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That DVD-A only has inaudible shortcomings - watermarking distortions, temporal distortions - whereas SACD has inaudible strengths - ultrasonic filtering of audible music, a mysterious relaxing effect, etc.? Isn't anyone on this board imaginative enough to counter this weakness? How about "Research has shown that listening to DVD-A increases your sex drive?"
Follow Ups:
...assholes.
Why are you continuing with this type of name calling?
Sorry, Rod. Just calling it as I have seen it. I will tone it down, however, as I can convey this point of view with more tact.While I'm here, I still don't like the idea of the hi-rez formats being split up. If it had been done at the beginning, it might have have been a good idea (it might not have as discussion of the two formats can be productive). My issue is that the split was done later on for the wrong reason. It was felt that separating folks was the best way to clean things up. That makes no sense. I will say, however, that things have not been as messy as perhaps many of us thought they would be since the split. I attribute that to many folks being challenged to behave. In any event, I still feel the split is wrong. What you, Chris, and any others involved should be striving for is one board for discussion of DVD-Audio and SACD (including universal players!) that is well monitored and that demands high level discussions. Sorry, but you guys took the easy way out by splitting the board.
As far as I am concerned, DVD-Audio is a high-resolution format, so discussions on DVD-Audio most certainly belong on the Hi-Rez Highway . The name "Hi-Rez Highway" in no way conveys a limit of discussion to SACD.
Finally, I will ask that many others have asked. Where should I post questions about universal players? Should I post them in both places? What a pain in the ass! If I post my questions on just one board, I might not get a full analysis of the player, as the DVD-Audio board will likely favor discussion of DVD-Audio playback capability. The same is likely for the Hi-Rez Highway with SACD.
If you look at the hi-rez marketplace, a growing number universal players are being released. For some companies, a universal player is their only foray into the world of hi-rez audio, and rightfully so. How ironic that at a time when universal players are beginning to occupy a significant plot on the hi-rez audio landscape that this site splits discussion of the two formats. Of course, as I said, this split had nothing to do with audio. There is a reason this site is called the Asylum.
I realize your concerns about splitting the boards; however, the thought process was not as you've surmised. Unfortunately, there's no perfect way to do this. Hi-Rez Highway has been around for a long time, changing the name is confusing and affects a lot of software. It's a lot easier to leave the name and redefine the topic. As to how to split it, there was simply no way to do it and please everyone, so we took the option that reflected the majority opinion.Now, why did we decide to split the boards? Sure, the moderation issues were a factor, but not an overwhelming one. We do try to take a hands off approach as much as possible, so just cracking down is not an option that we like. However, those issues were only a part of the story. In the past, we've split off many, many forums. We do that because of three reasons: 1) The board grows too fast and is too active, 2) A large number of posts center on a specific sub-topic and 3) Specialty groups and less activity promote a better sense of community. I believe that we can agree that Hi-Rez was so active that topics simply disappeared to quickly to allow for thoughtful and lengthy discussions. That high level of activity was also affecting the sense of community.
As to where to talk about Universal players, take your pick. While that creates a small dilema, it's not uncommon. We have 3 tube boards, Tubes, SET and Tube DIY. The problem is the same and it hasn't been a problem. People pick the board where they feel most comfortable, know the inmates the best and feel is most appropiate for their purpose. If your primary concern is DVD-A performance, post about Universal players on DVD. If not, post on Hi-Rez or even Digital if redbook is a driving concern. I think we can all deal with a certain amount of crossover. However, from what I see, much of the discussion lies in the area of new releases and from that perspective, the split around technology seems to be working quite well.
While I listen to my SACD collection.
nt
The only REAL shortcomings I've seen with DVD-A up to this point are lack of titles compared with SACD.
no "PCM signature" or any sign of watermarking on DVD-Ano ultrasonic bat mating calls on SACD or anything at 10kHz or above either
even cds sound quite good under the right conditions
people who have a barrow to push usually find mud along the way
going on about the OPTIONAL watermarking.
Temporal distortions are nonsense cooked up by technically impaired audiophiles.
DSD noise is the real crap you can't remove from a recording without altering the original content.In the brittish Hifi Records Review magazine they did the experiment by overlaying a 24/96 recording with dsd noise. A difference between the original recording and the dumbed down dsd version was detectable.
