Head-Fi.org › Forums › Equipment Forums › Sound Science › Testing audiophile claims and myths
New Posts  All Forums:Forum Nav:

Testing audiophile claims and myths - Page 163

post #2431 of 3264
Quote:
Originally Posted by cswann1 View Post
 

Wow.  What a fantastic video. Very informative.

 

I've never stressed over bit-rates because I've never been able to tell the difference between my Nora Jones - Come Away With Me SACD and the standard redbook. Now I have a solid explanation of why that is, I mean other than the fact that I don't have superduperuberaudiophile hearing.

That video cracked me up - like VERY few things can. The exact immediate association, if posted, would get me banned in an instant - but suffice to say is that it is very cunningly hiding ( or completely non-understanding  ? ) what it really is all about. Nothing wrong with the presentation etc - but it IS too superficial and misleading to those who are not familiar enough with measurements and/or audibility of certain parameters on QUALITY audio equipment using QUALITY recordings.

 

I do not know Nora Jones either on redbook or SACD - getting her firs LP is still something better forgotten sooner than later. It was not a good recording - enjoyabe yes, good - NO.

 

There is at least one label with consistently high enough sound quality to justify getting AUDIBLY better than CD version. Opus 3 from Sweden. All were  originally recorded to analog tape, using minimalistic microphone setups. Personally, I am the most familiar with the http://www.discogs.com/Omnibus-Wind-Ensemble-Music-By-Frank-Zappa/release/1820934 . It exists as original analog LP ( sadly, I was too late to get it at anything resembling sensible price ), CD and lastly, SACD/CD version. 

It is HORRIBLE how much better the last polycarbonate version sounds compared to initial CD release - even on CD layer.  Switch your player to SACD  - MUCH better still. Opus 3 is now offering DSD downloads of most of its catalog - http://www.opus3records.com/ About half a year or so ago, there were a couple of free DSD downloads available, but I can no longer find them now.

 

And no, you do not have to "endure" music of Frank Zappa, if that is not exactly your cup of tea - there are other good more accesible selections of music in Opus 3 catalogue, ALL with constantly high sound quality.

 

Still ( make sure to select 720p resolution for best SQ possible on YT ):

 

 

More of the same :

 

 

 

Correction: free sample DSD track download is still available, click on any of the CSD samplers and follow the instructions. It is Eric Bibb - Meeting at the Building (5.6 MHz)


Edited by analogsurviver - 3/11/14 at 4:27am
post #2432 of 3264
*sigh*

se
post #2433 of 3264

Care to, uh, expound on what's "hidden" in the presentation in terms of the technical details? Or should I not even ask?

post #2434 of 3264
Quote:
Originally Posted by mikeaj View Post
 

Care to, uh, expound on what's "hidden" in the presentation in terms of the technical details? Or should I not even ask?

Of course you are WELCOME to ask.

 

NO. Not in a short reply. 

 

But I will do it - thoroughly. I will post the output of the following :

 

- analog cassette recorder

- analog HIFI video cassette recorder

- CD-R recorder ( redbook, 44.1 kHz/16 bit )

- PCM from 44.1/16bit to 192/24bit - various equipment

- DSD64 and DSD128 ( with various output filtering )

 

- and COMPARISONS among the above - when presented with a 1 kHz square wave at the input and output as seen on an analog oscilloscope display. Real world machines, not sugarcoated manufacturer's version.

 

Please allow a couple of days to prepare and take pics of everything mentioned - it should give everyone a pretty clear idea why I find redbook inadequate. 

 

I have to ask to get a permission to post (a portion of )  recent DSD128 recording to illustrate the whole point - but will make it available to those in posession of native DSD playback only - via PMs.

 

Enough/too much is lost if converted to PCM - even if it is 192/24. 

post #2435 of 3264
Quote:
Originally Posted by analogsurviver View Post
 

That video cracked me up - like VERY few things can. The exact immediate association, if posted, would get me banned in an instant - but suffice to say is that it is very cunningly hiding ( or completely non-understanding  ? ) what it really is all about. Nothing wrong with the presentation etc - but it IS too superficial and misleading to those who are not familiar enough with measurements and/or audibility of certain parameters on QUALITY audio equipment using QUALITY recordings.

OK, I'll bite. What is it hiding/not understanding, and the audibility of which parameters exactly?

 

EDIT: I posted this before seeing your latest reply. I am curious to see what exactly it is you claim is inadequate about PCM.


Edited by cjl - 3/11/14 at 9:08am
post #2436 of 3264
Quote:
Originally Posted by cjl View Post
 

OK, I'll bite. What is it hiding/not understanding, and the audibility of which parameters exactly?

 

EDIT: I posted this before seeing your latest reply. I am curious to see what exactly it is you claim is inadequate about PCM.

Please read the Opus 3 reasoning behind the decision to use DSD - CAREFULLY SO. It is in there - I have not reinvented the wheel, rediscovered America  - or anything of the sort. Merely applying what I have been using in analog equipment for the past 30 or so years - with digital finally (sort of - via DSD) catching up.

post #2437 of 3264
Quote:

Originally Posted by analogsurviver View Post
 

- and COMPARISONS among the above - when presented with a 1 kHz square wave at the input and output as seen on an analog oscilloscope display. Real world machines, not sugarcoated manufacturer's version.

 

Please allow a couple of days to prepare and take pics of everything mentioned - it should give everyone a pretty clear idea why I find redbook inadequate.

 

That is, as long as you prefer to "listen" to your music only by looking at it on an oscilloscope. In reality, it is possible for two audio signals to look very different and sound the same (for example, due to phase errors that are the same on both channels, and do not result in significant variation in group delay), or to look almost identical and sound clearly different (e.g. 8-bit quantization or crossover distortion may not look obvious on a low resolution picture of an oscilloscope, let alone with a square wave).

