Understanding Sample Rate

[mansr]

5 minutes ago, crenca said:

This is the most concise summary of these realities I have ever read.  Really for the first time, I now understand why delta sigma DAC's are the norm in the market right now...thanks!!

I was talking about ADCs, but the same concepts apply in reverse too.

[mansr]

28 minutes ago, Summit said:

“The sampling theorem assumes infinite sample precision”  Yes and that’s the problem with theorem.

There is no problem with the sampling theorem. Quantisation is a separate problem with its own theorems.

[mansr]

8 minutes ago, beerandmusic said:

The more bits and/or the higher the sampling rate, the higher the resolution. That translates to a 20-bit 96kHz recording having roughly 33 times the resolution of a 16-bit 44.1kHz recording. No small difference.

That's a nonsensical comparison.

[mansr]

Just now, pkane2001 said:

Please tell me it wasn't the Nyquist-Shannon sampling theorem page!

And this is the reason you should always verify anything you read on Wikipedia with independent sources.

[mansr]

Just now, beerandmusic said:

I have no issues the the nyquist theorem...i have issue with it's misappropriation.

Good thing there isn't any to speak of then.

[mansr]

13 minutes ago, semente said:

Could you point me to the believers' dictionary?

No, but do try The Devil's Dictionary.

[mansr]

6 minutes ago, Cornan said:

@beerandmusic I am really impressed with your defensive and yet objective approach. Keep that spirit going and you will do good things over here! ? Keeping @mansr  at a distance is worth a gold medal of honour in my book!

What have I ever done to you? Seriously?

[mansr]

3 minutes ago, Cornan said:

Well, I do like you but you question just about anything I'll post.

I hardly ever respond to your posts, so I wonder what gave you that idea. In fact, I completely ignore most of the threads where you are active.

[mansr]

54 minutes ago, Ralf11 said:

wrong as usual sandy - go for a walk

 

or something

Maybe I should post a picture of a puppy.

[mansr]

13 minutes ago, sandyk said:

Among other things, Don claims to be able to design DACs that are impervious to the problems that afflict most DACs with USB inputs etc.

Doesn't seem all that difficult.

[mansr]

3 minutes ago, sandyk said:

Yet another thinly veiled personal attack.

I'll grant you, your personal attacks are rarely veiled at all.

[mansr]

2 hours ago, Confused said:

How big is your shed?  In other news, I have just had the need to use some toilet paper, and with my curiosity peaked by your post, I checked for the country of manufacture, and all it says is "Manufactured for Waitrose", which while quite posh, leaves me none the wiser.  It's pretty good paper though, I'm very happy with it.

Sainsbury's toilet paper says it's manufactured in the UK.

[mansr]

7 minutes ago, crenca said:

Oh dear.  Is she playing the roll of Ted Denney or does she innocently believe such is the case?

I think she actually believes it. Remember she still uses analogue mixers and tape, digitising only the final master. As far as I know, she has no education in science or engineering, so she's probably simply extrapolating her experience with analogue formats to digital. The quality of analogue tape really does matter, and in her mind, presumably, CDs are just another format subject to the same rules. The truth is that her expertise at recording music (and she seems to be quite good at that) simply doesn't mean much when it comes to the technical side of things.

 

Ted Denney, on the other hand, I can't see being anything but a charlatan. There is no way he doesn't know the technobabble he spouts is gibberish.

[mansr]

15 minutes ago, buonassi said:

Sorry to be a noob here. Who is this person in the recording industry that is referred to as 'she' and 'her' in the last few pages of this topic? I did try and read back as well as use search tools to find the answer myself but wasn't successful. 

 

I'd like to seek out her work and have a listen myself. 

Cookie Marenco of Blue Coast Records. The recordings are excellent.

[mansr]

53 minutes ago, jabbr said:

I think it’s certainly possible that physical CD-R might sound different directly played.

I won't say it's impossible, but it should be a rare exception. If the player has trouble tracking or maintaining focus, or if the error rate is abnormally high, it could maybe, possibly cause some noise on a poorly designed player. Any two spec-compliant discs played on decent gear should sound the same.

 

53 minutes ago, jabbr said:

Barry Diament says the same.

He says a lot of things.

[mansr]

4 minutes ago, Ralf11 said:

Is it possible for a large number of such errors to cause a difference in SQ due to interpolations not being correct?

