04-20-11: Stops
Shadorne: Interesting but the rise and fall time of the signal is relevant and therefore the impact of the impedance is also relevant even at "audio" frequencies.
Keep in mind that the risetimes and falltimes of the source material, the source component, the amplification, the speakers, and our ears are all limited, and with the exception of some amplification components do not extend into the rf region.
And even if "transmission line" or other cable effects that occur at rf or upper ultrasonic frequencies were somehow audible despite the limited bandwidth/risetime/falltime of everything else that is involved, there would seem to be no reason to expect those effects to be predictable, or to be consistent from system to system, or to be significantly correlated with price.
I certainly agree, though, that impedance can be important in analog audio cables. But the reason for that is because of the interaction of its constituents (resistance, inductance, capacitance) with the impedance and other characteristics of the components the cable is connecting. Those interactions are technically predictable. More importantly, pretty much any given set of impedance parameters is obtainable across most of the price spectrum.
Regards,
-- Al