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Originally Posted by tourmaline /img/forum/go_quote.gif
Not really, without an exception people confirm that dacs with 24/192 upsampling have slighlty more detail and sound more analog, e.g. the slight harshness with 44.1 is gone in the extreem highs. And i just told you why, because of the upsampling there IS no anti aliasing in the frequencies that can be heard, even up to 22 kHz, and speed of sound is better. Beacuse it's in the extreem highs, it doesn't mean everybody can hear them as easily. Maybe that's the problem. Technically 24/192 IS superior to 16/44.1! I have yet to encounter a person that is willing to go back from 24/192 to 16/44.1!
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I don't dispute that 24/192 (and even 24/96) is and sounds better than 16/44.1. Nevertheless, upsampling doesn't mean higher resolution nor necessarily better signal accuracy in the time domain. Look at the interpolating algorithms: They follow a sinc function, thus mimick a low-pass filter at about 21 kHz (that's why oversampling or upsampling is also called «digital filter»). The following analog filter now is just needed to smooth the remaining (192-kHz) stair steps to complete the low-pass filter. The resulting filter curve is the same as with non-oversampling DACs with analogue filters, so the end product theoretically isn't any better than that from a non-oversampling filter design. However, in the real world upsampling or oversampling has its merits because it enables a simpler analog filter, which may be responsible for less signal degradation by the electronics components therein. So note: Oversampling or upsampling doesn't add any high frequencies to the signal from the CD, which is originally low-pass filtered before A/D conversion and finally through the redbook format. Oversampling and upsampling just have a pre-filtering function. The ringing due to the filter steepness is still there (which means the filter still corrupts the signal in the time domain), just with a different characteristic (upsampling causes pre-ringing).
The latter aspect may be responsible for a slightly different sonic result. Also the rounding errors from upsampling algorithms may contribute to a warmer characteristic (thanks to increased harmonic distortions). Anyway, I wouldn't speak of a clear sonic advantage of upsampling (asynchronous interpolation) compared to oversampling (synchronous interpolation) or pure analogue filtering.
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Originally Posted by Febs /img/forum/go_quote.gif
...The vast majority don't care. I'll bet that cheap CD players outsell high-end CD players by a ratio of 10,000 to 1.
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Maybe; but certainly not because they sound better or the same, but because they are cheaper, and the vast majority thinks cheap CD players sound perfect, at least for Britney Spears, Jennifer Lopez, Shakira and the like.
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Originally Posted by tourmaline /img/forum/go_quote.gif
If everybody would be as skeptic as you guys we never would have gotten better CD players, amps, speakers, SACD etc.
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As much as I understand a skeptic position, particularly of someone who hasn't experienced sonic differences with CD players, amps or cables, this statement has some merits. I have followed the different CDP generations myself in the form of occasional updates, and the improvement of the CD sound from the first player generation to what's now available is quite remarkable IMO. And this has happened without any proof that the then CD sound could or should be improved at all. I think the developers themselves were aware of the actual weaknesses, despite the marketing claims about how perfect the CD sounds.
It's good and reasonable to be skeptic. But you also should be able to let your ears decide. What else can you do when it comes to evaluate a musical instrument! (Apart from the fact that the sound isn't the only factor there.)
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| And from a technical point of view, as the graphs show, it is! |
Technically the higher resolution is clearly superior, yes. But I agree with
hciman that it has to be verified if the superiority is relevant for the limited bandwidth of the human hearing. As stated in the graph (drawn by me, BTW), the curves show the signal as it's stored on the CD after D/A conversion and before low-pass filtering (in a schematic form). You have to know that low-pass filtering is decisive to get the right impression of what signal shape actually reaches your ears. After regular brickwall filtering the irregular shapes and the amplitude modulation are completely removed in favor of clean continuous sine waves. What you also have to know, though, is that this result is achieved by introducing a massive filter resonance which at the same time more and more smoothes transients in favor of delayed decay, the higher the frequency within the audio band. And that's a fundamental disadvantage of the lower bandwidth of the CD format, which isn't adequately or isn't obviously illustrated by the graphs.
Back to cables.
[Copy-pasted from a closed thread:] Some years ago I've sent my Metaxas Solitaire power amp to the distributor to get it modified. The modification mainly consisted of the removal of two small inductor coils (with at most 0.05 mH) meant to protect against HF oscillation -- considering the (bipolar) amp's extreme bandwidth -- at the speaker outputs. An accompanying, necessary measure was the replacement of a few resistors against some low-inductance types. So the only physical gain the modification provided was actually a bandwidth increase from the high ultrasonic range to the extreme ultrasonic range. The audible range was virtually untouched by the modification. Nevertheless, the sonic result was impressive: smoother, even less fatiguing highs and higher resolution throughout the spectrum. And this with a CD player as source, hence a signal with a sharp cut-off at about 21 kHz.
So my guess is that for some reason the HF response (...of
cables and electronics) still matters, no matter how band-limited the signal. I'm aware that's not a completely satisfying and not a particularly logical conclusion...
An appeal to the skeptics: Please try -- for a moment -- to accept the above scenario with the bandwidth-enhancing amp modification and its beneficial effect. I have no interest to insist in the sonic improvement if it wasn't real. I have paid some money for it, true, but the main purpose for sending the amp to the distributor was to get it repaired (bipolar amps are quite sensitive to handling errors), and so the main amount to be paid was for the repair, not the modification.
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