SACD vs. Blu-Ray for audio quality/sonics


I would like to hear any comments on the Audio quality/sonic merits of SACD vs. Blu-Ray.  Thanks
whatjd
There is indeed quite a bit of research that suggests that anything more than cd red book is  unnecessary, but also some weak indications that a bit more might just make a tiny difference, but only just. Since the resolutions of Bluray and SACD are both well above this, there is no chance in the world that you can hear any difference between these two higher resolution formats.
There are two caveats, however. The first is that for recording purposes in the studio, working in higher resolution makes life a lot easier. But that logic does not apply to the distribution format.
The second is that for comparison you really need the exact same mastering/recording. SACD or Bluray is often mastered differently from red book discs, with a wider dynamic range etc. So you are not necessarily comparing like with like. And of course you need material that was recorded in high resolution in the first place. Using an analogue tape as a source is meaningless. If you want to do a meaningful comparison you need to use the same high resolution file, and downsample it to 16/44 for comparison. When this is done, differences have tended to disappear.
In practical terms, the choice between SACD and BD is simply a matter of practical convenience and availability. Fortunately a great player like the Oppo 205 will play all of these formats, so you do not even have to choose. Just have your cake and eat it. Enjoy the music.
@willemj

You seem mathematically adept or inclined.

Non random Jitter is a big audible problem even in amounts that nobody thought could be audible.

In a sense, jitter is a form of timing or clock non-linearity.

There is another pernicious form of non-linearity in all but 1 bit sigma delta DACs. The small non linearity between individual levels on a ladder DAC creates similar problems to jitter.

The solution is upsampling or much higher sample rates.

Despite having little or no musical content above 20KHz - higher sample rates and upsampling will help randomize DAC non-linearities.

This is a major reason why upsampling sounds so much better in most DACs and why high sample rate files sound better. Nothing to do with our hearing high frequencies and everything to do with less sharp filtering and randomization of inherent DAC non-linearity.

willemj - I agree with #1

re #2 - IIRC, they selected only studies for meta-analysis where the redbook layer of an SACD was used.

In general, it seems wise for a consumer to choose SACDs as the mastering/recording will usually be done well and not "mastered for itunes) or some such.

Finally, I thought the major effect of using high sample rates was that you could avoid brickwall filters