High resolution audio. The science, or lack of...?

[fr0g]

You are totally right of course fr0g. But this has been done to death and I fear that you're banging your head against a brick wall trying to explain to someone who doesn't understand Nyquist-Shannon theory why CD quality 16/44 is already past the limit of what humans can can hear and anything higher than that doesn't make any difference to the sound.

:wall:

I find this post quite depressing Steve. Coming from one of the most positive, friendly people in internet land.

Information is key. Information is education.

Not only that, but I am genuinely interested in what certain people have to say on the subject in the form of actual proof that Nyquist-Shannon is "not all that".

I think people who hold on to seemingly obvious false impressions should also be taken less seriously when presenting so-called reviews, whether it be a magazine, or an individual.

Terms like "The higher resolution files really popped..." should, imo indicate that the review is over and the reviewer is simply writing any old rubbish to appease an audience...and should ultimately be ignored as any basis for advice...

unless of course, someone, somewhere can provide an actual link to a paper that tells us otherwise...??

 

[steve_1979]

I find this post quite depressing Steve. Coming from one of the most positive, friendly people in internet land.

You're quite right there again fr0g (irritatingly so in fact ).

Blame my negativity on a stressful day at work today. :type: :wall:

Thanks for the compliment though.

Information is key. Information is education.

+1

When people understand, science and logic can pervail. I've noticed a gradual but definite change on various hifi forums over the past couple of years regarding the number of people seeing sense where things like cables and high rez audio are concerned. Even the benefits of active speakers are accepted by most people on forums nowadays.

 

[fr0g]

I find this post quite depressing Steve. Coming from one of the most positive, friendly people in internet land.

You're quite right there again fr0g (irritatingly so in fact ).

Blame my negativity on a stressful day at work today. :type: :wall:

Thanks for the compliment though.

Information is key. Information is education.

+1

When people understand, science and logic can pervail. I've noticed a gradual but definite change on various hifi forums over the past couple of years regarding the number of people seeing sense where things like cables and high rez audio are concerned. Even the benefits of active speakers are accepted by most people on forums nowadays.

Indeed.

What I don't get...Is the reticense of people to link after proclaiming that Nyquist is old news and long since disproved by science. I would seriously LOVE for someone to give me a reason to go out and improve the quality of my music.

Unfortunately, I (for the moment) think it's all bluster coming from people who don't want to know they have been conned.

 

[lindsayt]

It's a big fat marketing half truth to state that the 16 bit CD format has a dynamic range of 96ds, because it doesn't have a usable dynamic range of 96dbs.

Distortion in the CD format increases as the recording level decreases. By the time you get to 50, 60, 70 dbs below maximum recording level you start getting increasingly noticeable distortion, especially at higher frequencies.

Try it. Make a recording of a professionally played solo grand piano where the recording level ranges between -95dbs and -65dbs below maximum possible, using the CD format, and at the same time, make a recording onto 2 track 1/4" tape running at 15ips at -30 to -0dbs and then compare them using class A amplification and good speakers to see which sounds more like a real piano.

If CD format really did have a usable dynamic range of 96dbs it would sound at least as realistic as the tape recording.

Perhaps you care to explain why you think this may be the case. And no, I don't have the equipment nor the grand piano nor the professional to play it at hand to do the actual experiment as you suggest.

Here's a decent reference by the way for those who genuinely want to understand the engineering background to all this.

The big problem I have with the source you're quoted comes in the first paragraph of chapter 3:

"The definition of proper sampling is quite simple. Suppose you sample a continuous signal in some manner. If you can exactly reconstruct the analog signal from the samples, you must have done the sampling properly"

A piano does not produce a continuos signal. It produces signals with transients, decay, that are not at a single steady frequency, but which has a fundamental frequency with harmonics overlaid on that frequency. It's a complex signal. Not the simple one discussed by your reference.

Also, think about it the decibel range for a moment. In terms of wattage power it's logarithmic. 16 bit gives you 65,536 different possible values for representing the power at any particular sample moment. If you spread that out over 96dbs you're bound to get a coarsening of the sample at one end of the power range.

The decibel scale is mind boggling.

If 0 db's = 1 watt

-10 dbs = 1/10th watt

-20 dbs = 1/100th watt

-30 dbs = 1/1000th watt

-40 dbs = 1 ten thousandth of a watt

-50 dbs = 1 one hundred thousandth of a watt

-60 dbs = one milionth of a watt

-70 dbs = one ten millionth of a watt

-80 dbs = one hundredth millionth of a watt

-90 dbs - one billionth of a watt

-96 dbs = quarter of a billionth of a watt

Now can anyone explain to me how our 16 bit sample, giving us 65,536 different possible values can capture our logarithmic power scale ranging from one quarter of a billionth to one without a lot of coarsening at one end of the scale?