A real dsd recording suffers more because noise shaping affects the sound through in band filtering. Noise is shifted up in the spectrum and some of the musical content is shifted in the process as well.
nt
I take you are saying that there is no such thing as lossless noise-shaping.
that's as designed and still well above the resolution capability of consumer dacs - it's also above the noise floor of typical analog circuitsthat argument is as spurious as the "PCM signature" argument against DVD-A
Maybe you don't read Stereophile.
have you ever measured the SPL of "ambient" noise in a quiet room? the figure is something like 30-40dB! even in my room (and i live in a quiet street) it can rise to 50-60dB with the fridge turned on (from a different room behind closed doors)let's say you are listening to music at rock concert like levels of 110dB. you are getting an overall S/N ratio of effectively 60-70dB at best.
in a worst case scenario (air-con, projector turned on) the S/N ratio may well drop to 30-40dB
this is all old news to mixing engineers which is why you will seldom hear content mixed at below 30-40dB (an exception is pat metheny who says he deliberately introduces content at -40-50dB for headphone listeners)
the S/N ratio on my old amp was only around 80dB. yet i have never heard the noise floor on this amp, even when cranking the volume all the way to 11 :-) (of course, there is noise if my ears are right next to the speakers, but not at normal listening position.)
so i very much doubt (if the player is performing to "spec") that the high frequency noise in sacd is detectable. of course, this is not to say that the noise may not induce artefacts (amplifier circuits oscillating, speaker colouration, phase shifts, whatever) that are detectable. but these are all equipment limitations.
Once the signal is analog you're correct Christine, because you can hear well below the noise floor. However, a 90 dB S/N ratio is not as good as CD - and S/N ratio is critical with digital sources..
sony/phillips deliberately contoured the noise shaping curve of sacd so that it matches or equal cd s/n ratio in the worst possible scenario, which means typically the s/n ratio is better than cd.
SACD players have a lower S/N ratio than CD above 10 kHz or so, or JA is misleading us. How can you possibly misundertand that?
as i recall (which may be incorrect), the cd digital audio format was designed with a goal of 90dB S/N ratio.the fact that many cd players exceed the design goal is due to techniques such as oversampling.
what i stated was that i believe sony/phillips designed dsd to be no worse than the cd spec (ie. 90dB) in the worst case.
in which case, any s/n ratio better than 90dB is "per spec" in my opinion.
i could of course be wrong and will be happy for someone to point this out. but until then, i am not concerned with the results in stereophile since i don't believe they subjectively impact the listening experience (as stereophile themselves point out).
It shows that DSD has a lower noise/resolution above 10kHz or so than a 16 bit pcm signal.Redbook players with 1 bit dac's and noise shaping show the same noisespectrum but with a rising curve in a higher frequency range.
That's because the 1 bit dac's usually oversample at 128 or 256 times.
in the stereophile review of the sony scd-xa777es, jan 2002 edition, page 129-130, figs 3, 4 and 5 clearly show that the noise level is at around -110dB around 10kHz.yes - it rises sharply after that - to round -92dB at 20kHz in fig 4
which proves my point. these are all "within spec" as far as i am concerned, and at these levels the resolution capability of the dacs and analog circuitry are limiting factors.
what i do concur is that sony/philips marketing blurbs about frequency response to 50 kHz are clearly misleading - the signal is pretty junky above 20kHz. but that's fine, i'm not a bat.
Measurements from the same player but a rise in noise of ~6dB at 10kHz when a signal is played.Clear evidence that the noise gets modulated. And so will musical content in the upper frequency range.
A noise shaper can't differentiate the noise from a signal with similar amplitude and frequency.
"Noise is shifted up in the spectrum and some of the musical content is shifted in the process as well."This simply does not happen. This is a product of your active imagination. No musical content gets shifted. Not even the slightest percentage. None.
Noise output of the SCD 1 with a digital 'black' signal.
The same player's noise with a -50dB test signal.Notice the rise of the noiselevel. Where does that energy come from?
Every player yet measured by Stereophile shows areduced S/N ratio well below 10 kHz. Reduced S/N means either reduced signal or more noise. As the noise is ultrasonic....
