Some information/comparisons/clarification wrt vinyl and Redbook CD

[Jakob1863]

I don't think I've ever knowingly heard the hiss inherent to the 16 bit digital system... I guess it's there if I turn the volume right up, but usually buried in the ambient/mic noise of most recordings. When I used to use reel-to-reel, however, I was acutely aware of its noise - to the extent of building my own companding noise reduction for it.

A figure of 50-55dB dynamic range would, on the face of it, be about the same as cassette with Dolby B. CD isn't remotely the same.

No, that´s a misinterpretation, as the systems usuable dynamic range figure is something different than SNR.
It denotes what is possible signal wise if considering the whole chain beginning at the microphone.

 

[Cosmik]

No, that´s a misinterpretation, as the systems usuable dynamic range figure is something different than SNR.
It denotes what is possible signal wise if considering the whole chain beginning at the microphone.

Are you saying that CD is inadequate for the purpose, or more than adequate? Did you see this thread that says that 120dB is needed for a truly transparent recording medium?
https://audiosciencereview.com/forum/index.php?threads/philips-red-book.2138/#post-57869

And 16 bit isn't too far off:

Thus, 16 bit audio can go considerably deeper than 96dB. With use of shaped dither, which moves quantization noise energy into frequencies where it's harder to hear, the effective dynamic range of 16 bit audio reaches 120dB in practice

(maybe at only 44.1 kHz, the achievable range is a bit less, though)

 

[Jakob1863]

Are you saying that CD is inadequate for the purpose, or more than adequate? Did you see this thread that says that 120dB is needed for a truly transparent recording medium?
https://audiosciencereview.com/forum/index.php?threads/philips-red-book.2138/#post-57869

And 16 bit isn't too far off:

(maybe at only 44.1 kHz, the achievable range is a bit less, though)

As usal (unfortunately) the answer will be "it depends" .
The 120 dB requirement isn´t a new one, afair it can be traced back (at least for prefessional use) to around 1985 - 1988 .

Although (again afair) the sound levels in the audience for orchestral sounds were measured around 105 dB, it was at the conductors desk more like 114 dB.
For other material the maximal sound levels were even higher in some cases, reaching up to ~130 dB .

I´ll try to retrieve some more informations/numbers and write in more detail in the next days.

Edit: the "dB" numbers for sound levels are "dB SPL" (sound pressure level)

 

[fas42]

Have done experiments encoding just using 8 bits, with optimal dithering - and this works. Just a pleasant hissing sound in the background, and subjectively I don't feel anything is lost in the presentation. The "dynamics" of the music, as something with gusto and drive, is still all there - and at the other end, pure 24bits can fail dismally at getting this right. Again, it's not a simple numbers game ...

 

[Blumlein 88]

Okay looking more carefully at how much signal range you can get onto a recording. Let us say you'll record 120 dbSPL. Okay one of my quieter microphones has self noise of 4 db. So you have 116 db left right there. One of my better microphone preamps would add 2.5 db to that in its operations. So we are down to 114.5 db overall range of the signal. I'm leaving out the nasty details, but could supply them if needed. Now to get the levels to add up best possible I'll actually need a bit of gain to get that 120 db SPL peak to be at though not over 0 dbFS. I'll end up with about 109 db overall once that happens.

All of that is something that can be captured by well dithered 16 bit if one is careful and does no superfluous processing. Recording in 24 bit gives a little headroom and makes it possible to have the final result stuffed into dithered 16 bit. Now one might thru close miking and making stars line up perfectly do a little better than that. This microphone in the example is quieter than most in self noise, but it also can record sounds louder than 120 db SPL at low distortion. The ultimate limit is going to be the microphone pre at 128.5 db range if one were to somehow manage it, and in this case the other factors will still limit that to 114 db.

Now this ignores ambient noise at the recording location. It ignores the ambient noise at playback. Chances are you loose at least 20 dbSPL there, and even if sticking to frequency bands where our hearing is most sensitive you'll still have 10 db SPL ambient noise. So the potential to exceed the dithered dynamic range of CD is right on the edge. Maybe so, maybe not, and in most cases simply not possible. Few, few, few recordings will manage it.

So dithered 16 bit a limit on possible recording quality due to reduced dynamic range? Theoretically barely possible by a few db at the most optimistic. In the world of available recordings it probably is not the case anywhere close to 1 recording out of 1000.

 

[Wombat]

We need a digital descriptor equivalent to ANALog.

 

[Thomas savage]

We need a digital descriptor equivalent to ANALog.

I’m more of a CHOCILog fan myself ..,