A 32 bit sample would be better as this can represent 4.29 billion different values.

 

[chebby]

The BBC were getting 78dB from 13 bit / 32K when they started rolling out digital (PCM) distribution of FM to their transmitters in the early 1970s.

They found that 78dB (up to frequencies of 15kHz) was far better than any existing source (hi-fi tuner or turntable or tape) could manage at that time.

 

[lindsayt]

Lets put this 13 bit 32k sample rate to the test then. Make a recording at -75dbs to -45dbs at this sample rate and compare it to a 15ips tape recording of the same performance at -30dbs to -0dbs to see if 13 bit really does have usable dynamic range of 78dbs.

13 bits gives us 8192 different possible values.

 

[altruistic.lemon]

So the experts from the AVI forum don't want to try a simple test! Amazing, really, since it might prove what you think you know. Talk about closed minds.

Go on, give it a go, won't hurt and might even prove you right.

Seriously Lemon, give it a rest.You are starting to look a bit silly. The "test" is useless and will prove nothing no matter what the result is. What frequency does your equipment play back ?

I know, you take a test to see how many litres of coffee you can fit in a spoon...It would be equally usefull.

And if you knew me, you would seriously not call me "an expert from the Avi forum"...to be honest I find that place one of the most close minded, authoritarian places to post. Agree with the consensus and you're "in", otherwise you are a trouble maker. It is a VERY useful place, but not what I would call "home", or in the slightest bit "fun".

But that is to be expected from a manufacturers forum. At least they don'¨t tolerate subjective nonsense about cables,isolation platforms, PSUs and other completely meaningless items that the delusional spend their money on....And that is the reason I use the place...not to mention that my speakers are rather good...

Mate, I'm stunned that you and the other pseudo scientists aren't willing to try. You haven't even looked at the web page, have you? It makes the point about playback equipment, which is why you have to download the files.

Closed minds are one thing, but what are you afraid of? That, if you take the blind tests, you can hear the difference? Surely, as a believer, you should be excited by that, because then you guys are going to have to work out why, and, in doing so, make an active contribution to the science rather than just spouting the familiar stuff about half-understood theories.

I thought experiment was a part of science, but obviously you guys are never taught to question. You can learn how to swim by reading all the textbooks in the world, but, in the end, you have to jump into the water to prove them right.

 

[chebby]

Lets put this 13 bit 32k sample rate to the test then. Make a recording at -75dbs to -45dbs at this sample rate and compare it to a 15ips tape recording of the same performance at -30dbs to -0dbs to see if 13 bit really does have usable dynamic range of 78dbs.

13 bits gives us 8192 different possible values.

No. Can you tell me (better still BBC engineering and R&D and Siemens) where they were either lying, mistaken or getting it all wrong. (Especially as they weren't in the business of propagating marketing BS to sell consumer goods. In the 1970s - long before the internet and online archives - you couldn't even find this stuff unless you worked for the BBC.)

 

[steve_1979]

Mate, I'm stunned that you and the other pseudo scientists aren't willing to try. You haven't even looked at the web page, have you? It makes the pointabout playback equipment, which is why you have to download the files...

For it to be a scientifically fair and valid test you first need to convert the high rez file to 16/44 yourself before doing a 'blind' comparison to ensure that they are both from the same mastered version of the track. Otherwise any differences that you hear may be down to the two different mastering versions which has nothing to with the bit rate.

 

[Sliced Bread]

I can't talk 16 bit vs 24 bit music due to lack of experience comparing the same material on the same hardware, but what's people's opinion of dvd's (just below cd quality) sound and bluray lossless encodes, which are supposedly 24 bit, bit in most cases actually 16 bit.

Few people would deny that the bluray is appreciably better (even if it is still 16 bit), which brings me to my point:

So many cd's on the market sound rubbish, either due to poor recordings or just because of low bit-rates. 24 bit or should that be "24" bit are aimed at people looking for the best possible quality and therefore a higher bit-rate is used rather than the putting a track on a cd which is not using cd to its fullest ability.

That maybe the difference people are hearing. Record labels, for the most part are providing us with a lot of junk by squeezing a thousand tracks on a cd, especially for music compilations. It's kind if like the picture on DVD and DVD superbit.

This maybe also why downsampling a 24 bit track at home to 16bits shows little (if any) difference as the 16 bit recording is about as good as it can get.

So maybe *some* 24 bit encodes sound better, not because 24 bit is needed but because the 16 bit cd is just not making the most out of the format.

