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Physical/scientific aspects behind cable sound. Discuss. - Page 3

post #31 of 87
There are skeptics who think that just because we can't hear RFI it doesn't make a difference to the audio system. It's the same thing with power and vibration. They think that as long as sound comes out from the speakers, it can't sound any better.

Then there are other skeptics who sit where with their measurement devices and say "it's impossible for humans to hear these differences, they are too small!".

Then there are others who measure frequency response of speakers with crappy microphone. For some reason they think more "bass information" means "louder bass". They don't actually own an audio system other than a single speaker. Harvester test

Then there are others who sit there eating food and whisky swirling while chatting to friends, then they laugh and say "I don't hear a difference, hahaha, stupid audiophiles."


If the difference is subtle, you aren't going to hear a difference if you aren't interested in hearing a difference. The more obsessed you are, the bigger the differences will be.
post #32 of 87
I'm an engineer (dealing mostly with vibration and shock analysis) and we use different types of highly sensitive accelerometers for analysis. All of the accelerometers use coaxial cables, but certain types require a specific type of coaxial cable construction. Using a normal coaxial cable will give noise, pretiggers, and just inaccurate data. The difference between cables has to do with the type of shielding and dielectric used.

So in my field of engineering, cables do make a difference. Take that for what its worth and make your own conclusions
post #33 of 87
Quote:
Originally Posted by pageman99 View Post
The differences between copper and silver conductance might be miniscule, billionths of a second, picofarads, etc., but remember we ain't sticking the end of the cable directly into our ears!

The signal goes through various manipulations in the amp end and these miniscule differences get multiplied millions or billions of times by the op amps, caps, resistors, transformers, transducers etc. etc..

So tiny differences between cables can and do get multiplied in the process as well, to the extent that human ears can hear differences.

Remember we're reading bits and bytes, or the tiniest of vibrations at the source. AND this source material is on the same scale of the electrical differences between cable material and construction. It's that simple.

I don't know what's so difficult about that concept. That's all. 8-)
I think you may be overestimating how much amplifiers do. My Interconnects carry a 2v signal and my amp outputs 5w @ 8 ohm (~6.3v?). Although I must admit that I dont fully understand it all and I just did an approximation there, I cant see how my amp would be multiplying the differences in cables by millions or billions of times
post #34 of 87
Quote:
Originally Posted by pageman99 View Post
It's simply a matter of scale. The cables work on the same scale as the signals transmitted through them . . .
This is a very odd statement. What are you trying to say in more formal terms?
post #35 of 87
Quote:
Originally Posted by yo2tup2 View Post
I'm an engineer (dealing mostly with vibration and shock analysis) and we use different types of highly sensitive accelerometers for analysis. All of the accelerometers use coaxial cables, but certain types require a specific type of coaxial cable construction. Using a normal coaxial cable will give noise, pretiggers, and just inaccurate data. The difference between cables has to do with the type of shielding and dielectric used.

So in my field of engineering, cables do make a difference. Take that for what its worth and make your own conclusions
Noone is doubting that different grade of cables make large differences in certain areas. The difference is that the different grades of cables used in industrial applications measure better -- the lesser grade fails while the higher grade passes.

A lot of the cable voodoo centers around the fact that, according to those who hear a difference, we cannot measure (except with our ears) the differences between cables.
post #36 of 87
well for those of you who know about how capacitors work, the dielectric material used has something called soakage. try charging an electrolytic capacitor, and then completely discharge it (should read zero on multimeter). then wait 1 hour. put the leads of the capacitor on your tongue. zap! guess what there is a voltage again as if by magic! it is the dielectric material itself that holds charge and slowly lets it creep back into the metal that makes up the capacitor. cables work the same way. the plastic around the cable holds charge and lets it creep back slowly, thereby "smearing" the sound. this can be measured using certain expensive equipment not available to ameteurs like ourselves. using teflon instead of the typical plastics around the wire helps, because teflon has a lower dielectric constant. air or vacuum would be best, but is not practical since bare wires have a tendency to short.

of course RLC is also a factor, but according to the math the effects on the frequency response under 20kHz are not that great. anyway, bring on a blind interconnect test, i should be able to pass it very easily. i will request that i provide my own cables and test track of course.
post #37 of 87
Thread Starter 
Quote:
Originally Posted by Chu View Post
Noone is doubting that different grade of cables make large differences in certain areas. The difference is that the different grades of cables used in industrial applications measure better -- the lesser grade fails while the higher grade passes.

