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

[oldric_naubhoff]

24 bit download have very limited availbility and cost considerably more.

patience patience. all in it's time. I gather it won't be too long for hi-res audio to retain its luxury goods sticker since most of the far-east big boys already grasped the idea of promoting it.

 

[oldric_naubhoff]

DSP engines run at higher bit depths to allow the calculations to take place without truncation. It is perfectly reasonable to have a DSP engine with 16 bit input and output, but to perform calculations in 24 (or higher) bits.

can you confirm, or deny, that 24 bit audio file downconverted to 16 bit audio file and then upconverted again to 24 bit audio file (in another device, using possibly a different upconverting algorithm to the one used in downconversion process) will be the same 24 bit audio file as the original 24 bit audio file?

 

[NHL]

DSP engines run at higher bit depths to allow the calculations to take place without truncation. It is perfectly reasonable to have a DSP engine with 16 bit input and output, but to perform calculations in 24 (or higher) bits.

can you confirm, or deny, that 24 bit audio file downconverted to 16 bit audio file and then upconverted again to 24 bit audio file (in another device, using possibly a different upconverting algorithm to the one used in downconversion process) will be the same 24 bit audio file as the original 24 bit audio file?

Some info from Ayre:

http://www.ayre.com/insights_dsdvspcm.htm

 

[fr0g]

So 'using your ears' misses the point of hifi entirely?

No , it misses the point of "this thread".

Since this illustrates your complete non-understanding of even the most basic concept of how speakers work, maybe you ought not to be calling anyone a dimwit (you know, the kettle black and all that). And perhaps, you ought to master the basics of hifi before wading with such marked arrogance into a debate about the complexities of digital reproduction and the nature of human hearing. Since you don't even know what a three-way speaker is.

Oh, I know full well that each speaker is filled with tiny faerie folk. Cheap speakers might only have a couple of duets, and if they are really cheap, a couple of drunk hobbits from Tottenham, whilst big whopping expensive ones have whole harmonic choirs of royal Welsh elves. That is why they sound better...Doesn't everyone know that?

 

[Anonymous]

That would be "Grammar"

He did that especially for you.

 

[Anonymous]

Oh, I know full well that each speaker is filled with tiny faerie folk. Cheap speakers might only have a couple of duets, and if they are really cheap, a couple of drunk hobbits from Tottenham, whilst big whopping expensive ones have whole harmonic choirs of royal Welsh elves. That is why they sound better...Doesn't everyone know that?

Your signature says:

"Out beyond ideas of wrong and right, there is a field.

I'll meet you there."

I think your brain left the building.

 

[CnoEvil]

- Has anyone changed their mind as a result of this thread?

- After 350+ posts, has the original question been answered?

- Has anything new been uncovered?

- Are y'all any the wiser?

- Maybe when we do it all over again in a couple of months, we'll find the way out of the maze.

 

[steve_1979]

- Has anyone changed their mind as a result of this thread?

Not me. But I now have a better understanding about the noise floor and and it's significance (although I already understood before that the noise floor on 24 bit audio is lower than on 16 bit audio but that it's still well below what's audible with 16 bit so that it's not an issue where playback purposes are concerned).

- After 350+ posts, has the original question been answered?

IMO no. To answer fr0g's original question I haven't seen any concrete, scientific evidence in this thread which shows that 24 bit audio has any advantage (for playback use) over 16 bit audio.

- Has anything new been uncovered?

That depends who you ask. There are probably loads of people reading which have learned something new from this thread.

- Are y'all any the wiser?

I've learned a bit about digital audio, microphones and surprisingly bats.

- Maybe when we do it all over again in a couple of months, we'll find the way out of the maze.

A couple of months before the next one? You're being optimistic if you think it'll take that long.

 

[andyjm]

DSP engines run at higher bit depths to allow the calculations to take place without truncation. It is perfectly reasonable to have a DSP engine with 16 bit input and output, but to perform calculations in 24 (or higher) bits.

can you confirm, or deny, that 24 bit audio file downconverted to 16 bit audio file and then upconverted again to 24 bit audio file (in another device, using possibly a different upconverting algorithm to the one used in downconversion process) will be the same 24 bit audio file as the original 24 bit audio file?

I am not sure as to the reason for your example, but of course it won't be the same. If you start with 24 bits, throw 8 of them away, you won't be able to get the original 24 bits back.

My example was the opposite. Start with 16, do some clever maths at 24, then back to 16 for the output. Much of DSP processing involves multiplying samples by factors and adding the results. To give a very basic example, if you have a 16 bit number and multiply it by 2 you need 17 bits to store the result. Add in another sample and you need 18 bits. If you don't have the headroom then your only alternative is to truncate the maths which leads to distortion.

