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Audible difference between analog interconnects


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What Nikhil is saying is essentially correct, and will be backed up by most experienced DIY members of the forum.

 

I agree with his post. I was just kidding. So many people seem to hate audio, as well as hate people who judge audio components by listening to them. Its like a crime to listen to something other than a spec sheet. If everyone's so worried about getting sold snake oil, why not just buy a snake oil detector and be done with it?

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Perish the thought! I hear oil on snails is delicious.

 

 

Well, oil in the form of butter (and garlic) you bet! Snails don't actually have a lot of flavor, they are mostly just a vehicle for delivering aforementioned butter and garlic. Vive la France!

George

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Both of you are partly correct

 

0 db SPL is the threshold of human hearing

 

0 dbFS is the maximum possible digital level

Actually, neither of you is correct. 0 db SPL is one way of expressing a normal auditory threshold but it's not an absolute measurement. The decibel is a ratio, not an absolute number. There are many sound level measurements, each of which can be expressed as an absolute intensity or pressure level, or as a ratio of that absolute intensity or pressure level to a constant or reference. The formula for a decibel is 10 x log (actual intensity or pressure/reference intensity or pressure), and 0 db is a meaningless term without a reference value and the frequency at which it was measured.

 

In pressure units, the "threshold of human hearing" in a normal, healthy adult measured at 1kHz is in the range of about 2x10-5 Newtons / meter2 (which is the actual pressure of the air against the surface of the tympanic membrane). Pure tone threshold audiometry (i.e. testing for the quietest sound the subject can detect) expresses threshold sensitivity as a ratio of the physical sound pressure level when the subject indicates that he or she can hear the tone to the mean threshold pressure determined by testing thousands of "normal" people. So a simple pure tone audiogram expresses threshold sensitivity at octave intervals (measured one at a time) between 250 Hz and 8kHz, and it does so as a ratio between the subject's sensitivity and "normal" sensitivity. Therefore, a "normal" response (i.e. being able to hear the tone when presented at an absolute pressure level of 2x10-5 Newtons / meter2) is expressed as a 0 db response because it is at the reference level. But 0 db is not an absolute measurement, and it may be a proxy for different pressures and intensities depending on the parameter for which it's used. If you cannot hear a tone until it's presented at a higher level than "normal", your sensitivity is expressed as the ratio between the pressure required for most normal people to hear it and the pressure required for you to hear it. So the term "40 db hearing loss" means that the threshold sensitivity of the ear in question requires 40 db greater sound intensity than "normal".

 

The "threshold of normal hearing" (again, a frequency-dependent approximation derived from testing many subjects and not an absolute reference number) can also be expressed in units of intensity, in which case it is about 10-16 watts / cm2

 

There are many "pressure levels" in use in audiometry and in acoustic science, most of which are usually expressed in db for convenience. The main reason SPL meters and other such measuring devices output in decibels is that it's a lot easier and cheaper to use the electrical potential generated in a standardized gain circuit by the acoustic input than it is to physically measure the absolute sound pressure or intensity. So what you're actually seeing on an "SPL" readout is the electrical potential in volts generated by whatever transducer is being used to detect the sound, not an actual pressure or intensity measurement. And it's calibrated against the voltage generated by a signal at the reference level.

 

And dbFS is a ratio of the instantaneous signal level to the maximum your system can cleanly pass. 0dbFS is the maximum digital signal your system can process, not an absolute measurement - and it differs from system to system.

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LOL! Thanks for your concern. I was a cable skeptic once upon a time ...

 

Sorry for the long post earlier but all I was trying to say was that even the volume control can predispose your setup towards certain cables.

 

Yes, as a long time user of passive volume controls, I am well aware of this effect and interactions. It really is still down to LCR. Nothing exotic.

And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. 

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In discussions about thresholds of perception I think we need to distinguish between the low level threshold and a delta to a much louder signal, the thresholds are not necessarily the same.

 

For example back in my photography days we ran into this all the time, there was a certain minimum amount of exposure before the film changed, below that the negative was clear. BUT when dealing with a significantly larger exposure, a difference in exposure that was much less than the low threshold would make a change in density in the film.

 

So I don't think it is appropriate to make a sweeping statement that a distortion product that is lower than the threshold of hearing HAS to be inaudible, it is a small delta on top of a much larger signal. The threshold of a delta may be much different than the low level threshold. Exactly what the delta is probably makes a big difference too.

 

And yes the human ear CAN hear Brownian motion. When my dad was young he had an ear infection that messed up the built in mechanical AGC in the ear, it was essentially running wide open. He had to wear ear muffs to keep from being blasted by people talking downstairs. But when everyone else left the house and it was very quiet, he could hear people talking many blocks away, and even hear Brownian motion (he didn't know what it was at the time).

 

Of course this was a young person's ear, I'm sure it would be very different for an older adult.

