What is Hi Res Audio?

[Naturelover]

Yes, that was the innocuous title of three mails that I received from one who would know what he's talking about. These are from Jochen of "The Listening Room" in Bangalore. Some other forum members might also have received them.

Here goes:

MAIL 1

Often, when I talk to my customers about High Resolution or High Definition Digital Audio I'm getting the impression that there is a lot of misunderstanding about this topic. Therefore let me try to clarify a bit.

1) High Res or HD music files is music recorded, mixed and mastered entirely in the digital domain at 24bit/96kHz or higher.
1.1) Digital PCM recordings, if done well at 24bit/96dB, can have a dynamic range of up to 130 dB. This equals the capability of the human hearing capacity (130 dB = threshold of pain).
1.2) Digital recordings done at 24bit/96dB or higher contain ultra sonic frequencies up to 48 kHz, which, as we all know, do play a great role in the fidelity, resolution and openness of recorded music.

2) Music that was recorded, mixed and mastered in the analog domain and then converted to digital 24bit/44.1kHz or higher does not qualify for being High Resolution or High Definition.
2.1) Because of it's limitation in dynamic range to approx 65 dB analog tape can deliver only half the dynamic range of a High Res/HD recordings done at 24bit/96kHz or higher and therefore does not qualify being of High Resolution/High Definition.
2.2) Bandwidth of analog tape is limited to approx. 20 kHz and does not contain ultra sonic frequencies like 24bit/96kHz (or higher) recordings, and therefore does not qualify to be of High Resolution/High Definition.

3) Music that was recorded, mixed and mastered in the digital domain but at 16bit/44.1kHz (standard CD-quality) and then converted to digital 24bit/44.1kHz or higher does not qualify for being of High Resolution or High Definition.
3.1) Because of it's limitation in dynamic range to approx 90dB digital files of standard resolution (16bit/44.1kHz aka CD-quality) can not deliver the dynamic range of High Res/HD recordings at 24bit/96kHz or higher and therefore do not qualify being of High Resolution/High Definition. It is only standard resolution.
3.2) Bandwidth of standard resolution recordings (CD-quality) is limited to 22.05 kHz and does not contain ultra sonic frequencies like 24bit/96kHz (or higher) recordings, and therefore do not qualify to be of High Resolution/High Definition.

Presently all the major record companies are converting their back catalogues to 24/44.1, 48, 88.2, 96 or 192 files and call them High Res or HD Music Files. This is absolute nonsense and not genuine, because most of these back catalogue recordings were either recorded, mixed and mastered on analog tape or to digital but at standard resolution CD-quality (16/44.1). And because of the shortcoming over genuine native High Resolution/High Definition digital recordings, those files cannot be called High Res or HD. So be aware when you download such music files. These are just as good as a CD, nothing more! The only difference to a CD or LP is, that
a) the vendors charge you an extra premium for being High Resolution/High Definition, which is a lie but big business for the vendors and record companies
b) the extra large file size only crowds your hard disk with empty zeroes and ones without any additional information.

Try to locate genuine, native High Resolution/High Definition Music Files and buy these.....it's worth it!

MAIL 2
After the above, I got a lot of responses thanking me for this clarification. Still some were confused about what is and what is not High Resolution or High Definition (both the terms are still used and no decision how these new formats should be called is made). So I have prepared a chart

listing all the formats in the 3 categories (low, standard and high resolution/definition). Still quite confusing. But when you filter out the most commonly used formats, which are MP3, Vinyl, CD, and PCM downloads at the different sample rates, it becomes a bit clearer. I hope this clarifies even further.


MAIL 3
In June 2014 the Japan Audio Society (JAS) has published a list of what actually defines High Res Audio productions to adopt Sony's High Res Audio Logo.

You would have all seen this logo somewhere on download sites:

And there is the list published by JAS:

This clearly confirms what I had written in my post before. That the whole recording process must take place in the digital domain using a format of 96kHz/24bits or above.
And the equipment used must be able to capture and transmit frequencies of 40 kHz or above.

