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[luis Markson]

I've read that cable capacitance and inductance act like a RC & RL LPF. The answer may be beyond what can be quickly understood..., however, what are "RC & RL" Low pass filters?

[John Roberts {JR}]

I've read that cable capacitance and inductance act like a RC & RL LPF. The answer may be beyond what can be quickly understood..., however, what are "RC & RL" Low pass filters?

R= resistance
C= capacitance
L= inductance

Resistance is frequency independant constant  opposition to current flow.

Capacitance is opposition to instantaneous voltage change, so looks like a decreasing resistance with increasing frequency.

Inductance is opposition to current change, so looks like an increasing resistance with increasing frequency.

Combination of R with C  or R with L can make a simple one pole (6 dB/octave) high pass or low pass filter.

Wire has R, L, and C, but generally the C and L is small wrt the R so can be ignored for all but long distances. At very long distances (or very high frequency)  the cable takes on a characteristic impedance. This is not important to know for audio, but what is meant by 50 ohm cables for some digital signals or 600 ohm twin lead for TV antennas.   

Welcome to TMI land...

JR

[Brad Weber]

http://en.wikipedia.org/wiki/RC_circuit
 
http://hyperphysics.phy-astr.gsu.edu/hbase/electric/filcap2.html
 
http://www.electronics-tutorials.ws/filter/filter_1.html
 
http://en.wikipedia.org/wiki/RL_circuit
 
http://en.wikipedia.org/wiki/Low-pass_filter
 
http://en.wikipedia.org/wiki/High-pass_filter

[luis Markson]

thanks & thanks

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