from the article:
The important thing to notice is the y-axis:
Obviously spent years in the lab figuring that one out.
The important thing to notice is the y-axis:
Obviously spent years in the lab figuring that one out.
I built up a 1.2m length of star quad using 4 lengths of 1mm² stranded cord.
The capacitance after twisting was ~150pF/m
The 250mm length inside my amplifier has ~37pF of capacitance loading the amplifier output.
A 600mm length outside the amplifier adds ~89pF and then there is some from connections.
Short cable gives low capacitance.
An active speaker that omits the external length will be even better.
The capacitance after twisting was ~150pF/m
The 250mm length inside my amplifier has ~37pF of capacitance loading the amplifier output.
A 600mm length outside the amplifier adds ~89pF and then there is some from connections.
Short cable gives low capacitance.
An active speaker that omits the external length will be even better.
I once measured the RF characteristic impedance of a cheap speaker cable, as I wanted to use it for RF purposes. I seem to recall it was about 80 ohms. It would have had a velocity factor around 0.8 (a guess) so capacitance would be around 52pF/m. Hence I can estimate that the 'normal' range for speaker cable will be maybe 40pF/m up to around 200pF/m.eriksquires said:
Well, my comments are informed by 5 decade of experience with both the technical and actual experience with actual usage, and you've rejected that. Probably my experience doesn't agree with your prejudices, so you call it all invalid.
There is no way that any measurement causes phase shift. The measurement characterizes the phase shift, but does not cause it.
The subjective part you don't apparently don't want to hear is that the phase shift in most speaker cables is not audible. This is reinforced by the actual measurement result which shows a maximum of 1/4 of a degree at 20 KHz.
That is a ludicrously small amount of phase shift - equal to the phase shift in in sound travelling through a negligible amount of air. For openers the wavelength of sound @ 20 KHz is only a fraction (about 2 thirds) of an inch for 360 degrees of phase shift. A quarter of a degree of phase shift is on the order of 1/1520th of that 2/3rd of an inch.
So rotsa ruck with that 1/2,000th of an inch distance matching.
That's not the problem. You appear to be asking for answers that reinforce your prejudices and have destructively ignored the relevant, experience-based answers which appear to be telling you what you don't want to hear.
The last time I did any cable experiments was about 16 years ago. I remember the executive summary, but not the details. But since you've rejected the executive summary, it just isn't worth my trouble to go any further.
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RE testing cables- The woofer tester is not really appropriate for cables. its not sensitive or resolving enough to measure the resistance (milliOhms, 1/1000 of its nominal range) or pF or uH. Any results would be questionable at best, either measured directly or with a resistive load.
The lumped values can be measured pretty easily with the appropriate instruments, but they are specialized devices. Probably more relevant would be to measure the composite system including the amp and a variety of speakers. A network analyzer would be the best tool. An HP3577a 3577A Network Analyzer [Obsolete] | Keysight (Agilent) or an Omicron Bode 100 https://www.omicron-lab.com/bode-100/product-description.html are good examples. You can see the change in amplitude and phase vs. frequency for different cables and no cable. Again you will need to remove the effects of the amp itself to the phase and gain but a modern instrument usually has provisions for doing that.
The remaining question is whether the changes are audible. These intruments are very sensitive. I believe that John Atkinson did measure some differences with different cables a long time ago that were at the accepted threshold of audibility. However he never went further with it.
The lumped values can be measured pretty easily with the appropriate instruments, but they are specialized devices. Probably more relevant would be to measure the composite system including the amp and a variety of speakers. A network analyzer would be the best tool. An HP3577a 3577A Network Analyzer [Obsolete] | Keysight (Agilent) or an Omicron Bode 100 https://www.omicron-lab.com/bode-100/product-description.html are good examples. You can see the change in amplitude and phase vs. frequency for different cables and no cable. Again you will need to remove the effects of the amp itself to the phase and gain but a modern instrument usually has provisions for doing that.
The remaining question is whether the changes are audible. These intruments are very sensitive. I believe that John Atkinson did measure some differences with different cables a long time ago that were at the accepted threshold of audibility. However he never went further with it.
My friend who has been in the audio business for more than 40 years - from starting a single store that grew into a large chain, to now owning a speaker company that's bin in business more than 30 years, has read basically every book about psychoacoustics, speaker design and measurement, and most relevant research papers said that he has never once found a scientifically valid study/published experiment showing significant audibility of different types of speaker cables so long as they had sufficiently low resistance to not differently impact the amplifier's output to the speaker. He acknowledged that there were some cases where the speaker wire being used had sufficiently high resistance to slightly alter the FR of the speaker.
In all cases where resistance was a relative non-issue, "lamp cord" has never been demonstrated to be inferior to even the most expensive (or claimed "best") speaker cables in double blind tests (which are the only valid way to evaluate such things honestly).