That means only high bandwidth amplifiers qualify for being capable of transmitting HD-Audio. Conventional tube amps with their bandwidth limiting output transformers certainly do not qualify, except OTL tube amplifiers because these do not use output transformers.

Further it is interesting to see that the DSD (Direct Stream Digital) format finds no mention in this list. Why? Because commercial recordings, that are all mixed, edited and mastered, cannot be made in the DSD format. For mixing, editing and mastering the DSD file has to be converted into the analog or PCM domain, and then converted back to DSD for distribution. As we know analog is not high resolution, it is standard resolution. And converting a standard resolution file to DSD does not improve its fidelity and give you more detail and resolution.
When converting DSD to PCM for mixing, editing and mastering and then converting it back to DSD the fidelity also does not improve, because the dynamic range of DSD is limited to 99 dB only and therefore does not qualify for High Res. The dynamic range that PCM can deliver is 130 dB... the dynamic range of human hearing. The only way to get High Resolution from DSD is using 11.2 MHz/1bit DSD, convert it to DXD (352.8 or 384 kHz PCM) for mixing, editing and mastering and then convert it back to High Res DSD. It's a method used by the audiophile label 2L and a few others. But those recordings are very very rare. And this method will certainly never be used for commercial recordings.

I have reworked the chart of my last post a bit.

 

[Thad E Ginathom]

High-res, high definition... purely marketing terms, climbin on the back of something that is probably real in video. Industry-created, they are not technical terms.

High sample rate and High bit rate might be more accurate, but even then, high[er] than what? What's so low about 44.1k? The sample rates that telephones work at: that's low!

Of course, if you ask the industry that is selling this stuff, you get different answers.

And yes, I came to this conclusion in my armchair





...with the headphones on :lol:

 

[Naturelover]

Thad, have you tried native hi res files or only so-called hi res from old recordings?
This from Jochen:

should once hear a true, genuine and native high resolution track, especially with his headphones on, because a good head phone's frequency range extends to something around 40 kHz. I'm sure he will change his opinion.

But, then, what with your HF hearing issues, this might not be applicable :sad:

 

[kvm]

Thx Naturelover for the useful post. BTW are there any 'legal' avenues to obtain samples/ purchase native Hi-res audio to get the real feel? I know HDtracks doesn't sell internationally yet!

regards

 

[jagdish_p]

Have any of the FMs heard true High Resolution audio as described above?
Will appreciate if they can share their listening experience and the names of the albums. And importantly the system used for playback. Thanks.

 

[Naturelover]

Difficult to say if you can find by searching native hi res files. I haven't tried.
HD Tracks does sell internationally through PayPal. I have bought a couple of albums.

.. are there any 'legal' avenues to obtain samples/ purchase native Hi-res audio to get the real feel? I know HDtracks doesn't sell internationally yet!

 

[kvm]

Thx for the response. Surprised. Recently they replied that they do not sell outside US 'yet'.. also could you download from indian IP addresses?

pasting below their response:
------------
Hi

Please note, you are outside the U.S. We currently are not available internationally. This is due to record label restrictions on high res digital downloads. We are seeking to launch internationally soon. But at this moment I do not have an exact time period.


Sincerely,
Stephan
HDTracks Support Team@
Homepage | HDtracks - The World's Greatest-Sounding Music Downloads
--------------
anyways paypal is another hindrance

 

[Naturelover]

Yes, I got the same response but read on this forum itself that the Paypal route was possible. I have downloaded on my PC here at Nagpur with a BSNL account.
I don't look at PayPal as a hindrance. Quite the opposite, in fact. I have used it a few times for other purchases as well. Very convenient, really.

Thx for the response. Surprised. Recently they replied that they do not sell outside US 'yet'.. also could you download from indian IP addresses?

pasting below their response:
------------
Hi

Please note, you are outside the U.S. We currently are not available internationally. This is due to record label restrictions on high res digital downloads. We are seeking to launch internationally soon. But at this moment I do not have an exact time period.