I don't remember specifics. I would need to look over what testing they are doing to see what they are measuring. Reduced S/N versus 16-bit CD? Hard to believe. Don't forget there are many types of noise. The quantization noise of Sony's DSD is claimed to be well below the quantization noise of 16-bit CD in the audio range, that is up to 20 kHz, and I see no reason to question that. But there are other noise sources.
Just look in the equipment archives. And yes, the S/N ratio is below CD. JA generally comments that there should be no subjective consequences. I have trouble reconciling these measurements with Sony's claims, but perhaps there is a simple explanation.
and it showed the SACD noise level below the CD noise level up to 11 kHz and above it after that. As you say, JA says this is probably not important. This conflicts with the specs on the machine, which say the SACD dynamic range is higher than CD dynamic range up to 20 kHz. I can't explain this discrepancy. But this is above 11 kHz only.
I have trouble following Frank's modulation argument.
it is not at all clear to me what information is being presented here. The difference between the top and bottom chart is the presence of a dithered 1 kHz tone. This has effects I do not understand. At 10 kHz, the "digital black" is about -110 dB for SACD and about -120 dB for CD (CD is better by this measure). With the tone, the 10 kHz numbers are still -110 dB for SACD but up to maybe
-108 dB for CD (now SACD is better at this frequency). I don't know what this means. JA seems to refer to the chart with the tone when he discusses "dynamic range". I will need to figure out what tests they are doing and what they mean.
It's easy to spot the rise in noise if a signal is played back.
Wat will happen if you lower the signal to 'digital zero' The noisefloor will drop and if the signal goes up it rises.I call that modulation. Now it's only noise but what if a 10kHz signal is present next to the 1kHz tone?
It gets also modulated.
Frank,
I think that it is likely that JA stopped printing the digital black test because he was having trouble with different muting schemes and because he discovered that the presence of a signal was affecting the noise. Perhaps we'll know more when he writes about these tests. What is pretty clear to me is that DSD performs much better in the digital black tests than in the 1 kHz tone tests. Is that modulation? What else would it be.
An even more fun test for SACD/DSD would be to run a series of tests,
with say 100, 1K and 10K test signals and look at the effects of the noise as a function of frequency.I can't prove this, but I believe that the degree of noise modulation will increase as a function of frequency.....
I might not be expressing this well, so this is a 2nd explanation.
I suspect that the higher the frequency tested, the worse the noise modulation gets above the tested frequency.
Regards,
On this page you see both graphs for digital black and a test signal at -60dB at the same page. Setting for both measuremens are the same.
At 10kHz the noise floor at 10kHz rises by 10dB.Clear evidence that the noise is modulated by the signal.
The level of noise isn't really important.
What is important that the so called dsd noise is in fact distortion that doesn't belong in the signal.Frank
For the regular CD player, the noise at 10 kHz is about 10 dB higher with signal compared to without signal.Maybe they put the signal generator too close to the player- who knows.
It's got nothing to do with DSD or the noise being modulated by the signal.
from a signalgenerator next to the player.The rise for the cd signal is less severe than the sacd's modulation but it indicates 1 bit dac technology is used.
The signal modulates the noise there's no doubt about it.
see link. I wonder if you could find any CD player of any design that does not.
"This is due to the high-order noise-shaping used in the Crystal delta-sigma DAC to achieve as high a resolution as possible below that frequency. "It's evidence of 1 bit dac technology and noise shaping
it can be found in the latest Stereophile, in the review of the Ayre D1 DVD/CD player. The plot for the spectrum given the dithered 1 kHz signal is substantially identical to that of the Meridian 508.24. It rises to -108 dB at 10 kHz.They say in the write-up that the noise floor in this graph is the same as the noise floor of the dither in the input signal.
That is your answer. This has nothing to do with noise shaping. They are inputting a signal with a rising noise floor, so that is what they are getting at their output.
This is why all the Stereophile graphs of this test output look pretty much the same.
Certainly, the noise shaper is not moving any signal energy. Nothing of the sort happens.
Normal dither will have the effect that the noisefloor rises across the entire bandwith and with a signal a 1.5..3dB rise should occur.With dsd and noiseshaping you see the rise in noise only above a certain frequency.
