Calculation of cable length, cable capacitance C, and cutoff frequency cable attenuation treble loss damping microphone mic cable capacity wires XLR capacity

Calculation of Cable Attenuation (Loss)
● Cable Length and Cable Capacitance ●
Treble Loss (Attenuation) and Cutoff Frequency
Line capacitance and Line calculation
Cut-off frequency = corner frequency = crossover frequency
= half-power frequency = 3 dB frequency = break frequency is all the same.

The used browser does not support JavaScript.
You will see the program but the function will not work.

This is not about coaxial cables, antennas and satellite frequencies.
Here we have a look at a normal audio, mic or microphone cable.

Cable and treble attenuation
treble cut filter (low pass)
Simplified principle
C = C_spec · d

A frequently asked question is at which cutoff frequency f_c the microphone cable has a (−) 3 dB loss of treble? Which treble frequencies are attenuated? Which length d a cable can have to reach this attenuation? How are high frequencies attenuated by the length of the cable?
Cables are characterized by the capacity of the cable between the conductors, the resistance, inductance of the cable along the conductor, and the current crowding, which boost the resistance at high frequencies. The microphone cable usually has a capacitance from wire to wire of about C_spec = 100 pF per meter.
The line resistance, and the inductance is usually negligible in practice. Each wire has an unavoidable cable capacitance, that leads to the attenuation of high frequencies, called cable loss. Because the input resistance (load) is large against the small output impedance (source), the input impedance (load) can be neglected.

Calculating the treble cutoff frequency f_c of a cable

f_c = Cutoff frequency at (−)3 dB treble loss in Hz

Z_out = Output impedance of microphone, source impedance

C_spec = Specific capacitance of the cable in pF per m cable length

d = Cable length of the cable in m C = C_spec × d

1 pF (Picofarad) = 10⁻¹² F (Farad)

Formula for the cutoff frequency f_c of the (−)3 dB treble attenuation:
Cable cutoff frequency - sengpielaudio

Another frequently asked question is of how long can the microphone cable be,
without having treble loss?

Cable length or line length

Calculation of the length of a cable at 3 dB treble attenuation

d = Cable length in m

f_c = Cutoff frequency at (−)3 dB treble loss in Hz

Z_out = Output impedance of microphone, source impedance

C_spec = Capacitance in pF per m cable length C = C_spec × d

1 pF (Picofarad) = 10⁻¹² F (Farad)

Formula for the length of the cable d and a given cutoff frequency f_c:
Cable length - sengpielaudio

If you want to know how long the cable can be and permit a level attenuation
of only 1 dB, you need to enter the double value of the cutoff frequency.

Cable characteristic impedance is a cable characteristics which is only
valid for radio frequency signals. Multimeters use DC current for resistance
measurements, so you cannot measure the cable impedance using your
multimeter or other simple measurement equipment.

Capacitance C, frequency f, and capacitive reactance XC

Converting feet to meters and vice versa
for U.S.A only. It's better to go metric - like the whole world.

To use the calculator, simply enter a value.
The calculator works in both directions of the ↔ sign.

Cable, wire, and wiring - Conversion of diameter to cross-sectional area

back

Search Engine

home


Feet (ft) ft	↔	Meters (m) m

1 foot = 0.3048 m 1 meter = 3.280839895 ft