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

[John Dyson]

I took a bit of advice -- trying to see if people might agree about the possibility (I say probablility -- give opinons).

Sometimes the decoding can sound okay, likewise sometimes undecoded (with EQ) can sound okay.

 

Things to look for:  HF compression improvement, Stereo depth/ambiance (fullness)

Problems with DolbyA decoding:  choosing the correct calibration and corrective EQ.  I tried to do my best on the examples.

Problems with decoding unencoded material:  serious surging.  really/dead highend (sometimes), but crazy/extreme sibilance.

Problem with undecoded:  sometimes hiss, sometimes a little strident high end, HF compression

 

I am using slightly long snippets (still under 1 minute), if I get complaints -- I can shorten them or segment them if needed.

They are mp3, but the Dropbox player sometimes gives 'phasing' sounds -- I make them mp3 for quick online evaluation, flac available if desired.

 

First example, Bread -- Audio Fidelity AFZ5 197

This album is in question.  This is a *difficult* choice!!!  I don't even know for sure.

I have also included the 'before' decoding.

 

https://www.dropbox.com/sh/fopp4ll0ua6hrue/AABm-3EVloApEihtnBV29rf9a?dl=0

[John Dyson]

Got another example -- Nat King Cole...

Audio Productions Remaster -- 2011

Issues same as before -- esp listen for hiss here.

 

Listen for the compression on the choral vocal on 'Orange Colored Sky' -- compressed, but when decoded -- more 'natural' and louder.

 

https://www.dropbox.com/sh/vm7iuupm3n4vee4/AABGvkN7DZLxGkq2QAdY_rB1a?dl=0

 

[John Dyson]

2 hours ago, tmtomh said:

Thanks! Are you saying these Audio Fidelity and Analogue Productions masterings sound like they used undecoded Dolby A tapes as their sources? That can't be the case with the Nat King Cole, can it? Apologies if I'm misunderstanding.

For the Nat King Cole -- look at the hiss for example.  It is too great for those examples -- the tape wasn't that bad back then.  Also, look at the increased hiss vs. frequency above 10kHz on a spectogram -- that is typical of DolbyA encoding.

So yes, the 'original' versions are likely (not 100%) DolbyA encoded.

I'll answer another comment below -- but I might have gotten the compensating EQ a little off --  that is one of the problems with Feral DolbyA.

 

* 1/2" 3trk had lots of tape moving under the heads.  Not like 16-32track later on.

 

John

[John Dyson]

1 hour ago, fas42 said:

Okay, I just tried the Bread, Baby I'm a Want You ... sorry, I prefer the originals, the before - the character of the track is part of the artistry of what was created, and John's processing has dulled the "specialness" of the Bread 'sound' - unlike many, I enjoy the sparkle and lift of well reproduced treble; and therefore don't feel a need to make it go away ... .

I remember playing the orignal Bread vinyl many years ago -- I remember a lush kind of sound, not a bright one.

 

For stereo image -- listen carefully -- I am a little surprised that the discontinuous sense of forward (L+R)  and back (LR+RR) in the stereo image on the original isn't obvious.  If you listen to the ambiance on the decoded copy -- especially near the beginning - hear that the sound between the forward and parallel (I mean L+R and the sensation of LR + RR) is continuous.   That flat or odd stereo image on the original, where there is a LF + RF and only a parallel stereo image -- nothing in between.

 

Likewise, the noise veil on Bread on the original is two strong -- listening to the sound, it wasn't a heavy mixdown (like Nat King Cole was on a full 3trk, not multi-track) so the hiss should not be that great.)

 

But, you are welcome to disagree -- I am still not 100% sure, but there are too many defects in the original for my taste.   It is VERY possible that I got the compensating EQ wrong also -- they usually seem to use -3dB at 3k for pop, and it might have needed a bit more (like a +6 instead of +3 compensation.

 

John

[John Dyson]

14 minutes ago, sandyk said:

 

 But , you are using just a laptop to listen to these, are you not ?

 

To carefully compare, one would need headphones on this material -- headphones that someone is really used to listening on.  Or, an extremely image-stable listening room with good (I mean damned good) speakers.  This is NOT an easy thing to do, and I am providing the *most difficult* possible examples to compare.  Maybe it is self-destructive, but I believe that showing the most 'on the edge' examples might illustrate my plight, and the fact is that there are 100's of additional examples that are infinitely more obvious that DolbyA has leaked.

 

I am producing a different run of the Bread examples, but with a different EQ.  It does sound more bright, it takes about 5 minutes to do a run of snippets.

 

John

 

[John Dyson]

New decode attempts -- the brightness is closer to the original, but now the stereo image is where I expect it to be (more continuous, rather than discrete forward and side (or rear -- depending on listening environment)) but the undecoded version has a stark stereo image.

 

The hard thing with this stuff -- getting the right mix between the calibration and the EQ -- because they almost always (not every time though) apply at least a -3dB at 3k EQ -- fools people into thinking that it is okay.  However, stereo image (and sometimes noise spectrum) is the clincher.

