[Albedo]

When one at last are coming around and to an end, guess what?
 
The reference was to the Norwegian measurement... which showed a clear distortion in the fourth harmonic, but of course.. there are two different views to it's audibility. One side tends to think of themselves as faaaar more credible with their statistical approach and in some  way are saying that others are in facts naive idiots under the clear influence of placebo and nothing else.
 
Cables are at best subtle, but writing others off is a very ineffective strategy.. and the myth continues, a better way is maybe to focus on the shift of perspective and exactly how small a difference there is when viewed from another angle (empathy), that is... not claiming that there's only one truth, the one and only.. way, no wonder many feel they are up to their neck.. and just labels it all as a broken record.
 
No one knows e-v-e-r-y-t-h-i-n-g... in a DAC 4th harmonic produces a non-harmonic spur, which means that the 4th harmonic produces deterministic jitter. An adequate filter is normally not possible as the the frequency of a non-harmonic spur cannot be predicted, it will be seen as two symmetrical non-harmonics with the same level on both sides of the carrier.
 
Some feel to have a parade... well, jitter sidebands are what exactly?
 
Jitter is nearly always non-harmonic and are actually quite irritating because natural sound sources do not produce these non-harmonic distortions, so go ahead.. blow your horn.

 

[frenchbat]

This thread is taking an interesting turn...
 
@Albedo : Funny how you're pointing the finger at the "scepticists", while forgetting to point out the same type of behaviour from the "believers". It's easy enough for them to disqualify any comment with a simple "no but you see, your cables are not allowing you to hear this night and day difference, anyway".
 
End of the day, maybe the problem relies in the way most of the people's asking the question. Looking for the "ultimate proof" is an easy way to flatter the ego, but it's actually anything but scientific. Reverting the order of the discussion could help avoiding the often sterile discussions we see here. I'm ready to accept any valid argument as far as it's also provide a theory backing it up, and the conditions for it's falsifiability. I'm afraid we're lacking both at this time. 

 

[Willakan]

Wait a sec, how is jitter audibility a "preference?" You don't "choose" to perceive jitter - you either do or you don't. When faced with measurements you...oh wait, you're spouting the bog standard "Well if you listen to your equipment you'll realise this is all irrelevant" line. (BTW, demonstrating the fourth harmonic difference in functional cables is audible would be an incredible thing to do, largely thanks to the vast quantities of evidence relating to the audibility of harmonic distortion and how stupidly small the differences are in cables. You don't even NEED blind tests to demonstrate that the chances of it being audible redefine the meaning of miniscule)
 
There goes that rational debate.
 
Oh wait, you're throwing in a few insinuations that nick_charles is talking out of his behind (go ahead..."blow your horn"), after /startsarcasm *totally* devestating his argument with a totally unsubstantiated statement about your personal perceptions of jitter audibility /endsarcasm. Oh wait, you've also thrown in a sarcastic straw man argument to imply that those who place their trust in measurements are unreasonable. If memory serves, you made a post listing all the alleged ways that those who focus on measurements demean and belittle the other side - you're ticking off all your own entries on the list.
 
If you're going to be such an impolite (to say the least) person you had better make sure the accuracy of what you say is prettymuch incontestable. As it happens, the only thing that is incontestable is your tendency towards incoherence.

 

[Prog Rock Man]

A lot of discussion on jitter concentrates on the sending and recieiving of data and ignores the cable, whilst supposedly being about the cable. I want to see evidence of a cable affecting the signal and then evidence that that only affects bass or treble or sound stage.

 

[Albedo]

My last post wasn't addressed to nick_charles, but I'll leave it at that.. about the miniscule differences in cables.. yes I believe it as nearly unimportant, but the devil is in the details..

Many tests are just the RMMA suite, but the perception of hearing also includes the fourth dimension.. time. Many will argue that square waves doesn't occure, but IMO they are somewhat missing the point.. the importance of miniscule.. as in transients.. for some it's the difference between lifeless digital haze and joyful analog bliss of different harmonics that's not filtered out.

Some manufacturers of cables points to skin effect and resonance, maybe it's affecting the driver impedance and the load impedance (+ amplifier's output resistance) in an audible way as some claim happens in a negative voltage feedback, where there's an "electronic" glaze in the midrange.

