24/96...24/192 query

Posted by: Jon Myles on 29 June 2012

Another query....following on from one as to where the artwork on NAS files was sourced from when transmitted to a control point.

File info: Do the Naim streaming products 'read' the actual file to determine whether it is 44.1/96/192 etc - or do they take this information from metadata?

I'm assuming it's the former. On my iPhone various files show different values: But where is this value coming from in the software? I'm having to take it that the streamer is reading the files, assessing the value and then retransmitting that to the control point (ie: iPhone/iPad/iPod Touch).

Or is it just reading the metadata attached to the files?

I'd like to know as in the future it could make quite a difference to my purchasing. And my understanding as to how the whole set-up works.

Posted on: 29 June 2012 by winkyincanada

Serious question - why does it matter? I'm not sure I understand how it would make "quite a difference" to your purchasing.

Posted on: 29 June 2012 by Jon Myles
Originally Posted by winkyincanada:

Serious question - why does it matter? I'm not sure I understand how it would make "quite a difference" to your purchasing.

Fair question: Only in the sense as to would it actually be 24/96 or just labelled as such?

A little bit like the old 'remastered', 'gold' etc CDs.

Obviously, my ears are the final arbiter. But I can see the possibility of tracks being labelled 24/96, 24/192 which are, actually, not of that quality.

Posted on: 29 June 2012 by Foxman50

Jon

 

Im pretty sure Naim just reads the meta data attached to the file.

Posted on: 29 June 2012 by Jon Myles
Originally Posted by Foxman50:

Jon

 

Im pretty sure Naim just reads the meta data attached to the file.

Hi Foxman

 

Indeed. That's what I thought.

Not a great problem....but with the rash of 24/96 issues starting to grow I could see the potential for some record company rehashes here. After all, they'll have to take time to get these 24/96, 24/192 reissues right.........or do they if all they have to do is change metadata on a download?

Paranoid...me?

Posted on: 29 June 2012 by Foxman50

Read the reports on HDTracks doing just that. Allegedly of course To be fair i think they repackage it in a 24/96/192 container. But if its CD quality to start with its CD quality full stop.

Posted on: 29 June 2012 by Aleg
Originally Posted by Jon Myles:
Originally Posted by Foxman50:

Jon

 

Im pretty sure Naim just reads the meta data attached to the file.

Hi Foxman

 

Indeed. That's what I thought.

Not a great problem....but with the rash of 24/96 issues starting to grow I could see the potential for some record company rehashes here. After all, they'll have to take time to get these 24/96, 24/192 reissues right.........or do they if all they have to do is change metadata on a download?

Paranoid...me?


That can't work like that.

 

It wil determine the sample rate from the settings in the audio part of the file and not from the meta-data tags,  otherwise it cannot play it properly as well.

 

So no easy shortcuts for malafide record dealers/companies, by just editing metadata tags.

 

What they could easily do however is just upsample a low-res to a high-res format and  it will be processed and shown as a high-res. There have been some examples of this malafide practice, but these dealers will suffer massive damage to their credibility and some still suffer from that from errors made several years back.

 

It would require some analysis of the audio data to see if it is a genuine high-res and not an upsampled low-res and that's not easy to do for the ordinary 'Joe the plumber'. For example using something like Spek – Acoustic Spectrum Analyser.

 

Posted on: 29 June 2012 by Foxman50

Aleg that's kinda what i meant. You can upsample all you want but you cant create data from nowhere. HIFi news have reported this on numerous occasions from numerous vendors. Buyer beware. Hopefully the likes of LInn and Naim are more fastidious.

However the original question, unless i miss understood was how to Naim products show the sample rate and i believe it comes from the meta data. But as winky said who cares. Surely its what it sounds like that matters

Posted on: 29 June 2012 by Jon Myles
Originally Posted by Foxman50:

Aleg that's kinda what i meant. You can upsample all you want but you cant create data from nowhere. HIFi news have reported this on numerous occasions from numerous vendors. Buyer beware. Hopefully the likes of LInn and Naim are more fastidious.

However the original question, unless i miss understood was how to Naim products show the sample rate and i believe it comes from the meta data. But as winky said who cares. Surely its what it sounds like that matters

 

Pretty certain Naim and Linn are more fastidious. No worries there.

I was just looking to the future. If higher resolution is to catch on and become the norm outside the hi-fi community (which I hope it will) then sharp practices like those outlined in other posts here won't help.

People will just say: "Sounds the same as CD to me."

As you say Foxman, it's the sound that matters. Just be nice to have more people here that sound. It benefits us all.

Posted on: 29 June 2012 by Foxman50

For me the issue isn't the bit rate its the quality of musicianship and recording. Why is it so many hi res files are remastered. Is it the fact that CD has enough resolution to convey all the detail required. But they have to remaster the album to get a different sound, and by doing so we feel we are getting something extra. I'm not an engineer to know the answer, but i do know i have some pretty good CD rips running through my ND5.

Posted on: 29 June 2012 by Simon-in-Suffolk

Jon, the information is in the header part of the WAV or FLAC file. The header contains the number of channels, sample rate and sample word size - but this is completely unrelated to any metadata that may also be in the file. The file reader uses this header machine readable information to then correctly decode the sample DATA part of the file.

With WAV, the old fasiohioned version of the file, sometimes called the canonical version, had a header construct that could not reliably define the parameters for multichannel or hidef, and so a new version was created around 10 years ago called the 'extensible' wave file. This file supports hidef and standardised INFO meta data etc. This is the version that Naim and dBPoweramp use for example, but not Apple iTunes which for some reason uses the older version that can only reiably support upto two channel 48kHz 24 bit data (at least it did 12 months ago when I reverse engineered the Apple files)

Posted on: 29 June 2012 by Jon Myles

Thanks Simon.

That explains for it me. I like to know what I'm talking about!

 

Cheers

 

Jon