A New Believer

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

Al: Thanks for the balanced comment. That is what I said in my original post. And that is why I recommended the Anti-cables. They are simple in construction and more likely to be a better match to the driving amplifier.

Shadorne: The point I was making is this. There is NOTHING that is absolutely understood in our hobby. The example I gave you was the one that supported "CD reproduction was perfect" It turns out that as envisioned it is not. Just because one cannot measure it or do not have an explanation of why a certain thing goes against the "Mainline Thinking" does not mean it does not occur. While I agree that all the other items you list are very important and should be optimized the bottom line is this.I also agree with you that there is a LOT of snake oil out there and if you are not technically savvy can get burned.

You have a CHAIN and every link in the chain right up to your ears modifies the sound. In my opinion the simpler these interfaces are the less likely that you will have a large interaction between them. So I would refrain in general with "grossly inaccurate" unless you have a very good grasp of the interactions of even a few feet of wire that has capacitance, inductance and resistance and a feedback amplifier with a speaker load.

Al: There is a fly in the ointment though. Speaker loads are very far from being predictable speaker to speaker. The low output impedance of an amplifier will help but as I said in the first post you have the cable and the speaker in series. Feedback amplifiers can measure well under continuous drive but can fare badly in transient conditions.

Regards,

J

04-20-11: Stops
Al: There is a fly in the ointment though. Speaker loads are very far from being predictable speaker to speaker. The low output impedance of an amplifier will help but as I said in the first post you have the cable and the speaker in series.

I agree.

Implicit in my comment about the predictability of the interactions between cable impedance and the impedance and other characteristics of what is being connected was the thought that the effects of any given cable will vary widely depending on what the cable is connecting. Sometimes in opposite directions, in fact. Nevertheless they are generally predictable for a given combination of cables and components, assuming the technical parameters of both are known.

For example, a low capacitance interconnect cable used as a line-level interconnect will tend to have GREATER bandwidth/faster risetime than a higher capacitance cable, as a result of its interaction with the output impedance of the component that is driving it. That same low capacitance cable, if used as a phono cable in conjunction with a moving magnet cartridge, will tend to have LOWER bandwidth/slower risetime than a higher capacitance cable, as a result of its interaction with the inductance of the cartridge. Same cable, exactly opposite effects depending on what it is connecting. Those effects will sometimes occur at frequencies well below 20kHz.

Feedback amplifiers can measure well under continuous drive but can fare badly in transient conditions.

Agreed also. Although in typical situations I would expect cabling to play a role in that which is minor or negligible, relative to the performance of the amplifier itself and to the sonic effects of amplifier/speaker interaction.

Regards,
-- Al