[brconner]

Hey All,
 
So I've read a lot about how cables will improve the sound and also a lot about how it's a marketing scheme to make money. Myself personally, I'm biased to believe that it's snake-oil and the effects people are hearing is purely a placebo effect. Now, while I say that, as an engineer if I can find quantitative data then I'll change my opinions.
 
Here's what I'd like to do. I would like people to list out the different types of cables, not brands, and I'll try to get as many of them as a can. When I say this I mean, silver wire, silver coated copped wire, different gauges, braided/solid conductor etc. I do not mean such and such a brand for the such and such headphone. I'm not made of money sadly, so I don't want to spend a whole lot of money on this. After I get a good list, I'll try to get some materials and perform some tests. If you want to send me some actual cables I'd be happy to test them as well.
 
Here's what I plan on doing for the test...
 
The measurements I'll be taking will be frequency magnitude/phase response and THD from 5Hz to 40KHz using an ATS-2 audio measurement system. I'll measure all three of the following voltages: 5Vrms, 1Vrms and 10mVrms. The source impedance will be 20 ohms and 50 ohms as well if I can time.
 
I'll try to use 3 different lengths for each cable type: 3 meters, 2 meters, and 1 meter. I plan on testing the longest length first and and the cutting it to obtain the other two lengths just so that I'm using the same cable and that will keep the test more consistent.
 
Measurements will be taken from the following configuration; equipment output ground to equipment input ground and then the cable will be the active line between the input and output.
 
My expectation is that so long as the connection is solid (the wire isn't broken or physically worn down anywhere), there won't be any differences in magnitude, phase, or thd. In my experience testing different measurement probes, even really crappy ones will measure slow signals perfectly. A slow signal is anything less than 100kHz. If there is any measureable difference I think it will have to do primarily with the length of the wire which is really just increasing its resistance.
 
Anyways, if people show interest in this thread then I think these would be some good tests to run. If there isn't much interest then I won't do the tests because of the time and money I would need to invest. I would also probably write up a formal report as well (a very time consuming process)
 
Lets see what happens! Hopefully this is well received. So what kind of wires should I try and obtain? Different types of insulators could be useful as well.
 
Peace,
 
Blair
 
P.S. If you think I'm missing some type of quantitative measurement then mention it.
 
P.P.S. Don't bash me because I'm trying to research something.
 
P.P.P.S. I'm not trying to ruin the cable market, if you hear a difference, thats all that matters. If it's a placebo effect or a real effect choose whatever makes you happy. I'm not telling you what you should do here. I'm just trying to put some quantitative measurements on the table for people to reference if they'd like to.

 

[kingtz]

I, for one, am very interested to hear of your findings. I wish you the best of luck and eagerly wait to hear your report!

 

[Uncle Erik]

I'm very interested in your tests, as well. You might want to look back a little and read Nick Charles' tests which were similar. Maybe pick a few things he didn't try. Also, you might want to take a look at the various power cables, too.

 

[Roger Strummer]

Add me in the very interested group of people. Heck if you want help with the reports or anything I can help you gladly, just tell me. Even more if you want to post the graphs and results online (besides the formal report which I'm supposing would be a pdf paper) I'm your man.

 

[dexter3d]

Quote:

Here's what I plan on doing for the test...
 
The measurements I'll be taking will be frequency magnitude/phase response and THD from 5Hz to 40KHz using an ATS-2 audio measurement system. I'll measure all three of the following voltages: 5Vrms, 1Vrms and 10mVrms. The source impedance will be 20 ohms and 50 ohms as well if I can time.

 
That's a terrific idea! However, based on my experience, I am 99% sure that the outcome of your test, whatever it will be, is not going to convince believers to change their mind. After you publish your findings, you will get a smoke-screen of unfalsifiable pseudo-counterarguments ('You can't measure it', 'but you didn't test my alpha-centauri cable', etc). But anyway, compulsory education is not our business, and this won't diminish the value of your research

 

[Pio2001]

Good luck with your project. I myself did the same with some cables.
 