I'm not interested in the Total Harmonic Distortion as it's an oversimplification, as in... the summation of all harmonic distortion as seen in the Norwegian measurements.

The haze that some can see through, but others can't... 99% is not perfect for some, others view it as miniscule... bla bla bla...
 
Quote: http://www.aes-uk.org/past-meeting-reports/harmonic-phase-the-missing-factor-in-distortion-measurement/

Beyond the second and third harmonics, the fractions of each order of polynomial become strongly interdependent. For any input signal that is not a sinusoid at full amplitude, it is not possible to add a fourth harmonic without also introducing a second harmonic. The same is true for any other harmonic beyond the third. Also, because the distortion kernel is derived from a series of continuous functions, discontinuities such as corners or jumps in the transfer characteristic cannot be modelled. A final complication is that the signal must be interpolated before waveshaping and decimated afterwards. This prevents aliasing distortion from occuring when the upper harmonics pass the Nyquist limit.

The ramifications of these limitations are powerful. For example, we could attempt to correct a system that distorts audio in a known way, by applying pre-distortion to the input. However, this results in problems. If the system introduces a second harmonic, we might generate this harmonic in antiphase in the input so that it cancels the distortion product. However, the second harmonic introduced in the input will itself be distorted by the system, and will generate a fourth harmonic in the output, and very likely a third harmonic as an intermodulation product. We eliminated the second harmonic, but possibly made the problem somewhat worse. If we then anticipate the fourth harmonic, there will then be an eighth harmonic in the output, and so on. Such correction cannot therefore be performed using analogue circuitry. This rule was often advanced in the argument against the use of corrective feedback when the debate raged in the Hi-Fi community a few decades ago. However, a correct transfer characteristic may carefully be derived in the digital domain by generating a true inverse function, which is effective at least until a certain maximum frequency is reached.

Edit: typo.

 

[bigshot]

I don't see any reason why minute distortion four octaves up from the fundamental is going to be in any way audible. I also wonder how jitter is most audible in test tones of 20kHz, a tone that is perceived basically as sound pressure anyway.

Any time I read about jitter I glaze over and start dreaming of how many angels can dance on the head of a pin.

 

[Albedo]

Harmonic distortion is rarely expressed as THD and "transient distortions result in non-harmonic distortion components which not only alter the shape of the signal waveform, but can change the zero crossing point, as these elements may have some real value, when the input signal is at zero. This leads to the second major family of distortion; time base distortion" -> http://tkhifi.homepage.dk/div/The_%20Negative_%20Effects_%20of_%20Feedback.html

Maybe that's why some go completely ballistic when one mention the Gibbs phenomenon (ringing), but what happens when a guitarist use a distortion effect that "clip the outermost regions of the waveform, causing it to increasingly resemble a square wave as more distortion is applied"? -> http://en.wikipedia.org/wiki/Square_wave
 
Which brings me to vinyl and why some prefers such an antique, the energy and timbre of an instrument (to some) are more real, the attack of the drum (to some) are faster, but also more relaxed. Insanely low levels of jitter may also have something to do with what's above 20 kilohertz -> http://www.its.caltech.edu/~boyk/spectra/spectra.htm
 
Some say that there's more life in NOS DACs, tubes and low levels of jitter, maybe because the fundament is perceived as more realistic compared to the instrument in real life... who knows.
 
Edit: typo & angels have a astral body, thereby they all can dance on the head of a pin.

 

[Duncandun]

any digital signal will not be effected by a cable, either it will work or it will not.

 

[Albedo]

That would be true if there's a clock lock between transport and DAC and that the high precision master clock had it's own PSU, but "cables can “smear” digital signals by attenuating the highest frequencies"
 
Quote: http://lampizator.eu/LAMPIZATOR/TRANSPORT/CD_transport_DIY.html

The SP/DIF signal is a 0,5 V pp square wave. It is VERY FAST. it contains 44 kHZ of samples, each sample is a 16 bits, so it is 16 square impulses, and two channels alternating. So we send 2 x 16 = 32 squares per each sample. Plus some other information embedded like end of word, and clock and checksum. So we have roughly 35 squares times 44,1 thousand = 1,543 million pulses per second.

