JRiver MC Version 18
- Thread starter Ki Choi
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Bruce B
WBF Founding Member, Pro Audio Production Member
noise and jitter would be fine. Then move on to the other "standard" parameters from which other software is measured. if there is an audible difference, you should certainly be able to measure it.
Let me remind you of the ESS video (posted here somewhere) showing noise modulation artifacts in sigma Delta DACs. These artifacts were not shown in the normal set of accepted measurements run on DACs.
Let me also remind you of Jim Lesurfs IQtest which I posted here showing differences in the output between Halide Bridge USB-SPDIF converter & the DACMagics own USB interface. These differences are not revealed by the standard set of measurements.
As far as jitter is concerned, my buddy Pat Digiacomo has the best gear available to do the proper jitter measurements. I think he would be willing to do it. The only problem is that the machine's minimum frequency is 500khz and the digital output would need to drive a 50ohm load. He uses this machine to measure low jitter clocks which oscillate at much higher frequencies. I don't have any device that could meet these minimum requirements. But I think Pat would be willing to measure if someone could make such a device work with jriver and jplay.
My sense of what they say they do is to reduce system activity by prefetching content and such. If the effect of that is lower jitter, then it should be trivial to measure it. I recently did extensive testing of Jitter over HDMI and some over S/PDIF. In my PC I attempted to create a ton of activity and it made absolutely no difference in the measurements. The reason is not the obvious one. When measuring Jitter with high resolution from a PC source, it constantly changes in every snapshot. Whatever improvements or determinants there are, are easily dwarfed by these variations. Hence the reason I could not detect the difference. It is like trying to hear someone whisper during a rock concert! So yes, there are clearly many cases where what they are doing is absolutely in the noise. Question is, if there are cases where this is not, and we can measure noise and jitter so easily, why haven't they or someone else done that? I will accept the best case scenario as a starting point.
I tested three different USB interfaces and could easily measure differences between them with respect to jitter/noise. Since the same DAC is used with/without JPlay, and Jplay is not in control of any hardware metrics/design of the DAC, we don't need to start worrying about the factors you mention. Let's start with the easy answer and rule out that it makes no improvement in jitter and noise as measured all the time.
You oversimplify again, Amir, in your conjecture - Jplay does more than simply prefetch an audio file into RAM. I can't tell you all the details as I'm not privy to them & they are hardly likely to give away their IP but there are a number of playback engines, a number of user controlled settings (not just buffer size) & also a streaming function between 2 PCs
Do you have the results for your USB interface measurements? Did you ever measure a single USB device that showed different levels of jitter because of different operating conditions? I'd be interested in this result too & it would also prove something about the feasibility & limitations of such a test to reveal jitter & noise.
Based on your above comment " When measuring Jitter with high resolution from a PC source, it constantly changes in every snapshot. Whatever improvements or determinants there are, are easily dwarfed by these variations." - you seem to be asking for measurements that you yourself couldn't do?
No, it is the other way around. The nature of a rock concert is such that it masks someone whispering. It is not a problem with my ears not hearing whispers in general. By the same token, a PC is complex device that is performing numerous tasks, some on specific timing, some not. It is like a thousand people speaking and shouting at once. My testing showed that changing the activity level on the system did not rise up above this level of this background activity. That is, you can whisper or even shout in any manner you want, you still won't rise up above the level of rock concert.
To use a different analogy, if I have 100 microvolts of noise and you vary it by +-5 micrvolts, it is not material. That such a variation gets lost in the noise damns he improvement and not the instrument and certainly not the person performing it
. Remember, the instrument is far more sensitive than our ears are in this case.If you are accepting that what they do doesn't reduce the readily measured noise and jitter on a PC, then we have a starting point for a discussion. Do you?
I have an interesting and esoteric question. I saw on another board where someone offered up the theory that WAV and AIFF are superior to FLAC and ALAC because of the "electrical noise" created in the processor when unpacking the lossless file.
Is this bunk or does it have merit. For the record, try as might, and I HAVE tried..I can hear no difference between FLAC and WAV/AIFF on my ethernet network.
If I had an interest in showing that different file formats sounded different even though they contained the same information, I would look for any plausible reason, flattering those who thought they had Golden Ears, while running no risk whatever of it being proved either way. Electrical noise fits the bill perfectly. I could state it without any proof or foundation, and the job would be done.
No, it is the other way around. The nature of a rock concert is such that it masks someone whispering. It is not a problem with my ears not hearing whispers in general. By the same token, a PC is complex device that is performing numerous tasks, some on specific timing, some not. It is like a thousand people speaking and shouting at once. My testing showed that changing the activity level on the system did not rise up above this level of this background activity. That is, you can whisper or even shout in any manner you want, you still won't rise up above the level of rock concert.
To use a different analogy, if I have 100 microvolts of noise and you vary it by +-5 micrvolts, it is not material. That such a variation gets lost in the noise damns he improvement and not the instrument and certainly not the person performing it
If you are accepting that what they do doesn't reduce the readily measured noise and jitter on a PC, then we have a starting point for a discussion. Do you?
What I said was that you were asking for proof of a difference between a system running JRiver Vs a system running JRiver + Jplay or any scenario involving Jplay with measurable differences. You are saying that your measurements weren't able to uncover any such measurable difference when you tested a USB device & then changed the PC systems operating conditions. You cited so much background noise from the PC's activity possibly masking any difference between the configurations.
Now you are asking for this measurement difference to be shown for JPlay but yet you can't produce any such measurement yourself. Therefore you accuse Jplay of not producing data & distrust it's doing anything, as a result??
