Please enter all required numeric values.
RESULTS
Input Parameters Specification
Capacitance CCable capacitance per meter in pF/m, used to estimate high-frequency treble roll-off.
Cutoff Frequency fThe 3 dB treble attenuation frequency where the audio or RF signal begins to reduce.
Impedance ZSource or circuit impedance in ohms affecting cable capacitance loading.
Cable Length dMaximum cable length in meters at the selected 3 dB attenuation point.
Practical Operational Examples
Audio Cable Treble Loss
Estimate how long a guitar, microphone, or signal cable can be before audible high-frequency attenuation appears.
Impedance and Cable Capacitance
Compare different pF/m cable ratings and source impedances to reduce treble roll-off and signal loss.
Diagrams & Theory
A cable behaves like distributed capacitance. Together with the source impedance, it forms a low-pass response where the 3 dB point marks the treble attenuation frequency.
Formulas & Mathematical Logic
Step 1: Convert capacitance from pF/m to F/m: C = capacitance × 10^-12.
Step 2: Use cutoff frequency f in Hz and impedance Z in ohms.
Step 3: Cable length d = 1 / (2 × π × Z × C × f).
Step 4: Display d in meters with 3 decimal places, preserving the original calculation logic.
Step-by-Step Example
Example: cable capacitance = 100 pF/m, cutoff frequency = 10000 Hz, source impedance = 50000 Ω.
Convert capacitance: 100 pF/m = 100 × 10^-12 F/m.
Cable length d = 1 / (2 × π × 50000 × 100 × 10^-12 × 10000).
The result gives the approximate cable length where treble reaches the 3 dB attenuation point.
How to Use This Calculator
Enter the cable capacitance rating in pF/m. This value is usually listed in the cable datasheet.
Enter the treble cutoff frequency in Hz where you want to check the 3 dB point.
Enter source or circuit impedance in ohms.
Click Calculate to get the estimated maximum cable length in meters.
About This Calculator
Estimate cable length before noticeable treble roll-off.
The CalcBoy Cable Length at 3 dB Treble Attenuation Calculator helps estimate how cable capacitance and source impedance limit high-frequency response.
Long cables are not only pieces of wire. Every meter adds capacitance, and that capacitance loads the source impedance. In audio systems, guitar cables, pedalboards, passive pickups, sensor wiring, and high-impedance signal paths, this capacitance can form a low-pass filter. The result is reduced treble, softer attack, or a duller signal when the cable becomes too long.
This calculator uses cable capacitance per meter, cutoff frequency, and impedance to estimate the length where the signal reaches the 3 dB attenuation point. A 3 dB point means the signal level has dropped enough to be considered the practical corner frequency of the cable-source RC network. It is especially useful when comparing low-capacitance cables, planning long audio runs, checking passive guitar tone loss, or deciding whether a buffer is needed.
Best UseAudio cable, guitar cable, sensor lead, and high-impedance signal path planning.
Capacitance EffectHigher pF/m cable capacitance reduces the usable cable length.
Impedance EffectHigher source impedance makes treble roll-off happen sooner.
Design TipUse low-capacitance cable or a buffer for long high-impedance audio lines.
Tip: Passive guitar pickups and high-impedance circuits are much more sensitive to cable capacitance than low-impedance buffered outputs. If the calculated length is short, a buffer can keep treble response more consistent.
Frequently Asked Questions
What does 3 dB treble attenuation mean?
It means the signal level at the selected high frequency has dropped by about 3 dB, which is commonly treated as the cutoff point of a simple RC low-pass response.
Why does cable capacitance reduce treble?
Cable capacitance combines with source impedance to form a low-pass filter. Higher frequencies are reduced first, which can make the signal sound darker.
What cable capacitance value should I enter?
Use the cable datasheet value in pF/m. Audio and instrument cables often publish capacitance per meter or per foot.
Why does source impedance matter?
A higher source impedance interacts more strongly with cable capacitance, lowering the cutoff frequency and reducing usable cable length.
Can this calculator be used for guitar cables?
Yes. Passive guitar pickups are high impedance, so cable capacitance can noticeably affect treble response.
How can I reduce treble loss?
Use shorter cable, lower-capacitance cable, lower source impedance, or a buffer/preamp before the long cable run.
Is this exact for every audio system?
No. Real systems may include pickup inductance, amplifier input capacitance, tone controls, and cable construction effects. This calculator gives a practical RC estimate.
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