A lot of the cable voodoo centers around the fact that, according to those who hear a difference, we cannot measure (except with our ears) the differences between cables.
I'll also add that in research labs I've been in, cable shielding is important. Can't tell you how many times I've picked up noise on my scope just holding the other end of a probe and acting as a human antenna.

But I've never seen cables used in the labs that have been made of exotic metal conductors. Either our research funding doesn't allow it, or there isn't a need for them, at least in our field of research.
post #38 of 87
Quality of materials makes a difference but I see these reviews of $20000 speakers with $700 Speaker wires when in reality a shielded coat hanger could deliver an almost identical signal. Even some of the monster cable stuff is overpriced IMO. Everything product they sell they mark up more than 400% from what it costs to make which kind of bothers me. I went from temporary 22 gauge wires on my Polks to 14 gauge shielded, oxygen free, and terminated monster cables and I dont hear a difference. I think the biggest jump you will see in quality of a cable is going from a $15 component video cable to a $100 one. Video seems to be more demanding than audio.

Also A power cable is only as good as what your power source allows. So if you have finicky AC I don't think a $100+ power cord will make much of a difference.
post #39 of 87
Quote:
Originally Posted by Patrick82 View Post
If the difference is subtle, you aren't going to hear a difference if you aren't interested in hearing a difference. The more obsessed you are, the bigger the differences will be.
You have a point there, I asked my father to listen to my HD650 and D2000 to see which he liked the best, the answer: I didn't really hear a difference He He!
post #40 of 87
Quote:
Originally Posted by Chu View Post
Noone is doubting that different grade of cables make large differences in certain areas. The difference is that the different grades of cables used in industrial applications measure better -- the lesser grade fails while the higher grade passes.

A lot of the cable voodoo centers around the fact that, according to those who hear a difference, we cannot measure (except with our ears) the differences between cables.
In my use, its not about higher grade vs. lesser grade. All of the cables we use are high grade and are all shielded, the difference has to do with the build construction of the cables (note that I didn't say material).
post #41 of 87
Quote:
Originally Posted by pageman99 View Post
Which is why those with the best equipment (distorts less) seem to be the ones that seem to hear the biggest difference between cables.

Kinda makes those "cable makes a difference" folks point, if you ask me.
The interesting thing is according to the Golden Ears at Stereophile, Cary 300SEI sounded better than a Bystrom (Cheever Paper Pg. 2). The Cary has almost 5% distortion and the Bystron is orders of magnitude better.

On p. 38 of the paper, by using certain pattern (described in the paper), a series of eight haromonics is sent out and yet only a single tone is perceived by the human ears.

Does this means the "low distortion" don't matters? Or maybe it's the distortion we are hearing that we are perceiving as quality.

Bob Carver tweaked a $600 amplifier to match a $12,000 amplifier in the 80s (electrically). The Stereophile guys basically can't tell the difference with their own music in their own environment.

Of course this is only amplifier related. It is obvious that I can make a cable sounds different by adding a bunch of inductor and capacitor. But if I clone a $10 cable to measure exactly like a $1000 cable in terms of RLC, will that still makes a difference?
post #42 of 87
Thread Starter 
Just a reminder, RLC characteristics are important transmission line measurements (you sure aren't going to measure 75 ohms across a cable with an ohmmeter). The question is, are audio interconnects considered 'transmission lines' in the EM sense?

I'll quote Bill Whitlock in his transmission line article (that you can find on google pretty easily) since he does a very good job of setting up what a transmission line is http://digitalcontentproducer.com/ma...ion_lines_why/

Quote:
What is a transmission line, anyway? There are broad definitions, such as "the conductive connections between system elements which carry signal power" (ANSI/IEEE Std 100-1977 Dictionary of Electrical and Electronic Terms, page 739), under which every cable becomes a transmission line. Most engineers, myself included, would narrow the definition considerably. The following is the most concise, accurate and simple definition I have encountered: "A transmission line consists of an arrangement of electrical conductors by means of which electromagnetic energy is conveyed, over distances comparable with the wavelength of the electromagnetic waves, from one place to another. Transmission lines differ from simple electrical networks in that their inductance, capacitance, and resistance are not lumped but are distributed over distances such that the time required for electrical energy to travel from one part to another has to be taken into account. A uniform transmission line has what is called a `characteristic impedance'. This is the impedance that would be measured at the end of such a line if it were infinitely long. The importance of this characteristic impedance lies in the fact that if any length of line is terminated in an impedance of this value, then all the energy flowing along the line is absorbed at the termination and none is reflected back along the line." (Radiotron Designer's Handbook, F. Langford-Smith, Amalgamated Wireless Valve Company, Sydney, 1953, pages 890-891.)
The second definition is what is important to us. Is an audio cable a transmission line in that sense?

