LS Cables - Transmission Line vs Lumped Element
 

"Jim Lesurf"

A while ago there was some discussion about loudspeaker cables and the
relative merits of analysis using the transmission line and AC lumped
element approachs. I've now done a page on this which people may find
interesting. It is at

http://www.st-andrews.ac.uk/~www_pa/...g/howlong.html


** Figure 4 shows the " lumped component " model of a speaker cable that Jim
used.

But why the heck is C shown at the speaker end and so coming AFTER the
cable's inductance ???

Any cable ( whether co-axial, twin wire, twisted pair or woven pair )
exhibits pure capacitance when the far end is not loaded. So C ought to be
at the input end - then at least the cable model would pass open and short
circuit load testing.

In fact, the model as shown in fig 4, resolves to simply cable L plus R in
series with a pure 8 ohm load - over the frequency range graphed - cos
the 8 ohm load completely swamps the effect of the C values involved.




...... Phil