 

John S.

 

Well there is some test info on distortion. That is where this jumped off in the low level discussion. Additive harmonic distortion becomes difficult to nearly impossible to hear around or below -60 db from the signal. I find it a stretch to think adding a signal -80 db smaller than that is going to be audible.

 

While the distortion will be part of a larger signal that larger signal will have minor variations due to the addition of thermal noise. When distortion gets hidden at levels of that or lower they will have an effect on a larger signal that is nevertheless so small it can't be perceived as different than the noise.

And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. 

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Personally, it is my opinion that the low level signals are getting lost in the high level bias for sonic imperceptabilies.

Well there is some test info on distortion. That is where this jumped off in the low level discussion. Additive harmonic distortion becomes difficult to nearly impossible to hear around or below -60 db from the signal. I find it a stretch to think adding a signal -80 db smaller than that is going to be audible.

 

While the distortion will be part of a larger signal that larger signal will have minor variations due to the addition of thermal noise. When distortion gets hidden at levels of that or lower they will have an effect on a larger signal that is nevertheless so small it can't be perceived as different than the noise.

Forrest:

Win10 i9 9900KS/GTX1060 HQPlayer4>Win10 NAA

DSD>Pavel's DSC2.6>Bent Audio TAP>

Parasound JC1>"Naked" Quad ESL63/Tannoy PS350B subs<100Hz

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Hi Bluesman - (grin) Now add the explanation of how Decibels are used because they are logarithmic, along the same lines as temperature, and you begin to express the entire subject, no?

 

Nikki is correct as well, as far as he goes, but the subject does indeed go deeper.

 

I will put my foot in it here, and say straight up - even as a catalyst (such as John described) - a signal at -140db (on any scale discussed) will not be audible or have audible effects in music playback.

 

If it were possible at all- it would be through some mechanism similar to what John described, and since noise at that level is effectively random, the moment to moment effect would be nearly impossible for the human ear to integrate and process.

 

This gets off into fantasy land, and is being presented more for shock and argument value than as anything else. I agree that in audio everything makes a difference, but not that everyhing that makes a difference makes an audible difference.

Anyone who considers protocol unimportant has never dealt with a cat DAC.

Robert A. Heinlein

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I will put my foot in it here, and say straight up - even as a catalyst (such as John described) - a signal at -140db (on any scale discussed) will not be audible or have audible effects in music playback.

 

I feel this is buried in other noise levels. The opposite is my experience. A dac with the noise floor at -150 dB sounds cleaner than one with one with a noise floor at -130 dB. This is listening through an amplifier with a noise floor around -110 dB.

Whether it it noise distribution, linearity, or another mechanism. I can hear it.

 

2012 Mac Mini, i5 - 2.5 GHz, 16 GB RAM. SSD,  PM/PV software, Focusrite Clarett 4Pre 4 channel interface. Daysequerra M4.0X Broadcast monitor., My_Ref Evolution rev a , Klipsch La Scala II, Blue Sky Sub 12

Clarett used as ADC for vinyl rips.

Corning Optical Thunderbolt cable used to connect computer to 4Pre. Dac fed by iFi iPower and Noise Trapper isolation transformer. 

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I feel this is buried in other noise levels. The opposite is my experience. A dac with the noise floor at -150 dB sounds cleaner than one with one with a noise floor at -130 dB. This is listening through an amplifier with a noise floor around -110 dB.

Whether it it noise distribution, linearity, or another mechanism. I can hear it.

 

Hey George - I believe you hear what you hear and it is real. But how do you know it isn't due to some other implementation choice, such as the digital or analog filter? I mean, how are you sure that the extremely low level electrical noise is what is making the difference for you?

 

This stuff is dramatically hard to test, because of all the variables of course. Almost need to have a way to inject electrical noise into a DAC in a controllable manner to see if there are detectable differences in the audio.

 

-Paul

Anyone who considers protocol unimportant has never dealt with a cat DAC.

Robert A. Heinlein

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A perfectly reasonable post. As far as I know, although I have no personal experience, Blue Jeans Cables are a most excellent budget brand. The only 'trolling' thing in the post is the use of the phrase 'snake oil'. To me that implies that it is impossible to buy better cables than Blue Jeans, and anyone who thinks otherwise is an idiot. In my personal experience that is wrong. Maybe we should ban 'snail oil' or at least make people aware that it isn't a reasonable way of disagreeing with people who think that it is worth paying for cables that are better than budget, and the sonic differences are easily heard in a suitable high quality system?

 

While the term "snake oil" is definitely predjudicial, To me, the prejudice generated by using it is against a manufacturer or sales entity who is making or selling a product that they know for a fact is either worthless, or actually harmful.

George

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Perish the thought! I hear oil on snails is delicious.
But, not nearly as good as bourguignon sauce with lots of garlic.

