rdf said:
Yeah, I'm sure that would show much bigger variations. But I've been trying to sneak by with using what models are available. Model development is very time-consuming, and I generally only do it for projects I'm working on that can use the models.
It would be really interesting to see the results of such an analysis though.
Andy, thanks for the AudioHolics cable measurement links. Remind me to stay clear of that Goertz cable, ~350pF per foot!
More than 6 years and 4000 posts later, still the same blah, blah.
And yet not long ago Andre Visser posted a link to a very interesting study that showed - measured! -differences between cables. Not only cables, but different types of loads and amp.
Look back at post #
3671.
To me, at least, the is is a very interesting study. Real amps, real cables, real loads. Different loads. Yes, they measure differently on real speakers than on resistors.
But there was scant mention or discussion of the test that Andre linked to. Maybe3 or 4 replies. (Alex was the only one to dig the test.)
Why? Are we more interested in arguing about the subject than the subject itself? More interested in proving the other side wrong than in the subject itself? That's the only conclusion I can draw.
Sorry to harsh your buzz, boys. Now back to the bickering....
And yet not long ago Andre Visser posted a link to a very interesting study that showed - measured! -differences between cables. Not only cables, but different types of loads and amp.
Look back at post #
3671.
To me, at least, the is is a very interesting study. Real amps, real cables, real loads. Different loads. Yes, they measure differently on real speakers than on resistors.
But there was scant mention or discussion of the test that Andre linked to. Maybe3 or 4 replies. (Alex was the only one to dig the test.)
Why? Are we more interested in arguing about the subject than the subject itself? More interested in proving the other side wrong than in the subject itself? That's the only conclusion I can draw.
Sorry to harsh your buzz, boys. Now back to the bickering....
bwaslo said:
You're welcome Bill.
It's kind of funny. I've helped out two people having problems with oscillating amplifiers due to high-capacitance cable. Both cases were the identical situation - a woofer amp in a passive biamp setup was oscillating. I guess in that situation, the amp and cable are looking into a big series inductor in the LPF on the woofer side of the passive xover. So at 1 MHz or so where the amp tends to oscillate, the speaker itself looks like an open. The funny thing is, this is the very application where a low-inductance, high-capacitance cable won't help at all!
panomaniac said:
Yes, I also noticed that someone posted that same link a day earlier in the Blowtorch thread. 🙂
panomaniac said:
I suppose we have always known it was like that, so whats there to say
Others have claimed that if all variable influence was removed, all cables would be the same
Could be so, but fact is that reality is different, with many different variables
And the effect i well proven by the measurements you mention
Maybe we dont comment further for exactly the reasons you mentioned 😉
Personally, I dont care much about it
I do my own things, and let others do theirs
Im only intersted in anything useful, that could improve my sound
Things that doesnt matter have no interest
How does that article show that it's something other than differing R, L, and C (that is, the load impedance) causing these differences in amp behavior? Were the cables matched in all these values?
And what happens if the amp connects to the speaker with no cable?
Seems like a test on amps rather than cables.
BTW panomaniac, glad you stopped by to make yourself feel superior to us all here. We'd hate to think your ego was losing its inflation.
And what happens if the amp connects to the speaker with no cable?
Seems like a test on amps rather than cables.
BTW panomaniac, glad you stopped by to make yourself feel superior to us all here. We'd hate to think your ego was losing its inflation.
panomaniac said:
Who ever said cables didn't measure and sound different? It's the BS reasons given on virtually every hi-end cable site. Tara labs included, piles of crap analogies so the layperson won't be "confused".
See....? 😉
What's the title of the thread?
Not "Do cables measure different?"
The point might be that they do make a difference and that can be measured in traditional ways - or in new, innovative ways if the old methods don't show much.
But it's entirely my fault for getting suckered into threads like this. I think that it's going to be a good discussion of what might, or might not make cables sound different. But it's not that at all.
No, it's a Soap Opera for the Audio Boys. You can leave the show, come back 3 years later and the same characters have the same issues. The plot has advanced not one bit. 😀 The goal is NOT to resolve the plot. The goal is purely entertainment.
Nothing wrong with that, as long as you know.
What's the title of the thread?
Not "Do cables measure different?"
The point might be that they do make a difference and that can be measured in traditional ways - or in new, innovative ways if the old methods don't show much.
But it's entirely my fault for getting suckered into threads like this. I think that it's going to be a good discussion of what might, or might not make cables sound different. But it's not that at all.
No, it's a Soap Opera for the Audio Boys. You can leave the show, come back 3 years later and the same characters have the same issues. The plot has advanced not one bit. 😀 The goal is NOT to resolve the plot. The goal is purely entertainment.
Nothing wrong with that, as long as you know.
A little surprise maybe for those who check in only every three years to b***h about something he isn't participating in, but there is almost nothing that measures the same other than things you can count. We can measure a lot of things with very good resolution (sometimes needing expensive test gear). Give me any two cables of nominally identical make and I'll bet I can measure a difference between them. That's not hard nor in question.
I think a lot of what is being said here is right on topic, and no it wasn't all settled by an old summary article in a trade magazine (interesting though it was). Isn't the point whether those known differences are things that someone can hear? Pointing out the differences that exist is on topic, proposing new or describing past listening tests is on topic. Acting like an above-it-all snit ... isn't on topic.
(And now this post is drifting off topic, and we all have better things to do, so... end.).
I think a lot of what is being said here is right on topic, and no it wasn't all settled by an old summary article in a trade magazine (interesting though it was). Isn't the point whether those known differences are things that someone can hear? Pointing out the differences that exist is on topic, proposing new or describing past listening tests is on topic. Acting like an above-it-all snit ... isn't on topic.
