Digital sampling and stair-stepping explained

I completely agree this should be a sticky...it's one of the best explanations ever of digital audio and I can't count how many times I've posted links to it.

However, can I respectfully suggest a title change to something like "Why digital signals are NOT stair steps" or something similar?

...just so people don't get the wrong idea!
 
I found this video posted on another forum and thought it would be useful here.

D/A and A/D | Digital Show and Tell (Monty Montgomery @ xiph.org) - YouTube

Nice video! I think I need to see it a couple of times to understand completely whats actually happening.. Also Im strangely confused.. If 8 bit signals only rises the noise floor compared to higher bit signals. Then why the old 8 bit soundcards were not capable of giving any descent sound quality?? I still remember my first 8 bit soundcard. And obviously my old casette tapes sounded much better.. And the man in the video claims the analogue casette is comparable with around 6 bit digital audio.. Wich everyone can know is not the case... Do you remember yourself how the old 8 bit sound cards sounded? Terrible.. no descend sound at al.. So he is showing and explaining something.. but also something wich has to do with hearing is missing.... Guess I really need to see it again....
 
The 8 bit sound cards were also lower sample rate, if I recall correctly. Also, the digital noise floor is both worse sounding and not as transparent as the noise floor of a cassette tape.

I'm pretty sure he was referring to the dynamic range between the noise floor and clipping of a cassette tape is the same as the range between the noise floor and clipping in an 8 bit signal.

Dynamic range is not the only, or the most important part of recording quality.
 
I'm not sure why I saw this thread, but I had not seen the video before, so just had to say it's one of the most intelligent pieces of video I've seen in ages. Of course, it's 9 years old, which may have something to do with it...
 
I'm not sure why I saw this thread, but I had not seen the video before, so just had to say it's one of the most intelligent pieces of video I've seen in ages. Of course, it's 9 years old, which may have something to do with it...
The stair-step model is more of a theoretical model, as the actual model would be points and points of threshold that characterizes a bit level value.
 
Nah, it's not a theoretical model, it's a easy way for people to misrepresent reality as outputting via a sample and hold circuit rather than sample dots or lollipops with interpolation between those samples. Then they can complain that they can hear the stair steps and explain that's why analog is better.
 
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