Sound Quality Vs. Measurements - Page 687 - diyAudio
Go Back   Home > Forums > Member Areas > The Lounge

The Lounge A place to talk about almost anything but politics and religion.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 24th July 2012, 10:22 AM   #6861
fas42 is online now fas42  Australia
diyAudio Member
 
fas42's Avatar
 
Join Date: Jun 2012
Location: NSW, Australia
Blog Entries: 11
Quote:
Originally Posted by dvv View Post
Did you by chance keep records of the time required to bump the standard 16-bit WAVE format to higher levels? Just curious ...
Just to remind myself, I tried it again. I took a track from the 80's, what many people would regard as pop fluff, Dexy's Midnight Runners - Come on Eileen, which started as a 128kbps MP3, size of just under 4 Mbytes, 4 1/4 mins running time. Imported into Audacity, resampled to 384000 rate, exported as 24 bit WAV file. Resampling on Dell laptop took 1/2 hr with CPU at 90% usage, exporting took another 1/4 hr, final file size 571 Mbytes!!

But this silk purse project works, for me. Once the DAC had warmed up a bit, the difference between original and resampled was chalk and cheese. The MP3 is a scratchy, unpleasant mess, the hi res conversion had good tonality of the instruments, nice space rendition, depth, imaging, all the usual adjectives.

Sometimes, miracles are possible ... . Just wondering, whether anyone else has tried this bizarre exercise ...?

Frank
  Reply With Quote
Old 24th July 2012, 10:27 AM   #6862
diyAudio Member
 
Join Date: Mar 2007
Location: Oxfordshire
My view of this is that digital is another level of complexity which we too happily live with .

We can live on tinned food until eternity and probably be healthy if the food is correctly conceived . It is not the same as real food . I am not a vegetarian although I love vegetables . Meat is seldom much more than dead when I eat it . Other food to me is " digital " food .

We had a campaign for real ale in England . Beer as it was made for centuries especially if without hops . Some critics call it warm/ flat beer . Yes that is partially true 50 F ( 10 C ) is about the right serving temperature ( lower than red wines , higher than whites ) . Low grade beers do not taste good at 10 C . Now it is virtually impossible to buy beer which is not of this sort . The problems of going bad are never seen ( it was said rubbish beer kept better ) , more often the barrel runs out . This beer is alive to a certain extent and needs skillful management . It is also cheap considering the care taken .

Somehow digital has taken away some pride we once had .

Notice I didn't mention organic foods . I think they are better because the
producers care more because they are organic . Would be happy to be told analogue people care more .
  Reply With Quote
Old 24th July 2012, 10:42 AM   #6863
gk7 is offline gk7
diyAudio Member
 
Join Date: Oct 2007
Location: Vienna, Austria
Quote:
Originally Posted by fas42 View Post
Sometimes, miracles are possible ... .
No.

Quote:
Originally Posted by fas42 View Post
Just wondering, whether anyone else has tried this bizarre exercise ...?

Frank
Its bizarre, indeed. Reading a 571 Mb file for playback would actually _increase_
the total system load (not that the system load would have an impact on sound quality like some believe).

The losses in MP3 occur during the _encoding_ stage, there is _no_ way to regain information which was discarded in the first place.
  Reply With Quote
Old 24th July 2012, 10:51 AM   #6864
diyAudio Member
 
Join Date: Mar 2007
Location: Oxfordshire
I remember years ago that it was said the errors of digital are predictable which means restoration is is possible . Micheal Gerzon pointed out that not all errors are . Some of the errors off early digital might be analogue . If so keeping some note of circuits will be important .

It was said years ago that if certain functions in digital circuits were done by circuits known to be poor in analogue then similar sonic traits were noted . I don't know as I never tried . The critics saying that it was harder to prove if digital . His statement was if it works well in analogue it should be used where practical in digital . I suspect it is hype . However a sensible bit of caution .

Tamla Motown digitally mastered their collection and got rid of the master tapes I think I read ? That was in the days of early digital ( Sony PCMF 1 ) . Hope you are right Frank . Digitally remastered . I understand it , however feel they over play it . Digitally offer if more truthfully . Fact that a vinyl master would sound wrong has nothing to do with it . It is implied that the vinyl master was inferior . No , like colour photography there was/is some processing .
  Reply With Quote
Old 24th July 2012, 10:55 AM   #6865
SY is offline SY  United States
diyAudio Moderator
 