(And now this post is drifting off topic, and we all have better things to do, so... end.).
panomaniac said:
Frankly most people here, including myself, are not quaified to comment on the detailed behavior of dielectrics and conductors at the atomic/quantum mechanical level. The discussion tends to decend into inaccurate analogies like electrons are like the water in a stream and impurities are like rocks making eddy currents or references to cable makers white papers that are no better. So we are left with the R, L, and C's that we know and love. As of yet no one has taken up the simple challenge of even trying to show if these are enough.
How much can you discuss, "yes, cables make a difference but it's probably just the equivalent circuit that matters" without even trying to put it to the test?
bwaslo said:
Who? Me or you? Or Seinfeld?
And who said it was settled? You or me - or Kramer?
Who was off topic?
Scott makes a very good point.
O.K. Fremer's name keeps popping up in connection with that test. Scott really needs a good friend to tell him there's no "Fremmer" in the Carver Challenge.
As good as the ear performs at certain frequencies (1kHz to 5kHz - pretty much where the audiophile lives), it's never good enough for some people.
John
scott wurcer said:
In the world of microwave and RF simulation, including EM simulation, this problem has been worked ad nauseum. For example, in the microwave world, people are interested in distributed filters. These can include a topology known as "interdigital filters" where the "digital" in this context refers to "fingers". Such filters use a model where N transmission lines are coupled together, known as "n-coupled lines". The mathematical model of these can actually be derived from EM field equations as necessary, and consists of an RLCG matrix. That is, the RLCG scalar parameter idea generalizes to a matrix where two or more lines are coupled. Once the RLCG matrix is found, there is a formula by which the y matrix can be calculated. That gives the needed form for AC nodal analysis, which can then be used in SPICE AC analysis, or any other simulation software that handles y-parameters.
I've been personally involved in verification of simulated results of coupled lines and other structures starting from simulation of Maxwell's equations on a grid or mesh using an EM simulator, and ending with a y-matrix, at frequencies up to about 40 GHz, against the final physical structure measured on a network analyzer. The theory works. Of course, the R, L, C and G terms must all be functions of frequency for the simulated and measured data to match, as one might expect.
panomaniac said:
Thanks for bringing that up again. In his original post Andre said, "An interesting link that came up on another thread showing what happens if real speakers are used for cable measurements:"
To me the article is about some measurements of a system, not some measurements of cables. And the system is not specified, what amp? what speaker? We do not know if the same results would have been obtained if these were changed.
The right hand plots Figure 6.8 (speaker load) shows the difference to the system that swapping the cable makes, and to me the effect is very small (probably inaudible). The right hand plots Figure 6.7 (resistor load) are also very similar between cables. The fact that there is a huge difference between 6.7 and 6.8 seems to surprise the authors yet the cables were the same in both cases.
There is nothing surprising in the rest of the article about the behavior of cables, just measurements that indicate a lot about about the RF enviroment that the tests were carried out in.
If you want to prove something new about cables, this article doesn't do it for me.
Excluding psychoacoustics for a moment and focussing specifically on speaker cables, there are two questions being confused.
Question 1:
Could there be an audible difference in a given system caused by swapping cables where:
1) there is very little measureable change (1dB or less) in system frequency response (measured at the speakers) between one cable and another, and
2) cables are level matched (measured at the speakers), and
3) there are no significant 'other' influencing factors external to the system that may effect 1 or 2 (ie. RFI, EMI, supply voltage variations, mechanical vibrations etc.), and
4) under controlled test conditions, consistently discernable by listeners.
Question 2:
Could there be an audible difference in a given system caused by swapping cables?
The answer to Question 1, so far, is no. However, Question 1 imposes control conditions that bear little or no resemblance to a 'real world' listening environment.
The answer to Question 2 is yes.
This is because in the 'real world' different cables can:
a) alter system frequency response (1) in different ways
b) provide audible level differences (2) between them (frequency response variations, differences in LCR etc)
c) often be subject to 'other' factors (3) that impact system frequency response.
For example, consider a cable that attenuates midrange frequencies only by 3dB vs. one that attenuates low and high frequencies only by 3dB
The listener would 'hear' (perceive) an apparent difference of 6dB in the midrange!
Cables are an integral part of a system and as such need to be considered in the context of the system.
Cheers,
Alex
Question 1:
Could there be an audible difference in a given system caused by swapping cables where:
1) there is very little measureable change (1dB or less) in system frequency response (measured at the speakers) between one cable and another, and
2) cables are level matched (measured at the speakers), and
3) there are no significant 'other' influencing factors external to the system that may effect 1 or 2 (ie. RFI, EMI, supply voltage variations, mechanical vibrations etc.), and
4) under controlled test conditions, consistently discernable by listeners.
Question 2:
Could there be an audible difference in a given system caused by swapping cables?
The answer to Question 1, so far, is no. However, Question 1 imposes control conditions that bear little or no resemblance to a 'real world' listening environment.
The answer to Question 2 is yes.
This is because in the 'real world' different cables can:
a) alter system frequency response (1) in different ways
b) provide audible level differences (2) between them (frequency response variations, differences in LCR etc)
c) often be subject to 'other' factors (3) that impact system frequency response.
For example, consider a cable that attenuates midrange frequencies only by 3dB vs. one that attenuates low and high frequencies only by 3dB
The listener would 'hear' (perceive) an apparent difference of 6dB in the midrange!
Cables are an integral part of a system and as such need to be considered in the context of the system.
Cheers,
Alex
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