In all cases where resistance was a relative non-issue, "lamp cord" has never been demonstrated to be inferior to even the most expensive (or claimed "best") speaker cables in double blind tests (which are the only valid way to evaluate such things honestly).
I ran an experiment with speakers and amps I no longer have. I used a pair of Focal Profile 918's and a pair Yamaha P2100's in dual-stereo mode. The pre-amp was a Theta Casanova being fed digital from a Logitech squeezebox. The extra channels were used for surround, when watching movies. Otherwise the amps were effectively dual-mono with an unused channel.
In a single-blind test with Jazz loving non-audiophiles I could easily demonstrate the difference between Wireworld Equinox 6 and Mogami Sound Runner, which was effectively finely stranded bare copper.
To each of the blinded listeners the differences in treble and imaging was consistent. What was not was the "value". When asked open ended questions about imaging and treble response, they came to the same conclusions that I did. The WW imaged better, but Mogami had better treble. My friends unanimously prefered the Mogami.
I labeled the cables "before" and one the "after." no names, or prices were discussed and they could not tell which cable was hooked up by looking. Nor did I say "this is what I normally use."
For me, the value was in imaging. For the non-audiophiles, they preferred treble response. Based on this I have concluded for myself that in this situation there was in fact a difference in cables. What I cannot do for myself or anyone else is conclude that it's worth anything. Much more importantly for me to understand from this is to try to get a grip, in numerical terms, where "Imaging" lies, because what I really want is not to spend $20,000 on cables masquerading as tone controls. For us to be doing that in the 21st century is obscene. What I want is to have a receiver I can press a button and say "more imaging please" or "more air."
I further have concluded from this that most of the so-called scientists and engineers in the business and boards are nothing more than historians guarding dusty old books who have not advanced our collective understanding further so that anyone can have more imaging, warmer, less detail, more detail, what have you by pressing a button on an app. When anyone starts working towards that instead of quoting papers from 30 years ago to explain why I am making stuff up, that person I'll call a scientist.
Best,
Erik
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Well, it's not hard to know that, when considering a group of cables which all have relatively low resistance, that the effect on the signal is *quite* small compared to many other more significant factors - such as, the speakers themselves, and the room, and the source material.
I suggest that there are many far more meaningful areas that can be addressed in your speakers than the cabling - some inexpensive, and some not so inexpensive.
If you have stand mount "bookshelf" speakers for instance, addressing the floor bounce cancellation has far more significance than which speaker cables you use.
How you deal with the back wave of the drivers. Panel resonances in your speaker enclosure. Time alignment of the tweeter and the mid/woofer. Power response vs frequency response....
All those items have a significantly larger impact - both subjectively in listening tests and in objective measurements.
Most certainly, the difference between any two different models of speakers, will be far greater than the difference between any two sets of reasonable speaker cables, don't you think?
I suggest that there are many far more meaningful areas that can be addressed in your speakers than the cabling - some inexpensive, and some not so inexpensive.
If you have stand mount "bookshelf" speakers for instance, addressing the floor bounce cancellation has far more significance than which speaker cables you use.
How you deal with the back wave of the drivers. Panel resonances in your speaker enclosure. Time alignment of the tweeter and the mid/woofer. Power response vs frequency response....
All those items have a significantly larger impact - both subjectively in listening tests and in objective measurements.
Most certainly, the difference between any two different models of speakers, will be far greater than the difference between any two sets of reasonable speaker cables, don't you think?
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Wireworld Equinox 6 is an extreme example of a low resistance, high inductance cable, so not exactly a shock that it affects the treble.
A subtle tone control would be much cheaper
A subtle tone control would be much cheaper
This paragraph says so much, this is the view of a serious audiophile... and such a close minded and stupid view... who develops audio equipotential, Joe Bloggs Super Tweaker. nope engineers and scientist
I'll leave it to others to question how rigorously your test was run.
No questioning needed - he said outright that it was a single blind evaluation.
Single blind evaluations have been known to be highly prone towards being invalid since 1907 and the days of Clever Hans the talking horse:
https://en.wikipedia.org/wiki/Observer-expectancy_effect
https://en.wikipedia.org/wiki/Clever_Hans
Of course you have reached these deprecating conclusions about everybody who disagrees with you. They would appear to be important to your feelings of self-worth.
Reality is that most of the basic principles of electronics that apply to interconnects and speaker cables have been well-known for close to 100 years, or longer. So, you're about 70 years off in your false claims about the time line of the relevant science, as well.
If you wish to be convincing, please do try to get your relevant facts right. ;-)
Otherwise, many will be perfectly happy to let you wander in the weedy fields of pseudo science.
You were testing how well behaved, or how badly behaved, the amplifier was when presented with a reactive load.
The cables themselves had no sound.
It's their reactive parameters that change the signal fed into the speaker.
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