The only significant parameter was got with a very special cable. A DIY CAT network cable setup according to an audiophile trick. Basically, half of the conductors were assigned to the + and the other half to the -, and all of them were entangled together in the cable, maximizing lineic capacity.
The cable was used as a speaker cable with electrostatic speakers, whose impedance was as low as 1 Ohm at some frequencies.
At the end, the user managed to get a loss of more than one dB in high frequencies just because of the cable.
 
The idea is that the spectral response of a cable is conditionned by the impedance of the load. For speaker cables, you should measure with a complex load, with variable resistance and reactance according to the frequency.
 
Beware of measurements made on very low impedance sources (speaker outputs). A short-circuit instantly destroys the source. And short circuits have an uncanny ability to multiply themselves when a low impedance source is close (Murphy's law).
 
On interconnects, the measurement that will reveal most differences is a the spectrum of the background noise. Each cable will pick a different background noise. Even the same cable placed differently.
 
In the measurements that you plan to perform, I got a significant difference with 5 meters interconnects : frequency response down 0.02 dB at 20 kHz. Measured with RMAA thanks to a signal consisting of a sum of sines across all the audible spectrum.
 
Don't measure frequency response with white noise or pink noise. This have been done already by a distributor who wanted to prove that stands had an effect on CD players. All you get is measurement noise, and people can't help analysing the noise itself in order to find differences.

 

[brconner]

 
Quote:

 
That's a terrific idea! However, based on my experience, I am 99% sure that the outcome of your test, whatever it will be, is not going to convince believers to change their mind. After you publish your findings, you will get a smoke-screen of unfalsifiable pseudo-counterarguments ('You can't measure it', 'but you didn't test my alpha-centauri cable', etc). But anyway, compulsory education is not our business, and this won't diminish the value of your research

I wouldn't be surprised at all. I'm honestly expecting that to happen, and it's okay. Like I said before, people can believe what they want to. I'm not trying to change peoples opinion, just trying to put something quantitative people can look up if they're interested. 

 
Quote:

I'm very interested in your tests, as well. You might want to look back a little and read Nick Charles' tests which were similar. Maybe pick a few things he didn't try. Also, you might want to take a look at the various power cables, too.

I'll definitely try to find his tests! Do you have a link or anything? Power cables could be a little tricky to test, but I'll see if I can come up with something. The main issue is that power from the wall socket is incredibly varied from location to location. For example, in one house it may be that perfect 120Vrms sine wave, while in another it could be 110Vrms with a ton of noise in the sine wave. Like I said though I'll try and come up with some ideas.
 
Quote:

Add me in the very interested group of people. Heck if you want help with the reports or anything I can help you gladly, just tell me. Even more if you want to post the graphs and results online (besides the formal report which I'm supposing would be a pdf paper) I'm your man.

 
Thanks! I'll definitely let you know if I need some help.
 
This is great, it looks like there's some interest in this experiment!
 

 

[grokit]

Subscribed...

 

[brconner]

Pio2001,

The test equipment actually handles all of the source impedances and such. It's really an awesome piece of equipment. I'll definitely be careful though. Don't wanna break the test equipment! I'd owe someone a lot of money lol.

Also, I like the idea of testing the cat cable, I'll definitely try that.

 

[Currawong]

Maybe also include plugs made and/or coated with different metals as well. 

 

[nick_charles]

Quote:

I'll definitely try to find his tests! Do you have a link or anything?  
  

 

http://www.head-fi.org/forum/thread/405217/my-cable-test-enterprise

 

[JB197]

Go for it !
I'll be following you all the way.

 

[brconner]

Thanks! I'm reading through it now.

 

[brconner]

Quote:

Maybe also include plugs made and/or coated with different metals as well. 

I'd love to test the actual plugs and stuff, but that would get very expensive very quickly. I'll look into it though.

 

[brconner]

So after reading a significant portion of the thread that I'd like to make something very clear. This is only to test the wire. Not the source or the destination. The great thing about dB is you can just add them and subtract them. Seriously its like the coolest thing ever, waaaay better than trying to compare things in volts haha. 
 
Also I just realized that it was Nick Charles himself who gave me the link, thanks! I think its a bummer how that thread turned into a flame war. Hopefully that doesn't happen in this one. You did a great job with analyzing the data, I think.
 
So again, the test I'm going to perform will only going to show the difference that the wire itself makes.