No I cannot. Nor will I bother. While I am getting old, some things are never forgotten.
Sure, no prob. All systems have a step response time. This is the fastest that the system can move, ever.
A recap, sorry as you already know this..
When a 50 ohm load is placed on a 50 ohm cable and a 50 volt step applied, the load will be at final current the instant the step reaches the load. If a 1 ohm load is used, the first time the step hits the load, there will be a huge reflection, and the load will not have 50 amperes through it, not even close. The next time the wave hits (after reflecting at the source), a little more current will get into the load. This staircase increase in the load current tracks exactly a good LCR model.
This delay is dependent on the mismatch. If the mismatch is sufficient, it will exceed levels which can no longer be considered inaudible. Doesn't mean they are actually audible, but that the blanket assertion that they are not cannot be applied.
As speaker loads vary with frequency, the impedance at any one frequency can be used to determine the equivalent delay at that frequency using t-line. By choosing the cable impedance in the 25 to 40 or 50 ohm range, even speakers that drop to 1 ohm will have delays below any possible audibility.
T-line theory only guides us at to where the cable Z's should be to minimize a differential effect caused by the range of mismatch defined by the speaker. Beyond that, T-line is not as effective as LCR.
To try to use t-line in a simulation with typical music waveforms however, is far too difficult to provide meaningful results. Specific frequency delays within a complex waveform will need an accurate non linear speaker model, and I believe that is currently intractable.
jn
In all fairness, DF has opinions I value, and I wisely do not simply diss any opinion he has without very careful consideration.
jn
I think I prefer the word 'stubborn'.jneutron said:
You can't have it both ways. The models are either equivalent or not. If equivalent you cannot get findings from one and not the other. Your argument has always been that the T-line model provides information relevant to audio which cannot be obtained from a single-cell lumped model. You can't say "They give the same result, yet the T-line is better (although much more complicated, unnecessarily so)". I can say "They give the same result, but the lumped model is better as it is simpler".
Show me where I said "inapplicable" (i.e. it doesn't work) when I meant to say 'inappropriate' (i.e. there is a simpler method giving exactly the same result). If so, I will apologise for creating confusion back then. Then consider that my point has always been that the T-line theory, when used properly, adds nothing to a short audio cable. It may be that for part of the time I was concerned that you were not using it properly (e.g. by ignoring line attenuation - which will reduce the effect of reflections).
You are several days too late. SY already introduced the idea of using QM to calculate the trajectory of a thrown ball. That is a good analogy for what is happening here.marce said:
OK. You don't intend to back up your accusation with evidence. My offer of an apology still stands - if it should be proved necessary by evidence.jneutron said:
So we agree. The simple lumped model is sufficient.jneutron said:
T-line not needed. A single cell LCR low pass filter has an optimum load resistance for achieving a suitably smooth response. It is by considering this that the T-line equations emerge. For example, T-line characteristic impedance is found by considering a single cell and asking what termination impedance will result in the same impedance being seen at the input.
Thank you. For similar reasons I continue to read your posts, although I must admit that at times the Ignore button has seemed like an easy way out!
Ah but I was thinking Quantum😉 (audio) not real world Quantum.....
No info forthcoming so far on directivity, my long quest so far (several years) has not provided me with any meaningful information regarding this phenomena....
I shall go sulk under a brown sky amongst the purple trees said the sad Marce...
Hmmm, brown sky thinking... possibly appropriate.
No info forthcoming so far on directivity, my long quest so far (several years) has not provided me with any meaningful information regarding this phenomena....
I shall go sulk under a brown sky amongst the purple trees said the sad Marce...
Hmmm, brown sky thinking... possibly appropriate.
And I respond to blanket statements. (But the word "Quantum" does apply in extreme case, however not here.)
But this thread reminds me of the not quite logic of:
If a speaker cable is changed from a light gauge to a heavier one there is a measurable difference. That is from the lower resistance of the source now feeding the loudspeaker that has a load impedance that varies with frequency. So there is less variation after the change.
Now if you use cable lifters that does not change the cable resistance.
So the result that cable lifters must have no effect is concluded by some.
