No need. Just use a Wheatstone bridge. You could even use a speaker in the center of the bridge to "hear" any difference. That is basically the test I proposed to the James Randi institute a few years ago. It was rejected.
You'll want to be sure that the cables have the same LRC values, or there will be a difference.
I read the Wiki entry for Wheatstone bridge (Wheatstone bridge - Wikipedia, the free encyclopedia) but I'm unsure how it is applicable for detecting audio differences between cables carrying an AC voltage. Could you elaborate or provide a link?
I don't think it will be that easy. The differences between similar cables are mostly in detail and stage focus. Stage focus, according to my logic, must be influenced by small phase errors between channels, our ears are very sensitive to this. When you create an error signal, this small phase errors will be converted to even smaller voltages with no perceivable correlation to the music. Even if you hear a very small 'noise' signal, how will you be able to know what effect that had on the music? Apart from that, all the extra processing may just as well cancel the differences you can expect similar cables to have on a system.
Ok, if I understand you correctly you are talking about stereo signals and phase differences between them. That’s fine, its perfectly achievable to convert stereo signals. Any phase difference between the channels will be correctly encoded as an interleaved data stream, without loss of information. The stereo difference signal will show any differences concerning phase between the two cables, to the limit of 24 bits of information, which is everything possible in the audio signal.
If you don’t hear anything when listening to the difference signal, then there is no audible difference (by definition). If you do hear the difference signal (above the noise floor of the equipment) then all we can say is there is an audible difference between cables. It’s then a somewhat harder question about which cable sounds better. That leads into criteria for judging what is the best sound, a whole new ball game.
The processing won’t cancel any differences. If there are differences the difference signal will have them, the mathematics guarantees it.
Overall, the point of the procedure is to potentially save you money: if there is no difference between cheap cable and the expensive stuff, then don’t buy the expensive stuff.
Well that you can only guarantee if the recording process is perfect, which we all know is not possible.
An easier method to "potentially save money" is to listen to both cables on your system with your favourite music, if there is no difference, buy the cheap cable. 😀
The Wheatstone Bridge of cable testing...
There's a problem, however...those -140dB converters probably use a brick-wall filter at 22 or 44kHz -- one of the issues with cables is that they are antenna for RFI and EMI -- while you (most of us, certainly) can't hear in the range above 20kHz every PN junction does hear it -- you can most certainly see this with a low noise preamp like Denis Colin's "Low Noise Measurement Preamp" when you look at the amplified signal before the A-Wtd filter.
If cables didn't make a difference, Hewlett Packard would have just used a piece of coax to connect the ovenized frequency reference to the external oscillator input of their low-noise measurement receivers, instead they use this gizmo:
An externally hosted image should be here but it was not working when we last tested it.
Very interesting, Jack. It would be good to know what that RF might be doing to the feedback loop of power amps or the inputs and outputs of line level gear.
Waaaayyy back in this thread there was a link to the multi-tone tests done by Cerwin-Vega. The also noticed a lot of RF on the speaker cables. And they noted that it changed by time of day.
Even easier is to just buy the cheaper (of good engineering quality) cable and relax, knowing you have not been suckered.
Fredex,
You are right most of the time as people fret to much about cabling. I think that most people could care less about cabling. I happen to be one of those anal types that has been exposed to great audio for too many years and will not settle for less than the best in my system, but that does not mean the most expensive either. I buy what I can justify sonically and price wise. Most people don't want to think about cabling in their systems and that is great for them. Enjoy your music and don't fret it. I think that you have a good approach to it.
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That's why i'm making cables now, i see SO MANY places charging rediculis amounts of money for nice cables, some being cheap crap too.!
I'm in the process of making a site and cables, ( just made 3 sets ) selling them at cost, gives me something to do.
100$ for a set of nice speaker cables ? sounds fair, compared to others that cost 200-20k$
Well I just think you cannot dismiss good engineering, it works. In my book good engineering is not about 'over engineering' it is not wasteful of time or resources. A $7k set of cables is not good engineering unless it is the only way of getting a certain result.
But if you include the human factor you could say that only by spending $7k can you get the desired result, which is having the audiophile feel good about his or her system. I'll concede it is good for the economy. 🙂
Sounds fair. Wouldn't hurt to make them attractive or high tech looking. Either a lot thicker or a lot thinner than the competion. You never know it may have a tiny affect on sales. 🙄
I was not slamming the engineering, just stating what I feel is true. Most people just don't care about cables 🙂
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Mine are attractive, well they are also hand made too, the purpose is to sell cables to people pay for the supply and have fun.
takes me about 3 hours to make a set of cables from start to finnish. I take my time plan out each set one at a time, go over them make sure they are correct, Apearance too, because if you miss a weave it changes the look. I will post pictures of the more if ppl are interested.
if you don't weave them properly they wont turn out proper, the colors are pretty also. I have a assortments of colors on the way.
Profit, well if any it goes back into buying more products to make more cables, its a hobby 🙂 its fun and keeps me occupied for the time being. Soo ill be able to take orders of colors that people wish, also i'll be offering banana plus or spades in any configuration.
Colors available are, Blue Red White Black Green Orange, i can offer single colors or match colors in 2.
My favorite are orange and white, or white and Red.
J'
An externally hosted image should be here but it was not working when we last tested it.
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jleaman
They look good. I believe weaving is good for the soul too. Good luck with your venture.
They look good. I believe weaving is good for the soul too. Good luck with your venture.
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Joined 2002
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