Thanks for posting results.
As mentioned it looks rather clean and there would not be any discernable listening diifferences in cables based on the results shown unless you have bat ears which BTW I bet there are those who would say they have.
It does not change my opinion that Ratshack cables SUCK!LOL
I do use them in non critical area's and when I need an affordable cable without going a long way to travel.
Thanks SE & Bruno for the time it took putting this together.
Larry
As mentioned it looks rather clean and there would not be any discernable listening diifferences in cables based on the results shown unless you have bat ears which BTW I bet there are those who would say they have.
It does not change my opinion that Ratshack cables SUCK!LOL
I do use them in non critical area's and when I need an affordable cable without going a long way to travel.
Thanks SE & Bruno for the time it took putting this together.
Larry
NEAR_SOTA said:
Again, the purpose of these measurements has absolutely nothing to do with listening differences. That's a whole other issue which simply isn't going to be resolved just by measurements.
The purpose was simply to get at the truth with regard to harmonic distortion and try and duplicate John's results. That's it.
Hehehe. Even if the Radio Shack Golds were the best sounding cable I'd ever heard I'd hate them !@#$% things. Those ViceGrip RCAs are just horrid.
I don't even use the Radio Shack Golds for purely utilitarian purposes anymore. For that I just use the cheapies with the molded plugs.
You're welcome.
I guess Philips deserves some thanks too seeing as I'm assuming the System Two Cascade belongs to them.
se
Hi,
Probably not by those measurements made but I'm hoping to get some measurements from my friend that are as conclusive as he claimed them to be.
Don't know those but, yes, connectors are very important.
That's why you use Redels and I happen to use Lemos, basically the same thing...
Yeah... "Let's make things better", that's their slogan over here...
Whether or not they actually do is another story.
Cheers,
Probably not by those measurements made but I'm hoping to get some measurements from my friend that are as conclusive as he claimed them to be.
Don't know those but, yes, connectors are very important.
That's why you use Redels and I happen to use Lemos, basically the same thing...
Yeah... "Let's make things better", that's their slogan over here...
Whether or not they actually do is another story.
Cheers,
I have deliberately stayed out of this part deux thread so far
and have only skimmed through it briefly and thus may have
got things wrong. However, it seems quite clear from Brunos
plots that there the possibly visible differences between cables
are so small that they can probably discarded as measurement
errors. On the other hand, I seem to understand that John
did measure clear differences in distorsion between the same
cables on his setup. From a purely scientific point of view we
cannot really make any valid conclusion from this. We have
two conflicting results, and no clear evidence which one is
flawed of if both are. I am not familiar with any of the equipment
used and so cannot comment on which one should be most
reliable. Correct me if I am wrong, but it get the impression
that although John uses equpment he is very familiar with he
had to use it in a non-familiar way, which introduces a lot
of uncertainty factors. However, that is still no reason to
make draw a definitive conclusion from the results. That would
take further measurements by others, preferably on copies
of both equipemnts used and also analysis by experts on
measurement technology of the two systems used.
Note that I am not referring to what seems reasonable to
conclude, not what is reasonable to believe.
and have only skimmed through it briefly and thus may have
got things wrong. However, it seems quite clear from Brunos
plots that there the possibly visible differences between cables
are so small that they can probably discarded as measurement
errors. On the other hand, I seem to understand that John
did measure clear differences in distorsion between the same
cables on his setup. From a purely scientific point of view we
cannot really make any valid conclusion from this. We have
two conflicting results, and no clear evidence which one is
flawed of if both are. I am not familiar with any of the equipment
used and so cannot comment on which one should be most
reliable. Correct me if I am wrong, but it get the impression
that although John uses equpment he is very familiar with he
had to use it in a non-familiar way, which introduces a lot
of uncertainty factors. However, that is still no reason to
make draw a definitive conclusion from the results. That would
take further measurements by others, preferably on copies
of both equipemnts used and also analysis by experts on
measurement technology of the two systems used.
Note that I am not referring to what seems reasonable to
conclude, not what is reasonable to believe.
Yes, experiments have to be repeatable and preferrably on
different equipment to rule out systematic errors. So far
neither result has been repeated by others. Of course, one
has to be more careful with repeating null results, since it
is very easy to get one by using equipment withouth the
proper capability to determine a non-null result if there is one.
different equipment to rule out systematic errors. So far
neither result has been repeated by others. Of course, one
has to be more careful with repeating null results, since it
is very easy to get one by using equipment withouth the
proper capability to determine a non-null result if there is one.
fdegrove said:
You said you were hoping to get some measurements from your friend that you said were as conclusive as he said they were. I asked conclusive of what?
Don't know which ones you use, but all of the Lemo and Fischer CAMACs that I've seen used metal for the shells, housings, etc. Most everything except the insulation. Which models use metal only for the contacts?
Again, conclusive of what exactly?
se
SY said:
As far as I remember, System Two can be configured to internally connect gen out to analyzer in, effectively bypassing the external WUT wire (OK, there will probably be SOME piece of wire, internally). If Bruno could do the same level and termination tests with the internal connection, that would give us the residual of the system in each case. John might be induced to do the same.
