Ha ha "dropped the ball on gravity"
The Science of Cables
It seems to me that there is too little scientific, objective evidence for why cables sound the way they do. When I see discussions on cables, physical attributes are discussed; things like shielding, gauge, material, geometry, etc. and rarely are things like resistance, impedance, inductance, capacitance, etc. Why is this? Why aren’t cables discussed in terms of physical measurements very often?
Seems to me like that would increase the customer base. I know several “objectivist” that won’t accept any of your claims unless you have measurements and blind tests. If there were measurements that correlated to what you hear, I think more people would be interested in cables.
I know cables are often system dependent but there are still many generalizations that can be made.
Seems to me like that would increase the customer base. I know several “objectivist” that won’t accept any of your claims unless you have measurements and blind tests. If there were measurements that correlated to what you hear, I think more people would be interested in cables.
I know cables are often system dependent but there are still many generalizations that can be made.
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I don’t want to bring anybody down but John Archibald Wheeler, Charles Misner and Kip Thorne wrote the book on gravity... a long time ago. Almost 50 years ago, actually. My, how time flies! Let’s just say gravity is not what you probably think it is but what it is is probably understandable to most people who aren’t English majors or audio engineers. 😀 I’m afraid you’ll have to look elsewhere for something that’s still a mystery. |
I have heard subtle differences between how different speaker cables sound in an A-B demonstration at an audio club and the difference was above a threshold of placebo effect. Interconnect cables can sound different if capacitance is not accounted for in their design and the context of input impedance. However, there is some bad physics adduced in the marketing of very expensive cables. Here are two examples. The first is skin effect, the concentration of current towards the surface
of a conductor as the frequency of alternating current increases. There
are some speaker cables which endeavor to address skin effect in their
design: either by making ribbon cables which are thinner than skin depth
at higher audio frequencies or by litz wires which bundle insulated
individual strands of wire which individually are thinner than skin
depth. But nobody has made any calculations to determine whether such
designs make a difference in whether anyone could hear treble roll-off
caused by the skin effect in a speaker cable. So let us consider a set
of 5 foot long cables of 8 gauge copper wire connected to a pair of
speakers with 4 Ohms impedance. The total of 10 feet the audio signal
must pass through the two 5 foot speaker cables has a DC resistance of
only about 0.006 Ohms. At 20 kHz, skin effect concentrates the current
towards the surface of the cable reducing the cross-sectional area which
carries the current and the resistance increases to 0.012 Ohms. Compare
that to the 4 Ohms speaker resistance in the case of a magnetic planar
speaker which has negligible inductive or capacitive reactance and the
effect is slightly over one one hundredth of a decibel roll-off at a
frequency almost nobody can hear. Either the cable designer has too
shallow an understanding of skin depth to calculate this or they know
the effect is inconsequential but choose to capitalize upon their target
audience's superficial understanding when they advertise how they are
doing something about the skin depth problem which does not really
exist. Another questionable matter is the alleged grain structure of
copper wire emulating semiconductors at the interfaces between grains
making the resistance non-linear with respect to applied voltage at low
signal. Nowhere in any graduate school physics or electrical engineering
texts is there a non-zero derivative of resistance with respect to
voltage or current in Ohm's law for copper wire and if this law applied
to low signal voltages antenna cables from a receiving antenna atop a
tall tower to an FM tuner would have nonlinearities which would generate
Fourier RF harmonics that would disrupt any frequency of a radio
station inducing only micro-Volts in the antenna. Another issue is
slight nonlinearities in the dielectric which insulates cables. This
becomes insignificant at the few volts in a speaker cable and an
interconnect cable not suffering an electric field which makes the
alignment of dipole molecules change the dielectric constant at much
higher voltages. Also since the electric field in a cable is parallel to
the cable in a conductor, there will be no component of electric field
in the insulator.
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drbarney118 posts02-16-2019 4:19pmI have heard subtle differences between how different speaker cables sound in an A-B demonstration at an audio club and the difference was above a threshold of placebo effect >>>>A threshold of placebo effect? Whoa! I did not know that. |
Thank-you taras22. As for eric_squires all I get from you is an appearance of personal jealousy. Dismissing a detailed argument as irrelevant shows no analytic skill and is a lazy thinker's way of trying to dominate a conversation. You have been well and truly one-upped and the more you complain, the worse you look. |
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