Again, I find your position untenable. You really are saying that if it can't be measured then it can't be heard - pretty much the standard argument in all these things. But yet you have already admitted that the differences might be buried within the noise you measure from the PC. If I understand you correctly you want to suggest that because the general noise from the PC isn't reduced by Jplay that therefore it isn't having any effect. You discount the possibility that there still can be noise differences between the two configurations, correlated noise ,for instance, at a level that is below this background noise. Noise modulation as Opus11 has talked about before.
So my answer is no I don't agree that if Jplay doesn't reduce this overall noise then it is not making any audible change.
I already told you of the DACMagic Vs Hailde Bridge & the IQtest. If you go to stereophile & look at the jitter results for both of these devices can you see an obvious difference? Yet there is a universally accepted agreement that they sound different. If I couldn't point you to the IQTest, you could equally make the claim that there is no difference between the two devices because there is no measurable difference shown - in the standard tests.
Let me point you to a guy who attempted to measure "Load-induced Jitter" in PC audio http://archimago.blogspot.ie/2013/03/measurements-hunt-for-load-induced.html
His findings - there's no such increase in jitter with increase in processor load!!
But for one little aside - "Conclusion: The motherboard's internal DAC is relatively jittery compared to the USB DAC's tested below. But symmetrical jitter sidebands are no different whether CPU or GPU load high. Bottom line... I can't even seem to stimulate more jitter with the motherboard's own internal DAC by increasing CPU or GPU load. One consistent finding though is that bit of noise between 8-9kHz - usually whenever I strain the GPU.
Amir, Is this the elusive little bit of noise rearing it's head above the noise floor that you were alluding to?
So does extra PC load cause extra noise - in this case we see an example of it.
His findings - there's no such increase in jitter with increase in processor load!!
But for one little aside - "Conclusion: The motherboard's internal DAC is relatively jittery compared to the USB DAC's tested below. But symmetrical jitter sidebands are no different whether CPU or GPU load high. Bottom line... I can't even seem to stimulate more jitter with the motherboard's own internal DAC by increasing CPU or GPU load. One consistent finding though is that bit of noise between 8-9kHz - usually whenever I strain the GPU.
Amir, Is this the elusive little bit of noise rearing it's head above the noise floor that you were alluding to?
So does extra PC load cause extra noise - in this case we see an example of it.
You are repeating the words but not letting them sink in
. Once more: instead of sitting on my behind and hypothesizing, I did something about it: I attempted to measure the analog output of the DAC while I changed system load. That test showed that system activity does not rise above natural fluctuations in system performance. This was a real measurement and invalidated the theory that there would be a difference. If I measure something and it is not there, that is what it proves. It does not prove that the measurement is no good as you keep saying. The reason the change did not register is not the fault of the instrument or the operator. If you drop a ball in the ocean, you won't change the waves reaching the shores.Jplay implies that by reducing system activity good things come out of it. I have tested that theory and it has failed in practice. You want me to go against my own data and full knowledge of the entire system from hardware to software and pipeline and trust wishful thinking. I am not going there. I like them to prove it in some manner. Unlike buying a turntable, R2R, thick cables, fancy looking gear, there is no other redeeming value to this software if it does not improve performance.
I have more than argument. I have some data, and total knowledge of the system, perhaps far more than they do. I also showed initiative in running and testing things which neither you or them seem to have. If there is nothing measurable, let's have them and you confirm that first. That by itself would be useful thing. As it is folks are left to believe that there are measurable differences in noise/jitter. If we told everyone that it made no impact in either, I am sure views would change and not likely for the better.
If you have no data, you no data. You don't get to extrapolate from that to something like "Opus said there is noise modulation." You simply have no objective data that there is an improvement. And that is that.
Heck forget about that for a second. Please explain to me why this software can't make the sound worse. How do you know this software has not changed the spectrum of noise/jitter to be deterministic or more in-band (in audio frequency)? Without measurements you don't know, right?
So what if I wrote a plug-in for Jriver that simply took the date in and passed it back out. In other words, it did nothing. But I claim that it improves the sound, makes digital audio less digital, adds air, etc. because I am "polishing" the bits to make them clearer. Are you saying that as a consumer, you would not want any tools to smoke out my deception here?
Let me ask more broadly. Is there any audiophile product that would give you pause as far as its ability to improve the sound?
I talked to him this afternoon. He is interested in the topic of computer induced jitter/noise. After we talked about different ways to measure, he doesn't think it's even possible for anyone to do the measurements and get any meaningful data. I give up. You guys have at it. This is one of those never ending debates that is impossible to prove or disprove. All I know is that, if there is a difference, it's so small that it doesn't matter in the context of all of the other things to worry about; eg. room/speaker interaction etc.
Let's cut to the chase here - you are so caught up in measurements that you forget to listen - to trust your ears!! If you did (blind) you would realise that Jplay sounds superior to JRiver. I start with that piece of data (as I would with any audio device), which trumps all your measurements - something you have not done. Everything else is just a side issue. I'm just surmising what tests might reveal this improvement but I'm not really that bothered as I can hear the difference which is all that counts. I was hoping for an interesting discussion but see that it's fruitless - once you have listened, maybe it can progress in a separate thread - identifying the measurements that might reveal the differences but until then I'm outta here.
Yes there are many audiophile products that I'm very suspicious of as I can't see how they could possibly work & I understand your viewpoint. Usually these products have esoteric names, Quantum blah, blah or Shakti blah & esoteric prices to boot & I don't see them offering free trials so I've never tried them.
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OK that's a good definition of noise. So where exactly in the chain do you think the application (JPlay) comes in? If not at the end before the DAC, what can it do about noise induced below it in the chain of events? Related to that, do you think it's coded to filter out RFI?
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