I was referring to correctable errors.

[mansr]

50 minutes ago, jabbr said:

Dont want to beat a dead horse too much but it was Gordon Rankin from whom I first heard the SQ advantage of ripping a CD to hard drive and subsequent playback. He has a rather good technical background. 

I have no respect whatsoever for Gordon Rankin. He is a liar and a jerk. He'll say whatever will sell his latest snake oil.

 

50 minutes ago, jabbr said:

In in any case there are many people who have heard SQ differences between CD and hard drive, so CD to CD doesn’t seem too far a leap.

Comparing a CD to a rip involves completely different hardware. A slight difference isn't entirely implausible. Two good discs played on the same player really shouldn't sound different. If they do, I'd call the player defective.

[mansr]

10 minutes ago, jabbr said:

Oooohhh... You may have whatever opinion you have, and whether you have respect for him is your own decision, but this post is over the top and personal. There is no need to make personal attacks and does nothing to help your own position. Not that you care, apparently.

Go look at his tone towards me and others in the MQA on Dragonfly thread, then tell me he isn't a jerk. People have been banned for less. In the same thread, he also made various factually incorrect statements about his own design. If that doesn't make him a liar, I don't know what does.

[mansr]

2 minutes ago, jabbr said:

Making "factually incorrect" statements does not make someone a liar,

No, not necessarily. If the person genuinely believes the statements to be true, he is not a liar. Someone who knowingly makes false statements is a liar. Since Gordon was talking about his own product, the only way for him to not be a liar is to be incompetent, which is just as good a reason to distrust him.

[mansr]

2 minutes ago, beerandmusic said:

Actually i said i DIDN"t agree that higher sampling rates "round" things.

I said, and still believe that it provides more detail and "airyness"....not round anything.

Whatever you think it does, it doesn't.

[mansr]

5 hours ago, Don Hills said:

Well, let's take the worst case and add an order of magnitude to be sure. Say 500 nano seconds.

 

1/(2pi * quantization levels * sample rate).

1/(2 pi * 8 * 44100) = 450 nano seconds if I've done the sum correctly.

That's 3 bits.

So even 3 bit encoding is more than enough as far as timing is concerned. You'd have trouble hearing a 3 bit (of 16) encoded signal at all, let alone discern a timing difference. And if you boosted it to normal listening levels it'd be too noisy to be called "hi fi". 

 

Can we agree that time resolution, even at 16/44.1, is a non issue?

I must correct you guys on one important thing regarding this calculation. The time accuracy depends on the frequency of the signal, not the sample rate. Instead of 44100 Hz in your formula, you must use the frequency of the signal. At 22050 Hz, 16-bit sampling gives an accuracy of 110 ps. At 1 kHz, it is about 2.5 ns. Another way of looking at it is that the sample precision determines the minimum detectable phase shift regardless of frequency. At higher frequencies, the same phase shift corresponds to a shorter time.

[mansr]

Just now, psjug said:

And for better time accuracy, 24 bit can give this without changing the sample rate.

Of course. Sample rate isn't even part of the calculation for time accuracy. Only signal parameters and sample precision matter. That said, the sample rate obviously needs to be high enough to capture the signal in the first place.

[mansr]

1 minute ago, esldude said:

I remember working thru this coming to the same conclusions.  People who should know better than me insisted the other formula was correct based upon sample rate.

They were wrong or answering a different question (what is the minimum time shift detectable an any frequency).

 

1 minute ago, esldude said:

In any case time resolution was below 10 microseconds people worry about. So I dropped it.

At 20 Hz we get a precision of 120 ns. Really nothing to worry about. Those minimum phase filters people seem to like do a lot more damage.

[mansr]

13 minutes ago, esldude said:

Robert Stuart uses the same formula.  Working the geometry of sine waves I had the same idea as mansr. And that amplitude would matter.

 

Seems obvious that a 10 khz sine that barely changes the next sample by 1 LSB would have too small a difference in the same time period at 5khz.

Correct, and amplitude matters too. In the formula, the figure for the number of levels should be in relation to the signal peak, which might be smaller than the maximum possible.

[mansr]

Previous discussion:

 

There is a slight mistake in the derivation as I used 1 LSB rather than ½ LSB as the threshold. Sorry about that.