Look for the '-V2.mp3' files for the new decodes with new configuration.  It might be more tolerable -- not sure.

https://www.dropbox.com/sh/fopp4ll0ua6hrue/AABm-3EVloApEihtnBV29rf9a?dl=0

 

John

[John Dyson]

3 hours ago, tmtomh said:

Thanks! Are you saying these Audio Fidelity and Analogue Productions masterings sound like they used undecoded Dolby A tapes as their sources? That can't be the case with the Nat King Cole, can it? Apologies if I'm misunderstanding.

Yes -- there are enough 'tells' in the sound that the probability of not being decoded is high.  I have other cases where there is NO CONTEST.

 

Okay -- the Bread example has better brightness.  The stereo image should seem improved. (uploaded a V2 version.)

I think that the Nat King Cole with the better noise characteristics is set where it should be.

 

John

[John Dyson]

Okay -- no more tries on Bread -- till we get more discussion...   I have tried one more V3 version.

Normally, the sequence for correction is +3dB@3kHz, +6dB@3kHz and last, +5dB at 3kHz.  This is BEFORE decoding.

Sometimes, like on ABBA they used a Q of 1.0 instead of 0.707 (yes, it is critical.)

It almost never helps to do an EQ of 9kHz before decoding, and I think that when I need to do that -- I have made a calibration error.

On all examples, I did NO post decoding EQ -- this is RAW RAW RAW results.

If one was to do any post decoding EQ, it might be -1dB@9kHz/Q=0.707 -- to compensate for the (lack of) vinyl cutting behavior.

 

There is the default, a V2 and a V3 decode.  After listening again -- I think that the V2 decode is a bit better.   The V3 seems to have an uneven 'crispness', but V2 seems to be more intense, but more even crispness.

As my recording engineers friends say -- you NEVER know what the masteringing has done.

 

https://www.dropbox.com/sh/fopp4ll0ua6hrue/AABm-3EVloApEihtnBV29rf9a?dl=0

 

[John Dyson]

Okay -- I lied about not working on Bread -- I created a -V4.mp3 version.

This is really difficult because the mastering person had messed around with the recording (EQ to hide the DolbyA, probably other EQ that I don't know about, I don't know the calibration, so need to guess by listening.)

 

My project partner warned me about the rather large variation in DolbyA unit behavior -- and I heard something in the V2 decode (the other good one) that allowed me to make an adjustment (they were using a DolbyA unit with a calibration offset of about 0.75dB for the 9kHz band.)   I created a new -V4.mp3 version that REALLY sounds better.  The vocals are more clean sounding.

 

This is one of the troubles with the DolbyA setup -- esp the DHNRDS with the extreme clarity.  An old DolbyA would have fogged over these differences (the detail would have been lost).    HD Carpenters version is coming some time today.

 

(The purpose of this is NOT to get people to do their own decodes -- IT IS DIFFICULT/TRICKY -- but to get the distributors to do the right thing!!!)

 

https://www.dropbox.com/sh/fopp4ll0ua6hrue/AABm-3EVloApEihtnBV29rf9a?dl=0

John

[John Dyson]

7 hours ago, Doak said:

Finally got around to listening to the Bread snippets - Wow!!!

IMO this is probably the most important thing I have seen on this site as far as increasing sound quality.

Thanks for chasing this, John. 

Now I need to get to your more recent posts .

 

Thank you, and guess what -- I just found a pair of quality improvements the decoder (the DHNRDS DA), so the results are being re-run probably tomorrow night.    I am in the midst of the verification testing, and will pass the decoder to Richard tomorrow for his testing.  These are 2nd order issues -- but the fixes/improvements do help the sound, and make the decoder much easier to use.  There haven't been any changes for about 1.5months -- that is REALLY a long stability period for anything that I work on (tweak tweak tweak.)

 

At that point, I will be freed up to do some (IMO) much improved decoding -- it embarasses me about the actual improvement coming up -- I wish that I would have caught the issues before.    The sibilance is much better, and the ambiance should be more smooth yet (nothing about attack/release or anything like that -- but it is a phasing thing intended to cancel distortion, but it caused more problems than helped.)

Thanks again -- The DHNRDS DA decoder itself and the fact that DolbyA is leaking are BOTH important to me.  The DHNRDS notwithstanding ,I think that the DolbyA being leaked should be important to ALL of us.   I know that everyone understands this:  I can make mistakes on any one example, but doing 'mastering' isn't really the purpose of this discussion.  Even though the demos might be entertaining -- and I am willing to decode 'favorite songs' for people offline, my purpose here is to wake music listeners/lovers up to the *possibiity* of feral DolbyA.

 

As mentioned before, for decoding ones own collection, I am happy to make copies of the DHNRDS DA with a timeout of maybe 2 months to play with.  I am not into selling the software -- not my thing, and if there wasn't a professional side of the project, I'd probably just give the decoder away.  Also, the DHNRDS is NOT fun to use (tedious, irritating, ibuprofen&tylenol are necessary medications when using it.)

