Not really. But I can see a lot of effort being put into testing for an entity that may not even exist on a system.
The check I earlier detailed for troubleshooting imaging defects is one such test. While I designed it to look just for this, it is possible that other system problems would give a false positive or negative. As an engineer I would prefer to start with a hypothesis, find an entity that can be altered at will, then use that for an audibility test.
But I will fully support anybody who wishes to try audibility first with recommendations and controls I think may be necessary.
Jn
I can't find this - possibly due to trying to do it at an airport on a phone... Please can someone link to it?
And PS - You've blown it JN - an engineer using an apple product? 😀
I was is a meeting once with some top management and marketing guys from a very large German company. There were also us engineers.
One of their guys pointed out that you could tell who the engineers were by looking at their phones. All the engineers had android, all the pointy hairs ( The 10 Best Pointy-Haired Boss Moments From ‘Dilbert’ | Bamboo Innovator ) had apples. He said "apple is like being a penguin in a zoo. You have a nice but tiny area to live, someone comes along and feeds you. But you re still in a zoo. Android is like a penguin in the antarctic, you can go where you want, do what you want, you are free. But someone may come along and eat you..."
Oh, and because it's always worth a watch.... YouTube
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I get that a lot.
My first pass effort leading a group to fix some motion control problem resulted in a three order of magnitude improvement with first pass software revision. (The guy who wrote the new code is awesome.)
Which can only mean....
Today I was the windshield.
Tomorrow I may be the bug.
This imaging test effort might be a bug moment, who knows. To me it's the journey, what is learned along the way by all, and who you meet.
Who knows, eventually I may put a stereo in my living room.
Jn
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No, it was analog. Slopes measured acoustically, of course.
I'm on the way to redo-it "digital". Everything to re-discover....
I don’t know that it’s true that more engineers use Android devices. I’ve used all of them, but there are a lot of engineers using iPhones. More electrical than software in my experience. Probably my favorite was a Windows Phone, Nokia Lumia Icon (930).
I have an iPhone XS Max right now as my primary phone, but I also have used Nexus 6P, Pixel XL, and Pixel 2 XL for years. My company develops for all platforms so I make sure I use everything. If Google could stop ruining Pixels with hardware defects then I would consider going back. It’s still a trade off with no clear winner IMO. I dislike closed ecosystems and the awful UI decisions iOS is stuck with, but my inner perfectionist prefers the iPhone hardware.
The only thing I can say is that I will not use Android other than stock Android from Google. No Samsung crap software for me. A shame, because they do better hardware than Google - but no, I don’t want your UI skin, bloatware, and Bixby.
Audio related, I really do like the new rev 2 AirPods. The sound quality is just adequate, but the convenience is unmatched. Microphone functions better than expected on calls, too. They don’t isolate much so they are perfect for office use for me.
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A 5m zip cord, driven from Zg=0 ohm and open at the end, has settling time of the output voltage not about 1us, but close to infinite time, if the driving step signal is fast enough to excitate standing waves in the cable. Please stop talking about my understanding of t-line behavior and concentrate to yours. You suppose you understand how t-line works, that's fine for you.
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You got me there. I was so dying to see how he did the left hand thread with right hand tap...simple..😀
I also love how he converted the cuttings to stool steel (I thought that was a typo).That was some pepper and an even more amazing cat. I do like the humor.
Year or two ago I was having a dickens of a time tapping some aluminum, couldn't for the life of me get it to work. Ruined two pieces trying. Turned out I had a left hand tap.
Sigh.
Jn
Sigh..
I had purchased an IPad, an Imac21, and I6s for my wife, so inherited all. I rarely use the IMac.
At the time, neither of us wanted to play the antivirus upgrade thing, so figured non PC for her was better.
Windoze at work, and for my CNC and EDM builds in the basement. But at home I won't connect to the net, air gap security. At woik, my w95 and w98 machines are also air gap. At first, I detached from the net because the tool tip velocity calculations I needed derived from four of the 9 physical axis was taking me over 80% of the 100 MHz pentium 1 capacity, the occasional look-see at the net would stall the calculations, and the motion card interpolated motion cue would empty, killing the program. When ITD stopped antivirus support for 95 and then 98, there was no looking back.
Jn
That video was great. It was a riot watching both of them struggling to keep straight faces at the dongle discussion.
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True but irrelevant to audio. No steps in audio. At low frequencies a line does not behave like an LC ladder but an RC ladder. No waves. No waves means no reflections.jneutron said:
Where do you buy a 93.6 -j79.2 resistor? You would need to have a calibrating 'resistor' which includes capacitance too. Possible, but did he do this? I suspect not.
