[coinmaster]

I know a lot of people hate the idea that cables sound different but is there any agreement that wire purity contributes?
For example Mogami cable witch is made of OFC copper vs other expensive OCC copper with 7n purity type 6 litz with cotton and all that other jazz.

 

[Speedskater]

It contributes less than shortening the length of a 10 foot cable to 9 feet 6 inches.

 

[StanD]

  It contributes less than shortening the length of a 10 foot cable to 9 feet 6 inches.

+1 Other than aesthetics and ergonomics, even lamp cord sounds good.

 

[tangent]

Only wire made with unicorn tears conveys the proper musical signal.

 

[StanD]

  Only wire made with unicorn tears conveys the proper musical signal.

I prefer Unobtanium as it has better speed and better microdetails, much better than Silver.

 

[coinmaster]

So are you saying wire purity doesn't affect sound quality?

 

[StanD]

  So are you saying wire purity doesn't affect sound quality?

Nope, it's simply a matter of the resistance and capacitance, of which either is more than low enough with most decent cable. This forms a simple RLC circuit between the Amp and the cans. If your cans are Planar Magnetic then there is no L to speak of.

 

[coinmaster]

Doesn't less purity = more resistance?

 

[StanD]

  Doesn't less purity = more resistance?

The differences are far too small to make a difference.  I measured the capacitance and resistance in my stock HD600 cable and it affected radio frequencies far above audio.

 

[tangent]

  I measured the capacitance and resistance in my stock HD600 cable and it affected radio frequencies far above audio.

 
Well, there's actually an interesting point. Many circuits that run just fine with either a negligible load or a purely resistive load get downright cranky when you drop a few hundred pF on its output. Many audio cable designs are actually surprisingly high in capacitance, given that they would be considered poor capacitor designs if that's what you were trying to accomplish.
 
Some of these crazy designs you see...I wonder how many of them have even higher capacitance than something more mainstream.

 

[StanD]

   
Well, there's actually an interesting point. Many circuits that run just fine with either a negligible load or a purely resistive load get downright cranky when you drop a few hundred pF on its output. Many audio cable designs are actually surprisingly high in capacitance, given that they would be considered poor capacitor designs if that's what you were trying to accomplish.
 
Some of these crazy designs you see...I wonder how many of them have even higher capacitance than something more mainstream.

If a headphone amp can't handle a headphone cable's capacitance, I'd get a different amp. The ones that are typically unstable are those using large amounts of negative feedback (have large open loop gain) and obviously are poorly designed. I would be shocked if any of these break into oscillation. Can you name some of the offending products?

 

[Speedskater]

   
Well, there's actually an interesting point. Many circuits that run just fine with either a negligible load or a purely resistive load get downright cranky when you drop a few hundred pF on its output. Many audio cable designs are actually surprisingly high in capacitance, given that they would be considered poor capacitor designs if that's what you were trying to accomplish.
 
Some of these crazy designs you see...I wonder how many of them have even higher capacitance than something more mainstream.

If this was about 1980 all that would be true. But amplifier design has come a long way in the past 35 years.  And the few speaker cables with way high capacitor values that we saw in the 1980's have all but disappeared.

 

[JWolf]

Sorry, but you people are wrong. Different types of cables can sound different. You may not be able to measure this, but you can hear it.

 

[tangent]

  Sorry, but you people are wrong. Different types of cables can sound different. You may not be able to measure this, but you can hear it.

 
Then you should be able to prove it with a reproducible test.
 
Science is hard, but we've had several hundred years of practice doing it well, so we have a whole list of things required to pull off a good test of this sort:
 

• Specify the products to be tested precisely, so that others can build or buy identical replacements, within a reasonable amount of measurement error. Specify those measurement bounds. Example: Cable A shall be made of 6.0 feet of such-and-such cable with a Brand X Type Y outer jacket, soldered to a thus-and-so connector with type Whatsit solder, having 0.0032 Ω of resistance and 123 pF of capacitance +/- 0.1% as measured on a calibrated 5 ½ digit HP 34401 DMM. Cable B shall be identical to Cable A except that it uses 6.0 feet of this other inner cable type, giving 0.0033 Ω of resistance and 234 pF of capacitance. Test to be done with a Brand Q Model P headphone amplifier with the Bizzabong upgrade.
• An adequate sample size. "I made my aunt listen to both cables, and she liked the pink one better" is not good enough.
• A double-blinded test. This means you cannot experiment on yourself!
• Publish your data. "My buddies all sat around the amp smoking unspecified herbal products and decided cable A sounded better than cable B" is not "published data." How many participants did you use? How many separate tests did you subject each participant to? What music did you use? What was the volume level of the amplifier? (Which must be given in some reproducible measure, such as Vac RMS of a full-scale test signal at the test amp's volume setting.) Most importantly, what were each participant's responses? Without the raw data, we cannot know the data's p value.
• Select and specify a randomization method. For a psychoacoustic test such as this, I'd suggest ABX testing. If you like some other method better, specify it, and be prepared to defend your choice rationally.
• Independently replicate the test multiple times. If two groups come up with different results after following the test protocol you get from following the above points precisely, the test is not reproducible, and is therefore scientifically invalid. There are many reasons this can happen, all of which mean the original test did not prove what it claims to have done.
• Should you manage to get completely through that gauntlet and still have an independently reproducible test difference, vary one detail of the test, then go back to step 2. For instance, if the difference disappears when you don't use the Bizzabong headphone amplifier upgrade, that suggests some interaction between the three items under test (one amplifier upgrade, plus two cables) which is responsible for the difference, which calls into question the difference in the cable being the reason for the difference in the test results.

 
I'm probably missing something important here which someone with expertise designing scientific test methodologies could point out. The important thing here is not to make the test pointlessly difficult, but to increase its statistical power sufficiently to overcome the psychoacoustic difficulties inherent in the test. With insufficient statistical power, we must disregard the test results.
 
On point 3: If your only aim is to please yourself, that's perfectly fine. I am a committed DIYer, which means I cannot honorably rail against any person who decides that they need to build a $500 headphone cable in order to achieve happiness. Just don't try to make me believe, should that cable indeed induce happiness, that your "test result" is a scientifically-useful data point. Go ye forth and listen to your headphone cable. I sincerely wish you all the enjoyment you can squeeze out of it.

 

[Brooko]

  Sorry, but you people are wrong. Different types of cables can sound different. You may not be able to measure this, but you can hear it.

 
Actually - if you re-read what they've posted, you'll find they are correct.  Typically when a cable has produced a different sound for me, I've gone back and done measurements.  Every time I've done it, the cable has has slightly different resistance which has then raised or lowered the volume slightly.  When I volume match - the difference disappears.  It's not magic we're talking here - merely science.  If it is so easy to discern, then why is it that no-one has successfully ABXed under controlled conditions when two cables are compared?
 
If you want to send me a couple of different sounding cables - I'll measure them for you.