFrequency, ratio. Use the output convention below.
Require positive measured/reference frequencies. Multiply measured frequency by 2^suppliedOctaveOffset and divide by reference.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| measuredFrequency | Measured Frequency | Required. Finite number; strictly above 0. |
| referenceFrequency | Reference Frequency | Required. Finite number; strictly above 0. |
| suppliedOctaveOffset | Supplied Octave Offset | Required. Safe integer. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| normalizedFrequency | Normalized Frequency | Required. Finite number. |
| ratio | Dimensionless ratio under the numerator/denominator convention above. | Required. Finite number. |
{
"input": {
"measuredFrequency": 220,
"referenceFrequency": 440,
"suppliedOctaveOffset": 1
},
"output": {
"normalizedFrequency": 440,
"ratio": 1
}
}Limitations and assumptions
- Octave offset is an explicitly supplied exponent, not necessarily inferred or restricted to a whole octave. No pitch detection or tuning-standard selection occurs.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Use calibrated audio measurements and the appropriate processing method for actual recordings. Retain cultural tuning context and verify reference frequency, speed history and instrument assumptions separately.
References
Similar or alternative tools
- Public Tuning Reference Pitch Shift
Scale by target/original and return factor, shifted frequency and 1200×log2 factor cents.
- Recording Pitch Drift Two Anchors
Interpolate their natural logarithms, exponentiate for ratio and convert interpolated log ratio to cents.