This audio cable business is getting out of hand...

[valkeryie]

Only if you do it double blind.

We did it blind drunk. Does that count? Or perhaps "Blind High"? Or "Blind High and Drunk"?

Seriously, once we got started nobody could tell which cable was being played - I forgot to write that down - but as we flipped back and forth - not knowing which cable was in line - we could hear no difference.

 

[Speedskater]

How does that resistance and capacitance affect the audio signal?

End-to-end resistance has impact on common impedance coupling noise. There can be up to 25dB difference in this noise with different RCA cables used by audiophiles. even so it shouldn't be a problem with short cables (say 3 meters/10feet). But longer than 30 feet it can be a problem.
As to capacitance, no audible difference with any reasonable circuit designs, but it's nice to have.

 

[Julf]

We did it blind drunk. Does that count? Or perhaps "Blind High"? Or "Blind High and Drunk"?

Seriously, once we got started nobody could tell which cable was being played - I forgot to write that down - but as we flipped back and forth - not knowing which cable was in line - we could hear no difference.

I totally believe the "no difference" part, not sure about the "even with the solid silver IC the difference was fleeting - very small and one had to listen closely to tell the difference" part.

 

[Julf]

End-to-end resistance has impact on common impedance coupling noise. There can be up to 25dB difference in this noise with different RCA cables used by audiophiles. even so it shouldn't be a problem with short cables (say 3 meters/10feet). But longer than 30 feet it can be a problem.

25 dB might sound like a lot, but it all depends on what your reference level is. How many dB below the signal would that be?

Even 10 m (30 feet) is a very short distance in relation to the wavelength (hundreds of meters), and most impedance effects only become relevant when you get close to half a wavelength.

 

[FrantzM]

I use GhentAudio.... there are 2 wire and 4wire versions of their cables. They look good and work fine and they are relatively cheap and come in sizes that make the stack look clean.

These are on my list too.

 

[DonH56]

For an audio interconnect, the shield coverage and resistance matters when considering noise rejection (EMI/RFI suppression), and that can be important in an audio system. Not a big deal for many systems, natch. It also may help (or make worse) a ground loop. As far as the audio signal itself, meh. But I agree with @Speedskater , it's cheap enough to get a good cable with good connectors, so might as well. May not work any better than the <$10 Monoprice or whatever but in the overall scheme of things not a big-budget item.

IMO - Don

 

[trl]

Quite a long thread here I'd say, but let's all not forget that on a 20KHz bandwidth and with 1...2m long RCA cables even an Amazon Basics cable should do the job very well. If somebody thinks that hears differences between an expensive 1000 USD silver cable and a 50 USD cable I challenge him/her to use the most difficult audio test possible: square-waves test! Yes, a dual-spot scope and simple measurements at 1...2V RMS with different quality cables at 20Hz, 100Hz, 500Hz, 1KHz, 5KHz, 10KHz, 15KHz and 20KHz, then post back here differences.

 

[Speedskater]

Even 10 m (30 feet) is a very short distance in relation to the wavelength (hundreds of meters), and most impedance effects only become relevant when you get close to half a wavelength.

It has nothing to do with wavelengths or Radio Frequency Characteristic Impedance. It's about low frequency end-to-end resistance. It's about power line caused leakage currents.

Bill Whitlock writes:

Leakage Current Effect - A Calculated Example
• A 25-foot cable (foil shield, #26 AWG drain wire) has an end-to-end shield resistance of 1 Ω
• Measured leakage current between the ungrounded devices is 316 μA (well under the UL limit of 750 μA)
• From Ohm’s law, noise voltage E = I x R = 316 μA x 1 Ω = 316 μV
• Consumer −10 dBV reference level = 316 mV
• Signal to Noise ratio = 20 x log (316 mV⁄316 μV) = 60 dB
• This is 35 dB worse than an audio CD!
• Same length of Belden #8241F cable, with its shield resistance of only 0.065 Ω, makes S⁄N 84 dB, an improvement of 24 dB!

From a noise perspective, shield resistance is the most important parameter of all.
How many times have you seen it specified on a data sheet or in advertising hype?
I rest my case about clueless manufacturers!

Bill Whitlock, 9/4/2012 Overview of Audio System Grounding & Interfacing page63

 

[Julf]

Leakage Current Effect - A Calculated Example
• A 25-foot cable (foil shield, #26 AWG drain wire) has an end-to-end shield resistance of 1 Ω
• Measured leakage current between the ungrounded devices is 316 μA (well under the UL limit of 750 μA)

What is causing that leakage current?

 

[Julf]

There is of course a simple solution to all these concerns - balanced/differential connections.

 

[ajawamnet]

High power antennae are not the same as home stereos, just as Formula 1 cars are not the same as my dad's VW. Do a blind ABX with cables. Don't rely on the theoretical.

That'd I'd have to disagree with...

 

[Julf]

That'd I'd have to disagree with...

Sure, but hopefully you have a good rationale and some evidence.

 

[ajawamnet]

And even the theory tells us that at audio frequencies and reasonable distances, it matters squat all.

That I'd agree with, tho I have seen some weird mismatches in pro audio gear that cause bizarre behavior that we've actually been able to measure on test gear. Again it all depends on the input and output impedance of the gear and the topology of the circuits involved. In these situation the mfg's were doing some strange Class A stages that didn't like cables with more than a few dozen pF/m. It would generate some strange artifacts and go into oscillation.

But at the paltry low bandwidth audio, it's not usually critical.

 

[ajawamnet]

Sure, but hopefully you have a good rationale and some evidence.

Again - I'd refer to the work Heaviside did and the book I link to.

There is of course a simple solution to all these concerns - balanced/differential connections.

That doesn't always make things better - again based on the circuits involved. For instance transformer vs transformerless, the input and output impedances - the math is there. Just calc it or use a spice simulator of a lumped model.

 

[Julf]

That I'd agree with, tho I have seen some weird mismatches in pro audio gear that cause bizarre behavior that we've actually been able to measure on test gear. Again it all depends on the input and output impedance of the gear and the topology of the circuits involved. In these situation the mfg's were doing some strange Class A stages that didn't like cables with more than a few dozen pF/m. It would generate some strange artifacts and go into oscillation.

Sure, and there is of course the case of that well-known British audio brand who left out the zobel network on the output of their amps, making them oscillate unless you use the right cables.

 

[ajawamnet]

Sure, and there is of course the case of that well-known British audio brand who left out the zobel network on the output of their amps, making them oscillate unless you use the right cables.

No, this was line level, balanced audio stuff.

 

[carlob]

Sure, and there is of course the case of that well-known British audio brand who left out the zobel network on the output of their amps, making them oscillate unless you use the right cables.

Actually not only Naim but also the old Exposure amps.

 

[Julf]

That doesn't always make things better - again based on the circuits involved. For instance transformer vs transformerless, the input and output impedances - the math is there. Just calc it or use a spice simulator of a lumped model.

As long as you apply the math correctly. The main point is that any ground currents are kept separate from the signal path, so cable and shielding resistance becomes a non-issue.

 

[ajawamnet]

Actually not only Naim but also the old Exposure amps.

Zobel networks has to do with the impedance of voice coils and the characteristic rise - see http://www.wavecor.com/html/zobel_networks.html

If you want to see what a speaker is doing impedance wise, get one of these:
https://www.parts-express.com/dayto...er-based-audio-component-test-system--390-806

Here's a sweep of a crap speaker we had in the lab:

 

[Julf]

Zobel networks has to do with the impedance of voice coils

They are used in speakers/crossovers to compensate for voice coil impedance, but also in amps to avoid oscillation caused by cable capacitance.