Theater Calculators

Signal, cables & storage

Audio Cable Capacitance / Treble Loss Estimator

Cables are capacitors. With a high source impedance they roll off treble. Keep f-3dB well above 20 kHz.

Inputs

Units
pF/m

From the data sheet; pF/ft × 3.28 = pF/m.

m
Ω

Many preamps are <100 Ω; vintage gear can be 600–2 kΩ; a passive 10 kΩ pot up to 2.5 kΩ.

Results

Total capacitance
800pF
−3 dB frequency
331,573Hz
Loss at 20 kHz
-0.02dB

The Result is indicative and educational. It does not constitute a design, a technical opinion or medical advice and does not replace calculations or verification by a person with the appropriate qualifications and authorisations. Before purchase, installation or use in practice – in particular in electrical installations – the Result should be verified by a qualified specialist. Details: Terms of Service, point 4.

Example products

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Calculation method

C = pF/m × length. f3 = 1 / (2π R C). Loss at 20 kHz is −10 log10(1+(20k/f3)²).

Exact formula

f3 = 1/(2πRC). Limits: lumped C, no inductance, no dielectric absorption, unbalanced RCA assumed, the receiving input’s own capacitance is not added.

Frequently asked questions

XLR better?

Balanced helps noise, not this RC filter, unless the driver Z is lower.

What pF/m is typical?

50–150 pF/m for decent interconnects. Microphone snake can be higher.

Is 0.3 dB audible?

Hardly: most adult hearing fades out near 20 kHz. What you can hear is the slope below it; when 20 kHz is 4 dB down, 10 kHz is already about 1.4 dB down.

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