 

[Alec]

obviously you guys are never taught to question.

What-what?

 

[namefail]

obviously you guys are never taught to question.

What-what?

...yes?

 

[steve_1979]

Could I respectfully request that anyone reading/commenting about 16/44.1 CD quality audio reads about and understands Nyquist-Shannon theory first?

Nyquist-Shannon theory is used to to perfectly reproduce any analogue wave within the limits of human hearing from 16/44.1 digital information. But without fully understanding how Nyquist-Shannon theory works then using it to convert a limited number digital bits into a perfectly reproduced analogue wave is going to seem counterintuitive to you.

 

[Alec]

No, you can't request that people understand something, in that sense.

 

[steve_1979]

No, you can't request that people understand something, in that sense.

True.

But what I fail to understand is why people try to debate a subject if they don't understand how it works?

 

[Alec]

No, you can't request that people understand something, in that sense.

True.

But what I fail to understand is why people try to debate a subject if they don't understand how it works?

Unknown unknowns.

 

[namefail]

Was it not meant rhetorically?

 

[altruistic.lemon]

Mate, I'm stunned that you and the other pseudo scientists aren't willing to try. You haven't even looked at the web page, have you? It makes the pointabout playback equipment, which is why you have to download the files...

For it to be a scientifically fair and valid test you first need to convert the high rez file to 16/44 yourself before doing a 'blind' comparison to ensure that they are both from the same mastered version of the track. Otherwise any differences that you hear may be down to the two different mastering versions which has nothing to with the bit rate.

Mate, read the bloody website!

 

[Alec]

Was it not meant rhetorically?

What if this weren't a rhetorical question?

And just what was meant by "you guys"?*

*Not a rhetorical question.

 

[namefail]

Was it not meant rhetorically?

What if this weren't a rhetorical question?

And just what was meant by "you guys"?*

*Not a rhetorical question.

I think the you guys thing is a paranoid invention that there’s a shadowy cabal mounting efforts against him. Defo Dog.

 

[steve_1979]

Was it not meant rhetorically?

No. It was ment literally.

Without understanding Nyquist-Shannon theory it's difficult to appreciate why it's possible to perfectly reproduce any analogue wave from a limited number of digital bits. IMO it's peoples lack of understanding of how Nyquist-Shannon theory works which is the cause of these high rez vs 16/44 forum debates.

 

[steve_1979]

Mate, read the bloody website!

I've read the link that you posted but I'm not really sure what point you're trying to make.

Like I said earlier: for it to be a fair and valid scientific test download the high rez versions and convert them to 16/44.1 yourself before doing the 'blind' comparisons. By doing it this way you can be sure that the only variable is the bit-rate.

The high rez and 16/44.1 versions will sound the same.

 

[altruistic.lemon]

Was it not meant rhetorically?

No. It was ment literally.

Without understanding Nyquist-Shannon theory it's difficult to appreciate why it's possible to perfectly reproduce any analogue wave from a limited number of digital bits. IMO it's peoples lack of understanding of how Nyquist-Shannon theory works which is the cause of these high rez vs 16/44 forum debates.

Read the website yet? Explains why your previous answer was way off.

Why don't the AVI pack stick to their own forum? They can't handle people even thinking questioning their wisdom, which makes for pretty stupid threads.

What really p*sses me off is the website I posted would probably backup their beliefs, not destroy them, yet they see it as a threat.

 

[Alec]

Was it not meant rhetorically?

No. It was ment literally.

Without understanding Nyquist-Shannon theory it's difficult to appreciate why it's possible to perfectly reproduce any analogue wave from a limited number of digital bits. IMO it's peoples lack of understanding of how Nyquist-Shannon theory works which is the cause of these high rez vs 16/44 forum debates.

Read the website yet? Explains why your previous answer was way off.

Why don't the AVI pack stick to their own forum? They can't handle people even thinking questioning their wisdom, which makes for pretty stupid threads.

What really p*sses me off is the website I posted would probably backup their beliefs, not destroy them, yet they see it as a threat.

Some of "them" were here before they were there, and have been here for years, and some who agree with them may not even have been there. You really do need to think about what you're saying.

Anyway, "you guys"?

 

[altruistic.lemon]

Mate, read the bloody website!

I've read the link that you posted but I'm not really sure what point you're trying to make.

Like I said earlier: for it to be a fair and valid scientific test download the high rez versions and convert them to 16/44.1 yourself before doing the 'blind' comparisons. By doing it this way you can be sure that the only variable is the bit-rate.

The high rez and 16/44.1 versions will sound the same.

For f$kcs sake, they're test tones!!! Do you think the bloody mastering will be different??