Sincerely,
Stephan
HDTracks Support Team@
Homepage | HDtracks - The World's Greatest-Sounding Music Downloads
--------------
anyways paypal is another hindrance

 

[Thad E Ginathom]

Thad, have you tried native hi res files or only so-called hi res from old recordings?
This from Jochen:

should once hear a true, genuine and native high resolution track, especially with his headphones on, because a good head phone's frequency range extends to something around 40 kHz. I'm sure he will change his opinion.

But, then, what with your HF hearing issues, this might not be applicable :sad:

Well, if we are talking 40k, then everyone has HF hearing deficiency, by definition! Even 20k is an optimistic limit to human hearing for anyone past their teens. And before any sound gets to the speakers or 'phones, we have to ask if the equipment it is coming from is capable of handling these unhearable-anyway frequencies. Why are people not just laughing at all this stuff?

But yes, I spent a few hours, some years ago, comparing the same music at different sample-rates. Every time I heard a "difference" I would find the same thing in the other examples. Every time, without fail.

So how many people have come to the conclusion that high-sample-rate music is wonderful without comparing, very critically, and preferably blind, with the same thing at lower sample rates? That would be easy: I have some superb 96k music, but I don't have the same at 44.1, and every time I think that the superbness might be related to the "96" I remind myself that I have lots of superb 44.1k music too!

As mentioned in another thread: there has not been a double-blind test in which people could tell the difference. We can be sure that is true, because if and when there is, and it has been subjected to the very critical assessment that such a result would get, the industry will shout it from the roof tops. And I and many others will happily say, ok, we (and some of the great scientists and technical people without whom we would not even have this digital music) were wrong. I don't care: I have 96k and even 192k files on my hdd, and it would be nice if there was actually a point to them.

All this stuff is such a huge waste of money, energy and resources. There is a big body of opinion that says that the biggest improvement in sound would come from better recording techniques, and better mastering. At the consumer end we could be getting better equipment, better speakers. Instead, the industry is taking the easy path of bigger numbers, and trading on the misuse and misunderstanding of "resolution" and "definition."

It's almost enough to drive a man back to vinyl hyeah:

 

[Ambio]

..Referring to the logo...

Here is another one using FPI .

Have any of the FMs heard true High Resolution audio as described above?
Will appreciate if they can share their listening experience and the names of the albums. And importantly the system used for playback. Thanks.

You can use JRiver or Foobar. I am not familiar with Foobar. In JRiver the default recommended filter setting for HD files is 22kHz to prevent damage to equipment. I use Mytek and bypass JRiver internal processing and set MYtek's filter to 50kHz (the lowest).

As I have mentioned elsewhere in this forum, the best audio quality that I have are recordings form L2 and Blue Coast. You can get some info here. Click on the Music services. Having said that, I could happily accept CD quality as good enough. Try here and click the store for test bench files.

 

[prem]

Steve Hoffman is considered one of the better mastering engineers of our time.

Here is his take on what sounds closest to the master tape

SH Spotlight - What sounds just like the master tape: CD, Vinyl, SACD or an Open Reel tape copy? | Steve Hoffman Music Forums

 

[Thad E Ginathom]

There is a lot of fascinating stuff by some very famous names on this, and related subjects, out there on the net. Two names (amongst many) that come to mind from my browsing on Gearslutz and other places are Paul Frindle (Digital mixing pioneer. And he has some interesting and controversial stuff to say about audible stuff that shouldn't be, too) and JJ Johnston (digital pioneer, co-inventor of MP3). Not to ignore relative youngsters, either: without Monty Mongomery and colleagues we would not have FLAC or OGG.

Specifically, without JJ and Monty's writings, my understanding of digital audio would still be hitting the brick-wall filter of... mathematics. It is one thing to be completely literate/numerate in these things, and quite another to be able to explain them, at least as far as possible without the formulae, to those of us who are not.

Interestingly, JJ does not, it seems, think that 44.1 was the right choice.