Importance of cable resistance and resistance between grounds on single ended cables?

[Mrcrunch08]

As the title suggests I am curious about the importance of cable resistance and if there are any tests that have been done to show what impact certain resistance combinations have? I'm not so much interested in simplified blanket tests saying this 2ohm cable performs slightly worse compared to this .5ohm cable but tests showing the difference between 3 core single ended cables and 4 core single ended cables. I never really gave it much thought until playing a game earlier today while using headphones I have played with a lot. I felt like I was getting a little more positional information than I was used to with them and the only difference was the cable. When swapping back to the old cable things became a bit less definitive. It wasn't a night and day thing but without thinking I had a better idea of distance and position with one of the cables. Because I wasn't sure what was going on I measured the cables and the one that felt less precise in position and distance measured ~1.2ohm right(+)/left(+) to 3.5mm right(+)/left(+) , ~1.3ohm right/left(ground) to 3.5mm(ground), and ~0.4ohm from right ground to left ground. The other cable measured ~0.4ohm everywhere except between right and left ground it was double at ~0.8ohms. I really don't know much about this and would really appreciate it if someone could guide me in a direction so I can understand if there is a difference or am I crazy, if so what it actually is, and why. Knowing nothing I can only guess it has something to do with cross-talk and having a lower resistance between the cups than the ground encourages cross-talk but that's just me throwing crap at a wall. Sorry for the long post and if this has been asked before. I did try to look and while found some stuff none of what I seen really mentioned the relation of resistance I am interested in.

 

[solderdude]

I have written something about this.
http://www.mediafire.com/file/82kf0r5kdckdcer/resistance%2C_impedance_and_other_issues.pdf/file
It's at the bottom of the pdf.

Basically headphone impedance is more important than a slightly higher cable resistance.
Those with a soldering iron can easily craft a cable where the common wire is replaced with a resistor.
The effect is kinda weird and affects the stereo image.
Best to experiment using headphones that don't have a varying impedance, otherwise 2 different effects are compounding the results.

 

[Speedskater]

It takes a good Ohm meter to measure values below one Ohm. A meter with a 4 terminal Kelvin Connection would be best. But a 2 terminal meter with a zeroing control might get you close.
And there are 3 segments to your question. Amplifier output impedance >> cable resistance >> headphone impedance.

 

[Mrcrunch08]

I have written something about this.
http://www.mediafire.com/file/82kf0r5kdckdcer/resistance%2C_impedance_and_other_issues.pdf/file
It's at the bottom of the pdf.

Basically headphone impedance is more important than a slightly higher cable resistance.
Those with a soldering iron can easily craft a cable where the common wire is replaced with a resistor.
The effect is kinda weird and affects the stereo image.
Best to experiment using headphones that don't have a varying impedance, otherwise 2 different effects are compounding the results.

Thank you. All of that was a big help and very interesting. I still need to take more time with the pdf and give it a thorough read. I think I let the fact I don't expect to hear any change in sound from a cable as long as the cable isn't junk send me down a hole without considering the current flow being ac or am I mistaken? Considering that it seems the issue is me having a subpar cable. I guess the crosstalk stuff is solely from the fact the negative/ground does double duty delivering a combination of L and R to each speaker?

 

[Mrcrunch08]

It takes a good Ohm meter to measure values below one Ohm. A meter with a 4 terminal Kelvin Connection would be best. But a 2 terminal meter with a zeroing control might get you close.
And there are 3 segments to your question. Amplifier output impedance >> cable resistance >> headphone impedance.

I have an old fluke. It isn't the most accurate but it lets me play around. I would love some better toys to play with though you guys would get a lot more dumb questions. lol. Thankfully two of those three in my case was a constant so the change had to come from the wire. Before that pdf I haven't even thought to think about the other two things and how they may impact the change the wire could have. I completely ignored the fact I have high impedance headphones with a wire out one side that have fantastic imaging despite the wiring be much like what I described earlier. The headphone I noticed it first with was 38ohm and the other headphone I have that uses the same cables is 32ohm and it was noticeable with that too. The more I look in to it the more I think I just may have a crap cable and not sure what is going on.

 

[solderdude]

I guess the crosstalk stuff is solely from the fact the negative/ground does double duty delivering a combination of L and R to each speaker?

correct. The common wire resistance combined with the total resistance (output R amp+headphone impedance) ratio determines this.
It can become audible when L and R signals differ, which is often the case with any sounds not designed to come from the center.

I would say get some assistance to determine audibility. Blindfold yourself and have another person pull out the cable and either re-insert it or change it to the other cable. That person must do this random and take notes. After 15 attempts you will know for certain if you truly hear differences.
Fun and educational experiment that is easy to do.