SY's Avatar
 
Join Date: Oct 2002
Location: Chicagoland
Blog Entries: 1
Quote:
Originally Posted by gk7 View Post
The losses in MP3 occur during the _encoding_ stage, there is _no_ way to regain information which was discarded in the first place.
Second Law is optional in hobby audio.
__________________
You might be screaming "No, no, no" and all they hear is "Who wants cake?" Let me tell you something: They all do. They all want cake.- Wilford Brimley
  Reply With Quote
Old 24th July 2012, 10:55 AM   #6866
diyAudio Member
 
abraxalito's Avatar
 
Join Date: Sep 2007
Location: Hangzhou - Marco Polo's 'most beautiful city'. 700yrs is a long time though...
Blog Entries: 101
Send a message via MSN to abraxalito Send a message via Yahoo to abraxalito Send a message via Skype™ to abraxalito
Quote:
Originally Posted by dvv View Post
In engineering especially, the overall optimum may, and in reality very often does, mean that for the sake of achieving the optimum point for the whole, subsystems may have to be purposely moved away from what may be their own subsystem optimum.
No, I disagree - your example was an example of brand politics/marketing rather than engineering optimisation.

You cited that the compromise was made for 'sales optimum' - that's just a number. A number is without value - hence this was done because bean counters had to be placated. Separating the engineering design from the marketing would lead to the same result - compromise, and probably this split personality effect is present in abundance in GM's culture.
__________________
No matter if we meanwhile surrender every value for which we stand, we must strive to cajole the majority into imagining itself on our side - Everett Dean Martin
  Reply With Quote
Old 24th July 2012, 10:55 AM   #6867
tsiros is offline tsiros  Greece
diyAudio Member
 
tsiros's Avatar
 
Join Date: Jun 2012
Location: Patra, Greece
Send a message via MSN to tsiros Send a message via Skype™ to tsiros
1) the mp3 player has a worse mp3 decoder than audacity (mp3 encoding is a standard. mp3 decoding is not)

2) the dac performs better when fed 384 KHz 24 bps signal

those are two reasons i think would make them sound different.

but without an ABX test we can not be sure there even exists a differece
  Reply With Quote
Old 24th July 2012, 10:57 AM   #6868
fas42 is online now fas42  Australia
diyAudio Member
 
fas42's Avatar
 
Join Date: Jun 2012
Location: NSW, Australia
Blog Entries: 11
Quote:
Originally Posted by gk7 View Post
The losses in MP3 occur during the _encoding_ stage, there is _no_ way to regain information which was discarded in the first place.
Information is NOT being gained through resampling, rather the replay process makes a mess of unraveling the detail, which has not been lost, when it tries to both decode the compression and have the DAC do the oversampling necessary to internally handle the lower sample rate of conventional WAV.


That's at least how I interpret these results, which I'm sure will vary from m/c to m/c. The better the quality of the soundcard, probably the less the discrepancy.

I've done this "trick" also on jazz tracks, and classical, and the audible benefits are heard every time.

Frank
  Reply With Quote
Old 24th July 2012, 11:08 AM   #6869
diyAudio Member
 
Join Date: Mar 2007
Location: Oxfordshire
A bit of history .

http://www.aes.org/aeshc/pdf/fine_dawn-of-digital.pdf
I note the first commercial digital was Decca . 18 bit 48kHz it is said . It was a paper thin recording which might have been the acoustics ? BBC 13 bit was/is excellent and enjoyed by many for years before CD . As Julian Vereker I think said , why didn't Philips choose that ?

There is I suspect an error in the text . The wartime scrambling was by using identical noise discs for encoding and decoding ( I think a Vocoder as used by musicians ) . These discs were periodically replaced . It seems that the U boats could simply listen to trans Atlantic cables .
  Reply With Quote
Old 24th July 2012, 11:58 AM   #6870
DF96 is offline DF96  England
diyAudio Member
 
Join Date: May 2007
Quote:
Originally Posted by fas42
Information is NOT being gained through resampling, rather the replay process makes a mess of unraveling the detail, which has not been lost, when it tries to both decode the compression and have the DAC do the oversampling necessary to internally handle the lower sample rate of conventional WAV.
As others have said, MP3 throws away information. That information is lost. The remaining information is then encoded. A good MP3 decoder may produce more of the unlost information than a poor decoder but it can't recover the lost information. The best that can be done is to guess what the lost information might be from what has not been lost, but this is basically replacing music with musically-sounding-artifacts. It might even sound better, but it is not recovering lost detail.

Perhaps 'replacing music with musically-sounding-artifacts' is a description of how MP3 works! You certainly don't get an output signal which looks/measures anything like the input signal.
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Quality Control differences = variations in sound quality? KT Class D 3 4th June 2014 12:02 AM
Sound Card for Measurements Marik Solid State 2 2nd January 2012 08:59 PM
Sound Card Recommendations (For Audio Measurements) dchisholm Equipment & Tools 5 16th July 2011 09:40 AM
How to protect sound card during amp measurements? okapi Everything Else 13 2nd September 2008 03:06 PM
Sound cards - test and measurements jackinnj Everything Else 2 5th July 2003 03:02 PM


New To Site? Need Help?

All times are GMT. The time now is 12:55 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2