All kidding aside in my tongue -in-cheek comment to Scott, if all these tweaks really worked, then many of these companies would still be in business over 20+ years as everyone beat a path to their doors because of consistent results. I get the impression from a few responses, the constant suggestion that some of us are taking the wrong approach to all this or just have small brains.
I just can't see myself slathering the edges of my CDs with green ink again. Never. Nor raise cable off the floor nor worry again that the lettering on each cable is oriented in the same manner. I've heard enough live music in this town (Austin) for almost all of my life (approaching 50 years) to know better than that when listening to my system and tweaking it for 20+ years. Is it close to live music...no...do I know when a tweak gets closer to the illusion that makes my brain feel more like it's the real thing? Yes.
And I highly enjoy the technical posts because it shows me how much I don't know and just how much I want to understand it to make the best choices in practicing diyAudio. And for that, I thank those who are putting in their best effort here contributing their technical know-how.
I just can't see myself slathering the edges of my CDs with green ink again. Never. Nor raise cable off the floor nor worry again that the lettering on each cable is oriented in the same manner. I've heard enough live music in this town (Austin) for almost all of my life (approaching 50 years) to know better than that when listening to my system and tweaking it for 20+ years. Is it close to live music...no...do I know when a tweak gets closer to the illusion that makes my brain feel more like it's the real thing? Yes.
And I highly enjoy the technical posts because it shows me how much I don't know and just how much I want to understand it to make the best choices in practicing diyAudio. And for that, I thank those who are putting in their best effort here contributing their technical know-how.
Really? Even terman knew better, back in 1947.
Perhaps you need to rethink that one.
You've clearly misinterpreted what i wrote.
Actually, you modelled and proved it..
read davis.
jn
You need to take account of mutual inductance. Rosa did it in 1908 IIRC. Anyways, it's now classic and standard for 2 parallel wires.
Yes, I agree the amp bandwidth seems a pragmatic 'thought bandwidth' for such things. Perhaps an octave above even. Doesn't change anything as to TL applicability or lack of, but means one ought to think about load impedance for a decade above the audioband in terms of stability with the amp I think.
Do not expect all cables to be non directional.
I do not properly know the reason/s but ime cables/wires can have an audibly directional characteristic.
Perhaps ingot cooling imparts a direction, perhaps wire drawing imparts a direction, perhaps insulation application imparts a directional characteristic....dunno for sure.
Suffice to say I have been caught out in the past where I had an imaging problem skewing to one side and bal control did not fix the problem...I was tempted to tear my hair out after having tried every elimination test that I could think of.
It turns out that I had fitted halves of the one length of cheap shielded cable to my turntable in opposing directions.
Reversing the direction of one channel cable corrected the image skewing problem.
I have since then repeated this experiment with wire, interconnects and speaker cable and confirmed/repeated this condition.
Curious but true ime....I was also told by a now departed nuclear physicist to expect this directional characteristic !.
Dan.
I do not properly know the reason/s but ime cables/wires can have an audibly directional characteristic.
Perhaps ingot cooling imparts a direction, perhaps wire drawing imparts a direction, perhaps insulation application imparts a directional characteristic....dunno for sure.
Suffice to say I have been caught out in the past where I had an imaging problem skewing to one side and bal control did not fix the problem...I was tempted to tear my hair out after having tried every elimination test that I could think of.
It turns out that I had fitted halves of the one length of cheap shielded cable to my turntable in opposing directions.
Reversing the direction of one channel cable corrected the image skewing problem.
I have since then repeated this experiment with wire, interconnects and speaker cable and confirmed/repeated this condition.
Curious but true ime....I was also told by a now departed nuclear physicist to expect this directional characteristic !.
Dan.
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One would hope that with a competent design there would be no high frequency component present in the speaker wire, this is what EMC and signal integrity engineering is all about...
I would be more concerned with mains borne high frequency noise if you used power line communication for your Ethernet or anyone near by did.
If HF noise is present you want to attenuate it as much as possible, though by the time its got to your power amp output I would say its a bit late, some ferrites on the cables would help🙂
Wont get into detail on directivity, its been discussed to death in many threads and Audio forums, never really discussed on other electronics based forums and literature though...
Its up there with cable lifters and BQPs....
I know I cant convert you to the truth Max, so will refrain from playing any Aussie based music for a week as punishment...😀
Woops Gongs main man is an Aussie.
Its up there with cable lifters and BQPs....
I know I cant convert you to the truth Max, so will refrain from playing any Aussie based music for a week as punishment...😀
Woops Gongs main man is an Aussie.
You mean how much you don't need to know and how little you need to understand to make the best best choices in audio cables. The knowledge needed on audio cables to allow the users to make the right choice has been established and published. It's all over the internet. What you've seen last few pages has been nothing more than one poster trying to show that his * is bigger.And I highly enjoy the technical posts because it shows me how much I don't know and just how much I want to understand it to make the best choices in practicing diyAudio. And for that, I thank those who are putting in their best effort here contributing their technical know-how.
* Use your imagination. 😉
Evenharmonics--do you have any intent to provide content beyond trolling this thread? I find your posts comically ironic, as, at least in my perception, you're the only one involved in a * measuring contest. It's kind of embarrassing to watch and, honestly, you're showing far more ignorance and dismissiveness than anyone else here.
You can certainly disagree with the significance (audibility) of the effect that JNeutron highlights, as several have done (and he himself questions the overall significance thereof), but the physics of what he asserts is very real.