Yes, the graphs are generated by a dithered 1 kHz signal. Yes, they all look similar. No, they're not all the same and in fact they can differ considerably. It is the differences in the noise floor at various frequencies that JA draws attention to: they are significant. Frank is right about one thing: noise-shaping leads to a much steeper slope.
this has kind of gotten off on a tangent. The behavior Frank noticed led him to conclude that SACD noise shaping also shapes the signal. I pointed out that the same behavior occurs on CD player graphs. He said this was also due to noise shaping.Well I looked at these output charts for about 5 different CD players. They had slightly different wiggles in slightly different places. But they were all basically the same shape. And then I read the text in the latest issue.
It is very obvious that the change in the noise floor between "digital black" and the dithered signal is primarily due to the noise floor in the input signal due to the dither. It has nothing to do with whether the DAC is single bit or not.
OK this applies to CD players. Now we all know that there is a noise floor that increases in SACD and it appears in the Stereophile graphs to increase rapidly above 8 kHz. This is part of the design.
It is still not the case that the noise shaping shapes the signal. Frank's logic, which was not true for CD, is no more true for SACD.
To test sacd performance with a 1kHz dithered testtone as dsd signal is not logical as dsd should be able to cope with an -90dB testtone at 1kHz on it's own. If dither on a -90dB testtone is needed for good testresults with dsd then sacd would be in big trouble.I think the dither is applied to the 16bit pcm test signal.
And of course the noise is in the dsd signal. And my point is that the dsd noisefloor in that signal is modulated by the signal.
The digital black is just a dsd signal with a signal just high enough to keep the muting circuitry from activating. In effect this is the bottom noise floor of dsd (on that partical player).The question is where the test signal is derived from. From a signalgenerator with noise in it's output or is it a math derived 'ideal' testsignal. In the latter case the noise level should be the same as the bottom noise curve.
If it's from a signal generator the rise in noise level should be the same on different machines asuming the same test disc is used.
Frank,
I'm pretty sure it is the same test signal JA uses for the linearity test.
Except that the SACD players clearly show less dynamic range than CD players above 10 kHz or so, and that clearly is a result of noise shaping - as JA has often remarked. The question remains: why does the increase in the noise floor show up an octave below the ultrasonic level?
is too low to realize the promised specs.The rise in noisefloor is just showing that the noise shaper is becoming less effective beyond a certain frequency.
It also shows that distortion rises and that resolution is dropping.
As I said I still don't understand how these tests relate to the stated specs of the SACD players. They seem to be a lot worse than would be expected. But I need to look into what the specs really say-it is hard to believe that Sony would quote specs that are so completely out of line with test results (or that Stereophile would not note this discrepancy). I'll try to figure this out. To tell the truth, I've never paid much attention to their graphs until now.
Firstly, as JA has pointed out, very few Hi Rez players can deliver even 18 bits of resolution across the audible spectrum. Secondly, that SACD's resolution and dynamic range is frequency dependent in a way that Sony would rather not discuss. However, this may have no subjective consequences (again according to JA).
I've been digging around the Stereophile charts and the Sony specs. The spec for the SCD-1 is 105 dB dynamic range in the audio band, presumably up to 20 kHz. So I looked at the review of the SCD-1 and here is the link to the graph, not with a 1 kHz digital signal but with digital silence. This shows the rising noise characteristic, but it also shows that it stays below 105 dB all the way up to 20 kHz. It is just below this at 20 kHz. Seems to me this is the way the noise spectrum is designed to look. This would agree with the spec.OK, why does the 777 graph not look like this? I would think it should. I would think that machine is operating out of spec and should be repaired. I don't think the noise is designed to be as high as that shown in the graph.
My assumption would be that the 1 kHz dithered tone is a tougher test, and more indicative of actual resolution.
it's nice to see someone taking the time to establish facts rather than conjecture
input, and have nothing to do with the components being tested. JA is paid by the square foot, so he just keeps printing the same graph.
it's not that funny anymore, and not very becoming either
This is also why Meridian changed over to Analog Devices Multi-bit Delta Sigma Architecture DACs in the 5xx and 8xx series.Regards,
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