/Speculation mode ON/
If we find that both systems measure the same without or with a WUT, that would be a strong indicator that the WUT has distortion products below both pieces of equipment.
/Speculation mode OFF/
That would still leave the explanation of the fact that John measures differences between WUTs. One interesting test for John would be to do a series of tests with a single WUT but with different cable runs/orientations, different times of day, with or without the TV etc on. IOW, John would be asked to use all his considerable mental and physical facilities to prove that he measured his environment instead of his cables. This is asking a lot, but is also the stuff true scientists are made of.
/Speculation mode ON/
If John would measure differences under these circumstances, that would be another strong indicator. If he would measure the same in each of these tests, we still have a problem to solve.
John, are you game?
Jan Didden
Thankyou bruno For Going To The Trouble...... (And Se!)
This to me gives the first question - How are these graphs derived ? - by that I mean how are averaging times and peak hold/release times etc filtering the displayed test results ?.
According to the published graphs, there are variations, and some are quite substantial in the order of 1-2 db.
I regard changes like 1 dB as strongly substantial - in a live system changes of LESS THAN HALF a dB on a FOH or stage monitor graphic eq fader can make seriously substantial differences to the overall tonality of a system.
There is one absolute variable that is not being tested for here and that is 'possibly measurable' possible directionality in all these cables.
Q - If each cable was measured twice (or many more trials) in opposing directions, could this seperate out a directional bias factor, or isolate other differences if enough trials are measured ? - IOW could more experimental trials statistically improve resolution (S/N) of this AP test set ?.
IOW, could enough correctly conducted trials statistically separate out very fine differences according to cable type and direction ?.
The graphs show substantial variations - is this an artifact of the measuring equipment and method ......... or not?
Eric.
Ummmm, when I spend 10 minutes scrolling back and forth between the graphs of all the loading and cable differences, I see quite substantial differences between both cable type and source impedence/loading.Steve Eddy said:
This to me gives the first question - How are these graphs derived ? - by that I mean how are averaging times and peak hold/release times etc filtering the displayed test results ?.
According to the published graphs, there are variations, and some are quite substantial in the order of 1-2 db.
I regard changes like 1 dB as strongly substantial - in a live system changes of LESS THAN HALF a dB on a FOH or stage monitor graphic eq fader can make seriously substantial differences to the overall tonality of a system.
There is one absolute variable that is not being tested for here and that is 'possibly measurable' possible directionality in all these cables.
Q - If each cable was measured twice (or many more trials) in opposing directions, could this seperate out a directional bias factor, or isolate other differences if enough trials are measured ? - IOW could more experimental trials statistically improve resolution (S/N) of this AP test set ?.
IOW, could enough correctly conducted trials statistically separate out very fine differences according to cable type and direction ?.
The graphs show substantial variations - is this an artifact of the measuring equipment and method ......... or not?
Eric.
janneman said:
But if I understand you right, we also bypass the connectors
in that case, and they should probably be considered part of
the test equipment since we are interested in the wires, or?
There are always potential sources of errors whatever one
does. Maybe one should do both what you suggested and
do a test with the shortest possible piece of solid cupper wire,
or whatever, between the connectors?
janneman said:
The AP can do that.
But the purpose of these measurements was to try and verify the high levels of high order distortion that John has been measuring in order to determine whether that distortion was being produced by the cables themselves.
We already know that the System Two Cascade is measuring more than 20dB below where John's measuring and there are no signs of distortion at the levels John is measauring distortion.
So I don't see what purpose measuring system residuals would serve.
But again, the purpose of these measurements was to verify the levels of distortion that John was measuring in order to determine whether or not they were being produced by the cables themselves.
I'll leave you to ask him to do that.
se
Re: Thankyou bruno For Going To The Trouble...... (And Se!)
The plots use time domain synchronous averaging. 256 averages in this case. And like any averaging, there will be small variations between runs. If you flip a coin 100 times and note the number of times it comes up heads and how many times it comes up tails, if you flip the same coin another 100 times, you may get a different tally than the first time.
Great. But what you seem to be overlooking here is that any of the changes going on here are going on at greater than 130dB below the fundamental.
It wasn't tested for because that's not what the purpose of the measurements were.
Ben Duncan already did some measurements with regard to directionality. But like some of his other measurements, they weren't very rigorous and the differences in directionality he measured aren't conclusive in terms of establishing that the directionality is due to the cable itself.
Dunno. What they don't show is any high order distortion products at levels John has been measuring which was the sole purpose of these measurements in the first place.
I think I've asked more than enough of Bruno already so if you want anything else done, ask him yourself.
se
mrfeedback said:
The plots use time domain synchronous averaging. 256 averages in this case. And like any averaging, there will be small variations between runs. If you flip a coin 100 times and note the number of times it comes up heads and how many times it comes up tails, if you flip the same coin another 100 times, you may get a different tally than the first time.