 

Why not try some ABX testing instead between 192/24 format PCM audio, and a version of it that has been converted to 44.1/16 and then back to the original format ? Preferably post the samples as well, so that it can be verified that the conversions were done properly.


Edited by stv014 - 3/11/14 at 9:28am
post #2438 of 3264

Are you referring to this page: http://www.opus3records.com/dsd.html ?

 

If so, the only real testable claim made is that DSD is superior to PCM in terms of its phase linearity. Aside from that, it's just a bunch of handwaving. As for the phase linearity? PCM doesn't inherently do anything to the phase, if implemented correctly. The antialiasing filter used prior to the sampling however can significantly affect the phase, especially at high frequencies. This is largely solved by oversampling though, which allows for the use of a very simple, well-behaved analog filter with a much shallower slope, followed by a much steeper digital filter once the signal has been digitized at the higher frequency (before subsequent downsampling).

post #2439 of 3264
Quote:
Originally Posted by stv014 View Post
 

 

That is, as long as you prefer to "listen" to your music only by looking at it on an oscilloscope. In reality, it is possible for two audio signals to look very different and sound the same (for example, due to phase errors that are the same on both channels, and do not result in significant variation in group delay), or to look almost identical and sound clearly different (e.g. 8-bit quantization or crossover distortion may not look obvious on a low resolution picture of an oscilloscope, let alone with a square wave).

At the same time, looking at signals on an oscilloscope can be very interesting, if you understand what to look for. As I said before, I'll be curious to see the results (though as you said, it isn't a really good tool to see if the signals are audibly different - a spectrum analyzer would be much better at that task).

post #2440 of 3264
Quote:
Originally Posted by cjl View Post
 

At the same time, looking at signals on an oscilloscope can be very interesting, if you understand what to look for. As I said before, I'll be curious to see the results (though as you said, it isn't a really good tool to see if the signals are audibly different - a spectrum analyzer would be much better at that task).

I agree regarding oscilloscope vs spectrum analyzer - I would love to have one around.  Maybe in not too distant future ...

 

But it can be seen on the scope too, if you know what to look for. As PCM uses brick filter, it is almost "digital" difference - signal is either present or absent, making exact quantzation/quality almost academic. As stated above, I would not mind a spectrum anylyzer in my inventory.

post #2441 of 3264

and the dsd version was made from?

isn't it like saying that a flac version made from my mp3 track is audibly better than the mp3. I doubt that good old frank zappa did the recordings in dsd at the time. so from my point of view all audible differences could only come from remastering, or distortions related to the file format being decoded to analog.

it looks like what you intend to demonstrate is that 2 different masterings are different, instead of showing that 2supports are different. or maybe I didn't get your explanation?

post #2442 of 3264
Quote:
Originally Posted by cjl View Post
 

Are you referring to this page: http://www.opus3records.com/dsd.html ?

 

If so, the only real testable claim made is that DSD is superior to PCM in terms of its phase linearity. Aside from that, it's just a bunch of handwaving. As for the phase linearity? PCM doesn't inherently do anything to the phase, if implemented correctly. The antialiasing filter used prior to the sampling however can significantly affect the phase, especially at high frequencies. This is largely solved by oversampling though, which allows for the use of a very simple, well-behaved analog filter with a much shallower slope, followed by a much steeper digital filter once the signal has been digitized at the higher frequency (before subsequent downsampling).

Yes.

 

True.

 

There is one crucial fly in this ointment - above Nyquist frequency, everything is chopped off in PCM. It is this all-important transient that all is about which is being lost using PCM - AND IT CAN NOT BE RETRIEVED at a later stage. It is possible to fiddle with PCM any number of times and loose nothing AFTER the initial recording - but crucial information  is already lost in the very first PCM. 


Edited by analogsurviver - 3/11/14 at 10:03am
post #2443 of 3264
Quote:
Originally Posted by analogsurviver View Post
 

Yes.

 

True.

 

There is one crucial fly in this ointment - above Nyquist frequency, everything is chopped off in PCM. It is this all-important transient that all is about which is being lost using PCM - AND IT CAN NOT BE RETRIEVED at a later stage. It is possible to fiddle with PCM any number of times and loose nothing AFTER the initial recording - but crucial information  is already lost in the very first PCM. 

True, but all the information above Nyquist is inaudible, since it's above 22kHz (or, in the case of higher-frequency PCM, above 44, 48, or even 96 kHz).


Edited by cjl - 3/11/14 at 10:45am
post #2444 of 3264

What do you want to show with the square wave? Phase shifts? Removal of frequencies above Nyquist? Again, you need to demonstrate that these sound different, not that they look different on the scope. Yes, without infinite sample rate, you're chopping off information, but how much of it is (a) audible and (b) actual musical content you're interested in? Depends on the input and the sampling rate.

 

Probably the best way to test this is to run something through A/D and D/A (with the dreaded PCM) and see if that sounds different than the original. Current evidence doesn't seem to indicate that people can detect the A/D -> D/A thrown in there, so... maybe you can try and prove otherwise.

post #2445 of 3264
Quote:
Originally Posted by cjl View Post

the only real testable claim made is that DSD is superior to PCM in terms of its phase linearity.

Even that is dubious. Phase shift per se is inaudible in typical amounts. It's a total non-issue, a bogeyman invented by audiophile magazine writers to explain stuff they don't understand.

--Ethan
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Sound Science
Head-Fi.org › Forums › Equipment Forums › Sound Science › Testing audiophile claims and myths