 

While the term "snake oil" is definitely predjudicial, To me, the prejudice generated by using it is against a manufacturer or sales entity who is making or selling a product that they know for a fact is either worthless, or actually harmful.
I doubt that is the case very often, even if owing to self-delusion. Having said that, the outrageous claims made by some belie even that, e.g. remember the "Tice clock".

"Relax, it's only hi-fi. There's never been a hi-fi emergency." - Roy Hall

"Not everything that can be counted counts, and not everything that counts can be counted." - William Bruce Cameron

 

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NOMBE SAID: Funny, just place the word "cable" in any thread and it is troll city.

Thank god for Blue Jeans Cable. Great quality, fair price, snake oil free zone.

 

 

 

 

A perfectly reasonable post. As far as I know, although I have no personal experience, Blue Jeans Cables are a most excellent budget brand. The only 'trolling' thing in the post is the use of the phrase 'snake oil'. To me that implies that it is impossible to buy better cables than Blue Jeans, and anyone who thinks otherwise is an idiot. In my personal experience that is wrong. Maybe we should ban 'snail oil' or at least make people aware that it isn't a reasonable way of disagreeing with people who think that it is worth paying for cables that are better than budget, and the sonic differences are easily heard in a suitable high quality system?

 

 

It was not my intention to use the term snake oil in the manner represented by Mr. Dale. (my fault, I should have expanded my comment or self censored)

 

I only wanted to comment that in addition to quality products and fair pricing, Blue Jeans Cable (BJC) does not make any outrageous claims. I do not believe that it is "impossible" to buy better cables. I do not believe that anyone who thinks otherwise is an "idiot".

In any dispute the intensity of feeling is inversely proportional to the value of the issues at stake ~ Sayre's Law

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Funny, just place the word "cable" in any thread and it is troll city.

 

Thank god for Blue Jeans Cable. Great quality, fair price, snake oil free zone.

 

+1 for some sanity in this thread.

"The gullibility of audiophiles is what astonishes me the most, even after all these years. How is it possible, how did it ever happen, that they trust fairy-tale purveyors and mystic gurus more than reliable sources of scientific information?"

Peter Aczel - The Audio Critic

nomqa.webp.aa713f2bb9e304522011cdb2d2ca907d.webp  R.I.P. MQA 2014-2023: Hyped product thanks to uneducated, uncritical advocates & captured press.

 

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While the term "snake oil" is definitely predjudicial, To me, the prejudice generated by using it is against a manufacturer or sales entity who is making or selling a product that they know for a fact is either worthless, or actually harmful.

Like in the Volkswagen situation, there is no easy way for the audiophile community to know what the manufacturer knows.

What label would you use for manufactures that misuse or misrepresent scientific & engineering knowledge?

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Well, there is the rub, there is no standard or proof of malfeasance for that matter. Only opinions which are the lowest form of knowledge

Yes, that's why 'snake oil' should apply to the product and statements about the product made by (or for) the manufacture.

Leaving the why the manufacture did it part out of the description.

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As a 50 year audiophile I am firmly in the objective camp. My believes are that current technical knowledge supplies all that's necessary for both digital and analog cable designs to deliver a signal from point A to B without any audible degradation.

I remain open to the possibility that there may be something going on that we have

yet to identify. But until the subjective claims of cable audibility can be backed up with both strictly controlled non sighted listening tests and technical measurements, those claims will forever remain just an opinion.

Opinions of which there are a million different ones. How will you find out who's right in the untold numbers of opposing claims?

"The gullibility of audiophiles is what astonishes me the most, even after all these years. How is it possible, how did it ever happen, that they trust fairy-tale purveyors and mystic gurus more than reliable sources of scientific information?"

Peter Aczel - The Audio Critic

nomqa.webp.aa713f2bb9e304522011cdb2d2ca907d.webp  R.I.P. MQA 2014-2023: Hyped product thanks to uneducated, uncritical advocates & captured press.

 

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Like in the Volkswagen situation, there is no easy way for the audiophile community to know what the manufacturer knows.

What label would you use for manufactures that misuse or misrepresent scientific & engineering knowledge?

 

In some cases, e.g. Synergistic Research, it's easy to spot the bullshit. The "explanations" they offer are nothing but meaningless technobabble. If they know better, they are deliberately misrepresenting the product. If they genuinely believe their own statements, they are obviously clueless about engineering. Either way, not someone you want to buy from.

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In some cases, e.g. Synergistic Research, it's easy to spot the bullshit. The "explanations" they offer are nothing but meaningless technobabble. If they know better, they are deliberately misrepresenting the product. If they genuinely believe their own statements, they are obviously clueless about engineering. Either way, not someone you want to buy from.

How very true. When it's not about their products, (or connections to their products) they seem to know a lot about engineering.

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