Great. But what you seem to be overlooking here is that any of the changes going on here are going on at greater than 130dB below the fundamental.
It wasn't tested for because that's not what the purpose of the measurements were.
Ben Duncan already did some measurements with regard to directionality. But like some of his other measurements, they weren't very rigorous and the differences in directionality he measured aren't conclusive in terms of establishing that the directionality is due to the cable itself.
Dunno. What they don't show is any high order distortion products at levels John has been measuring which was the sole purpose of these measurements in the first place.
I think I've asked more than enough of Bruno already so if you want anything else done, ask him yourself.
se
Why The Differences In the Graphs ?..........
"The plots use time domain synchronous averaging. 256 averages in this case. And like any averaging, there will be small variations between runs. If you flip a coin 100 times and note the number of times it comes up heads and how many times it comes up tails, if you flip the same coin another 100 times, you may get a different tally than the first time."
So in other words these graphs are not correlated by enough trials to derive meaningful data.
"Great. But what you seem to be overlooking here is that any of the changes going on here are going on at greater than 130dB below the fundamental."
I'm saying that changing the level by 0.5 db over a 1/3 octave bandwidth can be clearly audible - that is a very small proportion of the overall signal.
"It wasn't tested for because that's not what the purpose of the measurements were."
I'm saying that I reckon that the cables need to be tested multiple times in both directions to filter out possible variation due to direction.
"Ben Duncan already did some measurements with regard to directionality. But like some of his other measurements, they weren't very rigorous and the differences in directionality he measured aren't conclusive in terms of establishing that the directionality is due to the cable itself."
I heard the effect plain as day on a friends system the other night.
That none of us has measured directional variation conclusively leads me to think that the testing is not precise enough to be conclusive.
"Dunno. What they don't show is any high order distortion products at levels John has been measuring which was the sole purpose of these measurements in the first place."
At this stage I don't think that these results are sufficient to fully prove or disprove JC's measurements.
The graphs given by Bruno are all different, and it seems that some of these differences are due to loading of the AP test set - IOW is the AP test set really fully up to the task?
Modern radio astronomy is reliant on data sifting to pick out signals BELOW the noise floor - this is not being done in this mode of testing presented here, but is required imo.
Fred did say a while back that he has irrefutable evidence for directionality in digital interconnects - any level of directional characteristic would imply a harmonic distortion behaviour in my understanding.
Eric.
"The plots use time domain synchronous averaging. 256 averages in this case. And like any averaging, there will be small variations between runs. If you flip a coin 100 times and note the number of times it comes up heads and how many times it comes up tails, if you flip the same coin another 100 times, you may get a different tally than the first time."
So in other words these graphs are not correlated by enough trials to derive meaningful data.
"Great. But what you seem to be overlooking here is that any of the changes going on here are going on at greater than 130dB below the fundamental."
I'm saying that changing the level by 0.5 db over a 1/3 octave bandwidth can be clearly audible - that is a very small proportion of the overall signal.
"It wasn't tested for because that's not what the purpose of the measurements were."
I'm saying that I reckon that the cables need to be tested multiple times in both directions to filter out possible variation due to direction.
"Ben Duncan already did some measurements with regard to directionality. But like some of his other measurements, they weren't very rigorous and the differences in directionality he measured aren't conclusive in terms of establishing that the directionality is due to the cable itself."
I heard the effect plain as day on a friends system the other night.
That none of us has measured directional variation conclusively leads me to think that the testing is not precise enough to be conclusive.
"Dunno. What they don't show is any high order distortion products at levels John has been measuring which was the sole purpose of these measurements in the first place."
At this stage I don't think that these results are sufficient to fully prove or disprove JC's measurements.
The graphs given by Bruno are all different, and it seems that some of these differences are due to loading of the AP test set - IOW is the AP test set really fully up to the task?
Modern radio astronomy is reliant on data sifting to pick out signals BELOW the noise floor - this is not being done in this mode of testing presented here, but is required imo.
Fred did say a while back that he has irrefutable evidence for directionality in digital interconnects - any level of directional characteristic would imply a harmonic distortion behaviour in my understanding.
Eric.
Steve Eddy said:
The AP can do that.
But the purpose of these measurements was to try and verify the high levels of high order distortion that John has been measuring in order to determine whether that distortion was being produced by the cables themselves.
We already know that the System Two Cascade is measuring more than 20dB below where John's measuring and there are no signs of distortion at the levels John is measauring distortion.
So I don't see what purpose measuring system residuals would serve.
But again, the purpose of these measurements was to verify the levels of distortion that John was measuring in order to determine whether or not they were being produced by the cables themselves.
I'll leave you to ask him to do that.
se
Steve, IIRC the original purpose was to determine whether cable distotion existed (could be measured) at all. The focus then went to the reliability of John measurement tools. Now if with the AP we can look at the residuals we may be able to answer the original question (with some caveats), kill two cables with one stone, so to say.
Jan Didden
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