batsbrew
there's a lot going on beyond what the human ear can hear....
and it's not all about audio,
some of it is about resolution and math.

 
And resolution beyond what humans can hear is irrelevant for audio intended for human listening.


And the bit depth and sample rate used for DSP processing can be higher than the delivery format when appropriate. 

batsbrew
http://www.lavryengineeri..._for_quality_audio.pdf

 
That's an ancient paper, but if I remember correctly I believe Lavry was talking about straight PCM, not massively oversampled one bit (or multibit) sigma delta conversion commonly used for a looong time now.

batsbrew
the math turns into audible payoff,
especially in the 32 bit floating point math,
but truth be told,
the better target would be 60kHz

 
So, assuming you understand the math you're referring to, can you tell us roughly how many calculations might become audible at a given bit depth?

NO.
 
but i don't really care about that.
 
i do believe, that you can't do any harm by having the highest resolution available for recording...
 
playback, though, is another matter.
 

batsbrew
NO.
 
but i don't really care about that.
 
i do believe, that you can't do any harm by having the highest resolution available for recording...
 
playback, though, is another matter.
 

I would say that one can do harm if one convinces others that they need to do or buy (!!!) things that offer no benefit in the real world.
 
And sometimes people (without realizing it) make themselves look silly by claiming to hear stuff that couldn't possibly be audible. I don't think it's fair to either let people embarrass themselves or buy stuff that doesn't really offer any benefit simply because they don't understand how the math involved in digital audio relates to the real world.
 
OTOH there is of course nothing wrong with going overkill if there is little or no downside involved. 24bit recording is a good example of this, as it allows one to leave lots of headroom to avoid clipping without having to worry about quantization errors.

Higher samples rates are useful during non-linear processing. Think limiting, compression, saturation. These all cause distortion which can cause aliasing. For example, the 5th harmonic of 10kHz is 50kHz, which is inaudible. But if this is processed at 48kHz, then the alias frequency will be 50k-48k = 2kHz, which IS audible. In my opinion that's the main benefit of higher sample rates. But now-a-days, those plugins use built-in sample rate conversion to do their non-linear processing at the higher rates needed to prevent aliasing. So the advantage of running your projects at higher rates isn't as great as it used to be. In fact, higher rates are more susceptible to clock jitter effects, so things may sound better at lower rates anyway.

fret_man
Higher samples rates are useful during non-linear processing. Think limiting, compression, saturation. These all cause distortion which can cause aliasing. For example, the 5th harmonic of 10kHz is 50kHz, which is inaudible. But if this is processed at 48kHz, then the alias frequency will be 50k-48k = 2kHz, which IS audible. In my opinion that's the main benefit of higher sample rates. But now-a-days, those plugins use built-in sample rate conversion to do their non-linear processing at the higher rates needed to prevent aliasing.

 
Sure, but the the article being discussed is about delivery/playback formats.
 

In fact, higher rates are more susceptible to clock jitter effects, so things may sound better at lower rates anyway.

No, I think you mean higher frequencies (meaning the audio itself, not the sampling rate) are more susceptible to jitter. But jitter, at least in terms of audio sampling, has basically been irrelevant for quite some time now anyway.

24 bit makes sense because it exceeds the dynamic range which humans can cope with, while 16 bit is less than that. As is the dynamic range of vinyl for that matter and as for cassettes (remember them)....

Sample rate frequency is a different matter. Too low and all kinds of oddities are the result, as demonstrated by early samplers which operated in the 8 to 12KHz range. There's still a cut-off point however, and by and large most people seem happy enough with a playback sampling rate of 44.1-48KHz. Processing audio may benefit from higher rates and greater bit depth but for the final "released to the world" rendering there's little point in going to a higher sampling rate than the CD standard.

I remember listening to a BBC radio programme a few years ago. It had a couple of guys advocating "HD CD audio". The presenter gave them a blind test of CD specification audio and the same at a "HD" resolution. The HD advocates couldn't tell which was which, for which, after an amount of umming and erming they decided to declare that the BBC's nearfields just weren't up to the job, because if they were then the difference would be "obvious".

The BBC does not use low quality monitoring systems, it uses world class broadcast setups, about which it pretty much wrote the book.....

And let's not forget that many people are perfectly happy listening to low quality compressed formats.

tlw
24 bit makes sense because it exceeds the dynamic range which humans can cope with, while 16 bit is less than that. 

No. This is a common myth, but let's say human dynamic ranges from a jet taking off to a pin dropping in a dead quiet room. On playback you only have that much dynamic range if you play back the recording at the jet-taking-off level. It's not a sliding scale, so if you reduce the jet level by more than a tiny amount then the pin dropping is inaudible. 
 
In the real world no one plays things back at that level in a quiet environment, so you only need enough dynamic range to put the noise floor of the medium below the noise floor of the listening environment or threshold of hearing. 16 bit already does this in virtually every non-contrived real world case (with room to spare).