 

[shadders]

Using the DSP books i have - specifically the Sampling and Reconstruction of Signals

what books that may be? I'm no engineer but keenly interested in all things audio and why is that it all works. I think reading through articles available on the net brought me to a point where I won't learn anything new and I know I still know very little. I guess a comprehensive book on DSP woul likely quench my thirst for knowledge on the matter.

Hi,

The book i used was Digital Signal Processing by Proakis and Manolakis, 3rd Edition - it is quite mathematical.

For an appreciation - i think the DSP manufacturers such as Analog, Texas Instruments, or possibly Freescale provide some free texts.

http://search.analog.com/search/default.aspx?query=audio%20tutorial&local=en

If you select training and tutorials on the left hand side - then you can download some documents.

Texas Instruments seem to provide less - but i have not really searched. Not sure about Freescale.

A reasonbly easier to understand book is an Analog Devices book called Mixed-Signal and DSP Design Techniques - this is possibly a collection of papers from the Analog site - Newnes publish this book.

Elektor provide some good "hands on" tutorials - you generally have to buy their kits - but these are much cheaper than a DSP manufacturers development kit, and based on free software from the semiconductor.

There are other books - but you cannot eliminate the maths - so the analog devices book is probably the best.

Regards,

Shadders.

 

[matt49]

To answer fr0g's original question I haven't seen any concrete, scientific evidence in this thread which shows that 24 bit audio has any advantage (for playback use) over 16 bit audio.

Unusually, I'm with you on this one, Steve, although I'd add that I think I now have a clearer understanding of why hi-res is (or might be?) preferable for mastering.

I've learned a bit about digital audio, microphones and surprisingly bats.

You mean you didn't know bats have golden ears?

On a semi-serious note, when I had a home demo of the Harbeth SHL5s last summer, my dog reacted very strongly to the sound, which I put down to the super-tweeters.

:O

Matt

 

[shadders]

Hi,

I ordered so far 4 high resolution audio blu-ray disks - but they are not replacements for albums i already have. As such i can state that they sound different to CD - they are more open and lighter / airy - compared to a standard CD.

I have an Audiolab 8200AP and Cambridge Audio 650A amplifer - transmission line speakers - so reproduction is very good.

The instrument placement is accurate (assumed) - and vocals well defined.

I have the Elbow CD Build a Rocket Boys - and this really does sound very good on my system - so i can only derive that the mastering and production on this album was carefully implemented.

The high res audio people seem to be releasing some old ablums - which are not very popular - but the Tears for Fears - Hurting - album does sound good - certain you can hear the analogue tape hiss.

Regards,

Shadders.

 

[Paul.]

- Has anyone changed their mind as a result of this thread?

I have changed my mind. I have gone from "I think I understand this" to "I don't think I understand this" :rofl:

 

[steve_1979]

I've learned a bit about digital audio, microphones and surprisingly bats.

You mean you didn't know bats have golden ears?

jcbrum said "Some bats can squeak very loudly, - over 130dB."

What a racket. I'm glad that I can't hear it.

 

[CnoEvil]

- Has anyone changed their mind as a result of this thread?

I have changed my mind. I have gone from "I think I understand this" to "I don't think I understand this" :rofl:

Just keep repeating to yourself: Everything sounds the same......Everything sounds the same........Everything sounds the same......... :wall:

 

[davedotco]

- Has anyone changed their mind as a result of this thread?

I have changed my mind. I have gone from "I think I understand this" to "I don't think I understand this" :rofl:

That is progress, of a sort.

It closely mirrors my own view which can be summed up as.....

"The moment you really think you are beginning to understand digital audio, you are almost certainly wrong".

 

[davedotco]

- Has anyone changed their mind as a result of this thread?

I have changed my mind. I have gone from "I think I understand this" to "I don't think I understand this" :rofl:

Just keep repeating to yourself: Everything sounds the same......Everything sounds the same........Everything sounds the same......... :wall:

Now, now Cno, nobody is actually saying that.......... :doh:

As I am sure you know, from personal experience, some (many?) hi-res recordings from (say) Linn sound 'better' than their CD equivilents.

This thread has, for me, rationalised to the following dillema.......

Is the improvement brought about by the format change or is their another reason.

Followed by the question, is there a rational way that we can carry out comparisons to find out which is most likely.

I proposed a test where a 24/96 file of known quality is downsampled to 16/44.1 and compared directly with the other file. This is not that dificult to do using software (Audacity) or a third party to perform the switching.

An individual carrying out this test is not rigorous in a scientific manner, so it will not 'prove' anything, but interesting enough if you can be bothered to try it.

 

[CnoEvil]

It closely mirrors my own view which can be summed up as.....

