Speaker L Pad Attenuator Calculator
Calculate the series/shunt resistors of an ideal constant-input-resistance L-pad and split entered power among its terms.
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Result
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Calculation steps
Work through one step at a time or reveal the complete calculation. The steps use your current inputs.
How to calculate
Solve the two-resistor constant-input-resistance attenuator from the desired voltage ratio and calculate its ideal dissipation.
K=10^(dB/20); Rseries=Z(1−1/K); Rparallel=Z/(K−1)
Worked example
At 6 dB attenuation and Z=8 Ω, series resistance is about 3.9905 Ω and shunt resistance about 8.0381 Ω. The load receives about 25.1189% of input real power.
Assumptions and input details
The load is assumed resistive and constant; real loudspeaker impedance varies with frequency. Input power is the real power at the pad, not an amplifier marketing rating. Zero attenuation gives a direct bypass with no shunt. Values are mathematical target resistances and dissipation terms, without standard-value selection, component thermal ratings or amplifier/crossover compatibility checks.
Unit definitions
Unit selection is independent of language. Each selector contains only units for its physical quantity. Calculations use defined base units internally.
SI prefixes are explicit: for example, milli means one thousandth, micro one millionth and kilo one thousand. Changing a unit changes the interpretation of the entered number.
Using this calculator
Can I enter my own problem?
Yes. Replace the example values with your own inputs. The result, calculation steps, tables and applicable diagrams update from those inputs. Blank or invalid values clear the result; example values are never silently substituted for missing inputs.
Are the results exact?
Results use floating-point arithmetic and displayed rounding. Read the formula, assumptions and any stated data precision before interpreting the result.
Is my input uploaded?
The calculation runs in your browser. No account, file upload or external AI service is required. Inputs are not saved between page reloads.
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