That only works if the characteristic impedance of the line is pure resistance. It won't be resistive over most of the audio frequency range.gpapag said:
Actually it is worse than that. At most audio frequencies there are two separate effects:PMA said:
1. the cable is very short
2. the cable does not support wave propagation because R and C dominate
To get wave propagation you need L and C to dominate, which typically starts around the top of the audio band. A short audio cable should not be compared to a very short RF cable, because the very short RF cable does not have effect 2.
Not all frequencies. All frequencies where wave propagation occurs. That means L and C dominant, so not mid and low freq audio.scott wurcer said:
To try to end-up this war about ultra HF cables behavior, I just have a simple question.
That is the only thing that matter for us.
Apart the lumped elements of the cables, that can have an influence, stable amp side as a load and speaker side as a source, on the position and the speed of a speaker at a T. instant ?
I ask this question because, reflections in speaker cables ? Never heard nor measured such a thing. Only impedances (litle, depending on the impedance curve of the speaker) and (little, depending of the amp) capacitive effects.
When i was interested by this kind of "sound of cables" question, my way to figure out was comparing the two sides of a speaker cable connected with realistic devices both sides.
i can ask this question an other way: Are-you fighting to be the first to try to kill a dead horse ?
That is the only thing that matter for us.
Apart the lumped elements of the cables, that can have an influence, stable amp side as a load and speaker side as a source, on the position and the speed of a speaker at a T. instant ?
I ask this question because, reflections in speaker cables ? Never heard nor measured such a thing. Only impedances (litle, depending on the impedance curve of the speaker) and (little, depending of the amp) capacitive effects.
When i was interested by this kind of "sound of cables" question, my way to figure out was comparing the two sides of a speaker cable connected with realistic devices both sides.
i can ask this question an other way: Are-you fighting to be the first to try to kill a dead horse ?
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Just one more remark: "forward" and "reflected" waves are just fictive and they only serve to our imagination what happens in the transmission line. The only physically real values are v(t;x) and i(t;x), values of voltage and current in a defined point of time and geometrically defined point of the line. All else is a fictive model.
You also are guilty of being a carpenter, as in the only tool you have is a hammer, so everything must be a nail.
As I said, in the first 10 to 20 uSec, the TL is applicable, and it matches exactly the LCR distributed response. But hey, is it floats your boat, use the LCR. Bottom line, they will produce the exact same results.
Honestly, your problem is not your EE knowledge as I admire what you know. It is your lack of integration of human hearing capabilities with respect to inter aural timing discrimination. Inverted bandwidth of a 1.2 uSec delay has frightening frequency implications, and it completely overruns our actual hearing capability frequency wise...
But yet, it is an actual measured entity.
Jn
the small secret of Kenwood L-series:
Kenwood Sigma Drive - Manual - Technical Guide - HiFi Engine
and its inventor's page:
LM3886(IC)
CERENATE
By the way, most of its patents are in the ultra low noise SMPS...The photos on its site aren't the amp output , are the SMPS waveforms.
He's just one of those engineers that nobody ever heard of, but as with the U boat...the Japanese will give their secrets away only after the war ends and only if they loose 🙂
You remain wrong on this IMO, for a short line the R is almost irrelevant and the lumped L/C solution matches the t-line solution almost exactly. At least 4 independent people have posted the simulations of this. The energy in a short line is stored equally in the L and C. I just showed the numbers two days ago for 10m of RG58, you are welcome to show me the error.
The telegrapher's equation at low frequencies is applicable for extremely long lines for what happens at far distances from the source. A very short line does not propagate disipativley (R/C). R and G are inconvenient necessities they are not inherent to the problem i.e. if one could build a superconducting vacuum line there would only be L and C (e0 and mu0) which are the basic physics.
Wow, I guess all the TL experts on the planet can go home now, game over..
You are however, correct about v and I.
Which is why I have been trying to get you to understand how the cable alters the I at the speaker terminal based on the LC of the cable working with the R of the load.
Measure I at the speaker terminal with a time resolution of 100 nSec and a span of 20 uSec using a step of roughly 200nSec rise. Then run the range of resistances equivalent the the impedance range of a real speaker, say 6 to 60 ohms.
Jn
Just one minor comment on this.
As a wave is propagating down a line, the energies stored in the L and C are exactly the same. This also applies to free space and within any material.
A short speaker run on the other hand..we load the end at some low number, say 8 ohms, but the line may be 150 ohms RF. So the system is forcing the line to be charged to much greater inductive energy storage than capacitive.
The only way for the cable to arrive at that final (non natural) ratio of inductive to capacitive energy is through the multiple pass reflections. Therin lies the settling time.
Jn
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