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DolbyA decoding feedback -- 'feral' examples (yes/no)


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1 hour ago, John Dyson said:

I added some equivalent 'olvia newton john' snippets.  the undecoded compression is pretty obvious there also.

 

https://www.dropbox.com/sh/d2dyuonx8fk3pwv/AAArjQgYoo_Skpy8YSiOuxpha?dl=0

 

 

I listened to the files and here's what I found:

 

Karen Carpenter

#1, #2 and #4 -- I thought I heard a difference but too close for me to call it.

#13  There was one point after she paused singing where some instruments kicked in -- the unprocessed file had less definition of those instruments than the processed file.

 

Olivia Newton John

#4  - I don't think I heard a difference.

#14 and #19 - the processed file gets rid of the some fuzz

#23 -- the processed file has less "digital glare"

 

Does this make any sense?

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14 minutes ago, sandyk said:

HI Lucretius 

 Just for one example .

 I find that the decoded version of "ONJ-Take Me Home Country Roads" has the chorus sounding much cleaner (less harsh sounding) and clearly defined. When her voice kicks in it is a little softer and purer sounding , with noticeably improved separation between elements for the rest of the track. This version sees me wanting to hear the whole track.

(Admittedly though, I have had quite a bit of practice listening to John's various examples)

 Regards

Alex

 

I heard those differences initially but I thought that the two tracks were not level matched - the processed track appeared more quiet. When I turned up the volume on the processed track vis-a-vis the unprocessed track, the two sounded very similar to me.

 

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3 hours ago, John Dyson said:

The hobby was somewhat related to AT&T Bell Labs (where I worked) to also work on/develop the FreeBSD OS kernel.  I have had LOTS of fun -- and lets not even get into my 'Forrest Gump' emuation history - with my crazy 1 degree of separation.  I never got the major accomplishment of people in my midst (or nearby.)

 

Did you know Ken Thompson, Dennis Ritchie and/or Brian Kernighan?

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  • 2 weeks later...
46 minutes ago, John Dyson said:

 

I just looked up the 'Dynamic Range' tape on loudness-war, and compared with my Polar CD (which is close-to-original) that I do have, and a DR of approx 14dB is par-for-the-course of an EXCELLENT CD.   Of course, that doesn't actually measure the full quality (all kinds of things like proper decoding, etc.)  I am willing to listen to a 30second snippet to determine the character of your CD.  But even IF it is DolbyA encoded, as a recent private correspondent mentioned -- he likes the brighter, slightly compressed high end kind of sound.

 

  I do have a copy of the Readers Digest, 4CD release, but the 2004 version of Readers Digest. IT IS SAD -- very compressed...  THAT DOESN"T SAY THAT YOURS IS BAD.  Mine is much more recent, typical of loudness wars damage, and relegated to both the storage bin and my archives disk -- not my day-to-day usage disk.

John

 

 

 

As for the "slightly compressed" comment,  for reference here are my DR measurements:

 

SONG                                CD*                       Processed

Waterloo                           12                               12

S.O.S.                                 12                               12

Mamma Mia                     14                               13

 

*20th Century Masters: The Millennium Collection: The Best of ABBA (released in 2000)

https://www.discogs.com/ABBA-The-Best-Of-ABBA/release/5421066

 

 

Thanks!

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21 minutes ago, John Dyson said:

The DHNRDS shouldn't much affect the 'Dynamic Range' that measures the higher level dynamics.  The DHNRDS DA decoder only has substantal effect below -20dB on the MF band, and about -10dB on the higher freq bands .  On pop material, the MF band is usually pinned at 0dB loss, and it is only the LF band (up to 74Hz/Q=1.070) and the range between 3k and 20+kHz that have any change in dynamics.  The MF band (80-3kHz) only starts pushing down the gain at very low levels (like at the quiet beginning of certain ABBA songs.)

 

Most of the signal is in the 80-3kHz band, so the 'general' dynamics are little affected even though the noise and HF dynamics are very seriously effected.  (If you watched the gain display on the DHNRDS, within very short periods the gain on the 9-20kHz band can change 15dB in a very very short interval -- much faster than the short interval in quiet spaces between syllables.)   The 3-9k range is a bit more tame.


One note, all of the fancy antiMD and anti-IMD calculations (other than some very primitive stuff) isn't done to the MF band, because it really doesn't change much and doesn't produce the 'fog'!!!


So, the difference in the decoded signal isn't so much on the peaks, but in the 'meat' of the sound.   When I measure with the SOX 'crest factor' and 'peak-RMS' ratios, usually there is a slight difference.  In the case of the SOX measurement there is usually between 0dB and maybe 1dB increase in the peak-RMS and the crest factor is also slightly modified.  Interestingly, the true DolbyA HW will increase the crest factor higher, but that higher measurment is caused by errant peaks that would be nice to clip.  The DHRNDS doesn't produce as many of those peaks in the middle of nowhere...

 

So -- the results that you get are perfectly normal!!!   But it is good to manage expectations on those measurements.

 

John

 

 

The graph below is for 'Waterloo'.  The blue is for my CD. The white is the processed version.

 

 

image.thumb.jpeg.14fd8982e327e8e0ab01abfd4f6f00db.jpeg

 

 

The largest frequency drop-off (for the processed file) appears between 7 and 20kHz.  Is this to be expected?

 

 

 

 

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6 hours ago, Mayfair said:

 

I've been following your posts with interest and was wondering if all ABBA tracks have the Dolby-A decode problem,

 

 I have a 4 CD compilation released by Reader's Digest in Canada in 1992 called "The ABBA Collection".  Subjectively it sounds to me like someone really cared how it sounds. 

https://www.discogs.com/ABBA-The-ABBA-Collection/release/2184279

There's a discussion about the 1992 compilation on the Hoffman forum 
https://forums.stevehoffman.tv/threads/abba-the-best-sounding-albums-on-vinyl.435549/page-18

 

After reading the discussion on Hoffman and listening, I was wondering if the tracks on this particular compilation may indeed have been sourced from the original masters.  

 

I don't know if this helps without samples of the actual track, but JRiver Media Center's audio analysis gives the following results for the 1992 Reader's Digest Collection version of "Super Trouper"
Volume Level (R128) -6.9 LU
Volume Level (ReplayGain) -1.86 dB
Peak Level (R128) +0.2 dBTP; -0.1 Left; +0.2 Right
Peak Level (Sample) -0.1dB; -0.1 Left; -0.1 Right
Dynamic Range (R128) 4.4 LU
Dynamic Range 14 dB

 

See http://dr.loudness-war.info/album/list?artist=ABBA&album=The+ABBA+Collection

 

Seems normal except Waterloo (the song) and S.O.S. seem slightly compressed.

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39 minutes ago, Mayfair said:

Oh, yes  - "Money for Nothing" -  18 dB DR in 1985;  7 dB DR in 2005 20th Anniversary Edition.  Seems to me akin to remastering the Sistine Chapel in DayGlo.  Relative perfection appears to be matter of willingness, not ability.  New releases in classical music and to a much lesser extent jazz  (where creeping loudness has crept in) show off what recording technology can achieve when both the willingness and ability are there to use it. IMHO.

 

The 2013 MFSL SACD isn't too bad:

http://dr.loudness-war.info/album/view/127394

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