For that purpose, I'll point you to another very well written (read easy to understand) article on transmission line effects and why they exist: http://www.allaboutcircuits.com/vol_2/chpt_14/1.html

Transmission line effects arise from the fact that signals propagate through a line at close to the speed of light. For short lines, this is for all intents and purpose, instantaneous. For longer lines, a wave does not propagate to the end instantaneously. As electrons start to 'move,' you get an electric field forming between the two conductors due to an imbalance of charge. This contributes to the capacitance of a line. Once current starts to flow, you get the formation of a magnetic field and hence your line has inductance. What you get is kind of like the phenomenon you get at a stop light turned green where not all the cars move at once and you have a delay between when the first car starts moving and when the last car finally gets going.

The key points to glean from the last link (if you read through all the succesive chapters) is that in order for transmission line effects to become significant, the wavelength of signal you are transmitting is typically on the order of 10% the total length of the line you are transmitting it through. What does this mean? A signal at 10-20kHz would have to travel on a line that is miles long in order for effects to become significant (keep in mind the speed of light, and the distance of the cable.)

Now what about a coaxial cable? They're so short. What's up with that? In this case, coaxial cables typically handle video signals comprised of frequencies in the millions of hertz. This means the wavelength of a signal at that frequency is significantly smaller than that of a signal in the audio frequency range and the cable does not have be as long in order for wave propagation times to become significant.

The question is, are these differences significant enough to hear at audio frequencies?

edit: The same reasoning applies to power cables. Assuming a cable is well shielded, transmission line effects should be negligible as well. You've got an incredibly short cable carrying what is a very low frequency (60 hertz) signal. Resistance is almost zero for a cable run of that length and ample conductor gauge. What else can a high end power cable improve on?
post #43 of 87
Excellent point on the transmission line impedance, however, other than line impedance there is also the DC value.

For example, the RLC value will continue to increase with longer cable length, this changes the bandwidth of the cable. For high frequency this could detrimental. Therefore a way to compensate this is to provide proper equalization if the length is not deterministic. One problem remain; how to do you tell what is the cable length and provide the proper compensation. The normal way is to detect the amplititude and give the proper compensation. This is known as adaptive equalization. This is commonly used in 10/100/1000 Ethernet network.

Another method is to provide simulated loss. The receiver will assume a worst case loss and provide worst case compensation. The transmitter will then provide the additional loss. This is called line buildout. This is commonly used in telecommunication network.

Now for testing in the lab where you don't want to stock miles of cable and taps. You can buy or build "line emulator" to simulate the target cable used. So most cables can be modeled and emulated regardless of material used.

For detail, please google Ethernet PHY adaptive equalizer, line buildout and line emulators.

There is very little magic in the cable. The curiosity is why some people claim to hear the difference while others don't. IMHO, cable is well understood but we still got a long way to go on perception.

In my experience, I have heard difference between cables (even in the same brand) but they can all be accounted for some by a physical/measurable difference.
post #44 of 87
Something I always found interesting while reading feedback regarding the more expensive cables on forums... I never read of anyone that has tried any of the more expensive cables (ie Virtual Dynamics cables, PAD, JPS Aluminta, and other $1000+ cables) say that they've tried them and didn't hear any differences whatsoever. There are plenty of feedback were people say they've tried these cables but hated the way they sounded, so they went to different cables (sometimes much less expensive cables)....but I've never read of anyone say they tried them and didn't hear any differences at all.

i'm curious....for the "non-believers" and people that say don't hear a difference between cables.... what cables have you tried and compared? or are your conclusions based purely on the lack of measurements that show differences?

this question is just for my curiosity, not for debate purposes :P
post #45 of 87
Non-believers are not going to spend $1000 just to to prove they can't tell the difference.

Personally I'm not going to spend $1000 on a cable to find out if there is a difference. I got bills to pay, a kid to put through school and a car to gas up.

I have heard my friend's garden hose system. (he's very wealthy and have a $250K system). He's got money to burn and I enjoyed the music so why talk about cables.

But I think we are going off a tangent discussing what cable you have compared to with this thread. This thread is about facts and theory.

I have heard difference between cables. Once it's caused by the connectors are over crimped and cause leakage between two channels. The other was was caused by dirty connector. The most expensive cable I owned are Monster and some Audioquest.
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