"The moment you really think you are beginning to understand digital audio, you are almost certainly wrong".

That sums it up for me as well.

 

[CnoEvil]

Now, now Cno, nobody is actually saying that.......... :doh:

:shifty:

 

[davedotco]

Now, now Cno, nobody is actually saying that.......... :doh:

:shifty:

Careful Cno, you might be letting a sense of humour show through.

You know that on this forum, that is going to end badly.........

 

[matt49]

I've learned a bit about digital audio, microphones and surprisingly bats.

You mean you didn't know bats have golden ears?

jcbrum said "Some bats can squeak very loudly, - over 130dB."

What a racket. I'm glad that I can't hear it.

Yes, fortunately you're safe. If you were a hamster or gerbil, you might be able to hear the bats, though the ultrasonic 'calls' of bats tend to be rapid pulses rather than continuous tones, and so I reckon the gerbils aren't too bothered.

 

[the record spot]

Guys, it's just another format. That's it. They're busy touting Blu-ray audio (or Pure Audio) now and selling titles for around £15 and upwards. I'm very suspicious of it all; it's always, always going to be production and mastering first. In fact, just mastering. Nirvana's "Nevermind" album's not been remastered and it's a killer disc. Absolutely killer.

EMI/Virgin have stuck out another copy of Selling England By the Pound by Genesis on Blu-ray audio. Great album though it is, they've stuck out the 2007 mix which is a f****** mastering travesty. Yours for £18. I've got the original disc from the 80s and it blows it away.

These advances have been touted for long enough, probably since Edison produced his gramophone. 24-bit is being sold on left, right and centre. HD Tracks offer downloads, music is produced on 24-bit, AVI use a 24-bit DAC on their 9.1RS speakers, my Onkyo has a Burr-Brown 24-bit DAC on it. And so on and so forth.

The format is by and large irrelevant, much like the discussions, or at least, yet another discussion about the topic...

 

[Tonestar1]

However, If you would like to discuss hi-fi on a hi-fi forum I don't think complaining about how boring and circular a thread may be is very constructive, it just exacerbates the issue , neither is belittling other forum members for posting information they may think is a genuinely new contribution to the discussion. If you find a thread dull, worthless or past it's sell by date then don't comment on it, simple as that.

Ah, the old 'no-one's forcing you to read it' argument, huh?

Yes, I'd love to discuss hi-fi on a hi-fi forum. Do you know of any I could try? ;-) The personal combat here is taking things further and further away from that.

Seriously, though, this isn't a discussion about hi-fi, just like the endless threads about cables, active/passive speakers and other topics have little to do with the music and how it's played. Like those threads, this one has far too much w1lly-waving, far too much backstory for that, and that's a bit sad.

You seem to have missed the point. Which was, don't contribute if you have no interest in the thread or more importantly, nothing to contirbute to it. I'm not supporting the "if you don't like it, dont read it" theory you prospose... thats insanity. How would you possibly know your postion on a thread if you haven't read it?

I also get bored by lots of threads on here, mainly around tv's and cables. I have no need to comment as I have little interest in the outcome. I onlt choose to comment on threads i feel I can add to or provide a logical argumeant against.

“Never argue with an idiot. They will only bring you down to their level and beat you with experience.”

I'm not excluding myself from the quote above

ps typing this on my phone so please dont hammer me for spelling mistakes or grammatic errors

 

[spiny norman]

You seem to have missed the point. Which was, don't contribute if you have no interest in the thread or more importantly, nothing to contirbute to it.

And you seem t have missed my point, which is that I am interested in the topic of the thread, but not the endless round of 'Oh yes is it'/'Oh no its isn't' it has become. Like so many threads where there's a vested interest involved, it's a bit like Formula 1 these days: the start's a bit exciting, but by the time we've been round the track a few times it gets dull and repetitive, simply because nothing new's happening, just stuff we've all seen before.

ps typing this on my phone so please dont hammer me for spelling mistakes or grammatic errors

Why would anyone do that?

 

[NHL]

You seem to have missed the point. Which was, don't contribute if you have no interest in the thread or more importantly, nothing to contirbute to it.

And you seem t have missed my point, which is that I am interested in the topic of the thread, but not the endless round of 'Oh yes is it'/'Oh no its isn't' it has become. Like so many threads where there's a vested interest involved, it's a bit like Formula 1 these days: the start's a bit exciting, but by the time we've been round the track a few times it gets dull and repetitive, simply because nothing new's happening, just stuff we've all seen before.

ps typing this on my phone so please dont hammer me for spelling mistakes or grammatic errors

Why would anyone do that?

Essentially, this forum needs more active moderation. The long threads always ends up like this.