From Furrier's theorem we know that the square wave is an infinite sum of sine waves of odd harmonics, so if 1,5 meg is our first fundamental frequency, we need at least 10 harmonics to be represented properly to make a square. This means that we need to send precisely the sine wave bundle which includes clean 1st, 3rd, 5th, 7th, 9th, 11th, 13th 15th and 17th and 19th harmonics

The 19th harmonics of the 1,5 meg is 30 megahertz. That is bloody fast, as fast as radio waves.

It means that there is a big demand on cable quality. What is cable quality? Simply speaking, in order NOT TO attenuate the fast signal the cable must have very low capacitance and inductance.

 
 

 

[bigshot]

Quote:

Insanely low levels of jitter may also have something to do with what's above 20 kilohertz -> http://www.its.caltech.edu/~boyk/spectra/spectra.htm

It doesn't matter if musical instruments go over 100 kHz if ears only hear up to 20.
 
And if you want time based error, try comparing the relative size of wow and flutter on an LP to the jitter of digital audio. Thankfully, both are inaudible if the equipment is designed properly.
 
This is all just an intellectual exercise. None of this makes your stereo sound any better. Improvements there are measured in human terms.

 

[Albedo]

Well.. the link said otherwise, so maybe instead of an intellectual exercise one can read the link and find the following.. 
 
Quote:

The common view is that energy above 20 kHz does not matter, but AES preprint 3207 by Oohashi et al. claims that reproduced sound above 26 kHz "induces activation of alpha-EEG (electroencephalogram) rhythms that persist in the absence of high frequency stimulation, and can affect perception of sound quality.

 
 

 

[bigshot]

If it's perceived at all, it's perceived as pressure, not music. Because it shows up on a brain scan, it does't mean you need it for your stereo. There's no indication that frequencies above 20kHz do anything to improve or even affect the sound of music. In fact, I've heard of studies that indicated that rolling off all frequencies above 10kHz did little to affect people's opinion of sound quality in listening tests.

I know what 10kHz-20kHz sounds like. The last octave of human hearing is nice to have, but it is insignificant compared to the six or seven octaves below it. Above 20kHz, there is nothing to hear any more. Music flat out doesn't require super sonic frequencies.

It's important to know what the numbers represent In SOUND. Otherwise you can go on adding digits to the right of the decimal point until the cows come home and not improve the sound of your hifi a bit. The important frequencies are the ones you can HEAR.

Super audible frequency extension for home stereos is the bunk.

 

[Rdr. Seraphim]

Well that settle's it! :rolleyes:

Try this simple experiment. Obtain a high resolution recording of a simple, solo violin. Use a device that allows you to cut off (not roll off) fr about 18K, 16K and so on. Let us know what happens.

In the 70's HK provided to its dealers an excellent LP of the impact of fr on reproduction. Heck, it was evident on the Bose 901s, and even more so one some other more critical loudspeakers.

 

[Albedo]

Timbre has much to do with it, so why do some insist on the more natural sound of low jitter sources?
 
"Striking the farthest left key on the piano produces a fundamental frequency of 27.5 hertz, plus harmonics at 55, 110, 220, 440, 880 hertz, etc. Even though the piano only covers about 20% of the frequencies that humans can hear, it can produce more than 70% of the audio information that humans can perceive". http://www.dspguide.com/ch22/2.htm

 

[bigshot]

I use an equalizer on a regular basis. I know what 16kHz sounds like. And I know about harmonics. The instruments with upper frequency harmonics aren't pianos and violins. It's the cymbals and triangles. Reproducing them up to the 20kHz threshold of human hearing helps a little bit, but most of the action takes place well below 14kHz. What we speak of as treble is several octaves down from those upper frequencies.

Frequency extension isn't important. The balance in the middle is.

I've heard people use the meaningless phrase "more natural sound" describing all sorts of different things from Brilliant Pebbles, to SACDs, to expensive wires, to green felt tip markers on the edges of CDs. It doesn't surprise me at all to hear "more natural sound" attributed to inaudible sound.