Perhaps I misread his gist, but it comes to me more as, "whether or not it's audible, this is a real effect, and it's easy to mitigate, so might as well."
This thread has been a lot of dragging people, kicking and screaming, into the transmission line (or even lumped element) model in a case where we generally use a much simpler model that glosses over ostensible minutiae.
Differences of opinion? Absolutely. Arrogance beyond friendly jabs among colleagues? I haven't seen them until your attempt to "thought police" things. Consider this a (polite) gauntlet thrown down to provide something meaningful. 🙂
"Very real" for sharp impulses or long cables. Not for audio, where a simple LCR model tells us all we need to know for a short cable.Derfnofred said:
Maybe some people misunderstand what a physicist means by 'approximation'? It doesn't necessarily mean 'rough answer'; it could mean 'extremely accurate answer, good enough for all practical purposes when used appropriately'. As SY said, we don't use quantum mechanics to find the flight of a thrown ball; instead we use the approximation of Newtonian mechanics.
I don't disagree, but isn't JNeutron still pointing out *where* there's a difference in the models? It's very small, as we'd expect (the simpler model is very good for most intents and purposes), but still there--that's what I meant by "very real".
And therein lies the subjective part to ask, "is it significant?" At best, the answer is maybe, and if so, barely.
And therein lies the subjective part to ask, "is it significant?" At best, the answer is maybe, and if so, barely.
Read Terman, either 1947 or 1955.
I have verified his equation to within 4% for the inductance of 2 parallel wires, for frequencies from 20 hz to 100 Khz, from 24 awg to 10 awg. Terman is dead on the money, using pvc or teflon..
And, no parallel wire pairs make it down to 100 nH per foot.
None.
So, please discontinue with made up wires. If you choose to again push nordost valhalla wires, say it up front.
Your last wire set requires foamed coaxial dielectric. You cannot simply make up numbers and expect them to go unchallenged.
jn
Gee, that sounds like davis on page 455.
Of course, not like davis on page 454..
Mutually exclusive information, all on the same paper..
jn
But what JN points is not only vanishingly small, it's based on TL assumptions which don't apply. The better model here actually uses lumped parameters - in this case the TL model is actually the worse approximation.
Here's a mechanical analogy which might help explain why.
Say a thin light horizontal string 1m long is attached at one end to a wall, and its other end is held by some apparatus so that the string is in some tension, but the apparatus can drive a vertical displacement of that end of the string.
If the apparatus drives a fast step change in the vertical position of the end of the string, a displacement wave will propagate down the string and refections will bounce back and forth many times before the string settles in position. This can only properly be described by wave mechanics because rigid body mechanics can only approximate - TL if you like.
If the apparatus drives a very slow smooth change in the vertical position of the string, the string moves smoothly as a single body, there are no reflections and the motion is best described by rigid body mechanics, and wave mechanics can only approximate - lumped model if you like. This represents the case of an audioband risetime signal on a speaker cable, where signal moves super slowly in the scheme of things.
The shorter the string is, the more biased toward the latter case. At very short length of string and very slow motion, the string just moves as a single body, there is no wave propagation, it's meaningless to try to apply wave mechanics to it - that's the scenario here.
HTH!
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If you have read and understood my posts on this thread, you would be saying something else. I have done a double blind test of cable lifters and there's nothing to be gained sonically. It's a total snake oil. Now, do you want to spend time talking about inaudible effects of some audio tweak? Go head and waste your time when it can be better spent on learning why some listeners think they heard a difference from such product.
Read Rosa, 2L - 2M and see what happens as the conductors become close... You've missed mutual inductance. You have to consider it, and measure it, as a return circuit.
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He wouldn't know because he hasn't done an objective comparison of such product. Such question (in bold) would come up from those that are uninitiated. Those would be the same type that cable lifter vendors and other bogus tweak vendors (audiophile fuse, contact enhancer, cable burner...etc.) would love because their minds are easily swayed and their money is easily parted. Those vendors only have to cast doubts in the minds such type of people and the rest is basically automatic. You don't want to be one of those types and jneutron sure isn't guiding you away from such doubts.
OK, here's what Terman has to say on the topic :
Transmission of Audio-frequency power over Moderate Distances
Transmission lines are frequently used for transmitting audio-frequency energy for short distances, such as from one part of a building to another. Such lines differ from radio-frequency lines and ordinary telephone lines in that the length, at even the highest audio frequencies, is only a small fraction of a quarter wavelength. The possibility of resonance, accordingly, need not be considered, and there is no advantage in making terminating impedance equal to the characteristic impedance. The impedance as viewed from the sending end is essentially equal to the terminating load impedance.
My emphasis.
Terman disagrees with you then, JN, and says near exactly what I have posted...........have you actually read this ?
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Dan, if people have decided, for whatever reasons, that something can't have an audible impact then it's highly unlikely they will do open minded experiments - I wouldn't get fussed about it, it's their loss ... 😉.
The trap is trying to come up with a reasonable explanation for what's going on - one can end up looking a bit stupid if it dissolves into a heavy duty technical argument, and one's premise is heavily undermined. For me, the point is to achieve competent sound, and really, I couldn't give one tiny snippet of a bugger as to the "why" in the first instance - the aim is to get complete, experimental control over the behaviour, and while on that journey, or later, the "whys" may start to emerge.
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