There are lots of other issues that also do not change, the question is what does change using cable lifters and if this can result in a measurable change.
Now there are some changes that are hard to measure, but some are simple.
I will still stick to my OPINION that the change in capacitance to ground can cause changes with some system components. I will not dismiss the effect as reported because of issues that most likely would have no significant effect.
Besides JN is expounding on interesting issues yet to be measured by the peanut gallery.
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Again though when you research the majority of feedback regarding cable lifters (not only this site) it is the usual, the difference was a clear as night and day, wifey in the kitchen, it was not a subtle change, my dog heard it 5 miles away etc. Yet any effect is going to be heavily influenced by the surrounding materials, how far the fields extend and how much of this is going to have a serious influence, cable type, current drive etc. etc. this is the problem with most of these type of changes to many variables to regard them as serious experiments. Now I know for a fact that a cables proximity to certain things can have an effect, when doing EMC testing the cables proximity to the big plane on the test equipment can have a very noticeable effect.
So yes in some cases it may have an effect but in most modern dwelling I thing this will be infinitesimally small, if any; not the global panacea that is claimed....
So yes in some cases it may have an effect but in most modern dwelling I thing this will be infinitesimally small, if any; not the global panacea that is claimed....
In the case where nothing was noted, does anyone bother to post this?
And in the case where the amplifier is unstable and oscillating, I would expect a big change. Is there any disagreement on this?
As to what a wife tells a husband, let us not go there...
why does using Quantum to describe a baseball's flight keep coming up - someone rubbing in the fact that gravity is missing from the Standard Model?
isn't it cool enough that General Relativity is needed
isn't it cool enough that General Relativity is needed
How can anyone design or analyze an audio cable when we still know so little about Dark Matter and Dark Energy?
Don't you know that those are some of the well known manufacturers of audio cables?
Ben,
Improved shielding to prevent neutrino interactions within cables, presently smearing the flock out of your stereo image, might prove to be a more attainable step forward.
Dark Matters and Energies come next 🙂
Improved shielding to prevent neutrino interactions within cables, presently smearing the flock out of your stereo image, might prove to be a more attainable step forward.
Dark Matters and Energies come next 🙂
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Gosh no I didn't😱
Without typing reams and reams most seem to have got the point I was trying to make, maybe I didn't word it as succinctly as I should, replacing reputable with audiophool would have been better...
But you keep nit picking you cant make my mood any worse today others have already done that.......
You said "such information on audio cables" and "real sensible data from audio cable manufacturers". Did you mean something else?
Yes I do think you know what I was alluding too, the esoteric beliefs and views put out by the non-professional audio cable suppliers similar to the ones I mentioned... I am aware of data from reputable companies regarding cables but I was specifically targeting my comments to the esoteric side of consumer audio...
Do you understand now.....
The following are what you've said.
# 849: "some real sensible data from audio cable manufacturers, the opposite of say audioquest or synergestic research bunf....."
# 874: "Read what I said, I was referring specifically to audio cable manufacturers similar to the examples I gave, don't twist things or give me silly replies...."
I gave you the answer to # 849.
Tomato, tomahto.
no, do not recreate history. I have been saying the same thing since 2011 (we go a long way back with this). I have stated all along that the t-line model provides an easier view of the latency delays for horribly mismatched cables.
Yah, I'm going to review all our back and forth for the last 4 years...right..
However, since I have been stating that the 2(3) are equivalent, and that the t-line provides different insight, it is good that there is agreement that t-line does indeed provide information consistent with my statements all along.
Within the 5 to 10 uSec I have always been clearly discussing, ignoring line attenuation is of no concern. Also, line attenuation will slow the response even more.
Don't bother offering. The history is too long, we have an awful lot of posts on this.
I have not stated it isn't. I've stated that the T-line provides a different insight.
You are welcome, I state what I feel.
The ignore button has never been a consideration of mine, despite how condescending you have been (IMO). I have however, found others challenge you as condescending where I believed them in error, so used IMO as a modifier to the previous sentence.
jn
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Gawd, it was originally a rhetorical question... I don't know what point you are trying to get across😡
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