 

The promised Carpenters comparison will appear when the updated demos/comparisons (more convincing) are uploaded tomorrow.

I do accept and take criticism VERY seriously, but also happy when the program/results are criticized -- it actually HELPS me.   I adore posiitive feedback, but I appreciate/respect constructive criticism.

 

I want people who participate to ENJOY this exercise.  It is like 'detective' work :-).

 

John

[John Dyson]

5 hours ago, fas42 said:

Right, just has a listen to V5, of Baby I'm-a Want You ... sorry, doesn't work, at least for my laptop playback - I find I get a build up of a sense of distortion in the sound; there's a loss of sweetness, compared to the before - if I was listening to the full song I would probably stop play before the end, because I'm getting irritated.

 

You are right about there being a problem with the decoder in this case.  The problem  popped up once in a while -- the reason for so many decoding attempts.   Per my previous comments -- a new decoder is being verified just this second.  Many people don't seem to be super sensitive to the problem...  Summing up the issue -- there were phase twists through the bands.

(As noted before, I am not selling the decoder here -- but talking about DolbyA material leaking -- but read on.)

 

The problem appears  on sibilance once in a while.  It is good to have been away from the decoder for so long (over 1 month since the code had been touched.)   Some kind of odd phasing aspect of certain recordings - a legacy design choice that I made was wrong.  The bug was in very old, legacy code -- some rotted stuff and a rotted idea.

 

Alex brought the issue up a few weeks ago, but it is SOOO complex that it has taken a few wks of thinking to figure out the problem -- and specifically the decoding experience with Bread.   The problem always used to pop up on Carpenters all of the time also -- a certain kind of vocal sibilance would drive it nuts -- same way with certain kinds of ambiance.  I have needed some 'golden ears' to help wake me up -- neither my project partner nor myself have the kind of hearing needed (my hearing adjusts to the decoder after many many test attempts -- my brain starts fixing the problems.)  This problem that some audiophiles don't admit happens for them was driving me crazy when trying to find audible defects.

 

However, on orchestral/jazz -- it was absolutely perfect -- something odd was going on, and it is now fully understood.

Actually, I was noticing SOMETHING WRONG on creating test material for the C4 project (decoding feral and official master tapes to create the tests.)

 

As I noted before, there will be new decodes for everything tonight -- the new tests are astoundingly (and embarrassingly) better (still, in most cases, was previously better than DolbyA on the previous version that you didnt' like.)  I wasn't doing any post-processing, and a slight phase shift/EQ on the 9k band cleaned up most of the mess.  (It had to be a phase shift also -- but the problem is -- that shouldn't have helped -- there was a phasing problem -- and that is EXACTLY what I found.)

 

Also, just because you heard some distortion (truly, it wasn't *distortion* in a conventional sense), that doesn't mean that the material wasn't DolbyA encoded -- feral DolbyA is EXACTLY what I am discussing here.  The DHNRDS DA decoder bug (nothing to do with attack/release or anything like that) isn't the so much the issue.  It is fortunate that I found the bug though.*  The bug was actually an attempt of a low level form of distortion cancellation -- part of which was inverting every other band -- but apparently caused more problems than distortion cancellation, which isn't needed with the current design (it was a legacy concept.)

 

* I found the bug, but it required people like Alex and others along with other factors to motivate the fix.

 

The bug had nothing to do with the anti-IMD that I talk about all of the time, and the bug sometimes caused problems even in the lowest decoding modes.  I am beating myself to death doing verification testing JUST THIS SECOND.

 

The DHNRDS is 21000 lines (about 9000 lines of it is raw, highly optimized SIMD DSP code).   It is crazy complex -- and the smallest mistakes (these mistakes just fixed about 10 lines total -- coefficients and remove some cancellation) can make it work less than 100% correctly.  It is a lot of very detailed/precise code, and even though I had been dealing with aspects of the problem for 6 months, I have to rightfully admit that Alex and these recent decode attempts (for the C4 project and these demos) have been motivation to figure out/fix the problems.

 

John

[John Dyson]

The problem with 'Bread' worried me so much that I just ran another decoding pass ahead of schedule  -- with new DHNRDS V0.9.7C  version in testing.  I think that the problems will be mostly resolved.  The phase twists are gone, so that makes the sibilance more stable.   (Again, the phase twists were a result of very old, legacy code -- like over 1yr old.)  I am glad that they have been fixed, because this has been vexing me for the last few months.  I am NOT claiming perfection -- but with these results, they seem much closer to what I had been hearing on other material.

 

The '01 Make it with you' seems to have some odd dynamics.  I don't think that it is wrong, just a bit confusing.

 

Also included .flac files for the snippets.  Playing .mp3 through Dropbox can be misleading, so since a person might do a download for more precise listening, might as well get the best possible quality, right?  On this material, there is actually a very noticeable mprovement of .flac over .mp3.   Normally, .flac and .mp3 sound almost indistinguishable to me (other than the lack of timing resolution) -- this does sound different.  I used lame '--preset insane -q 0' for the .mp3 encoding.

 

If you feel that you need entire pieces to evaluate, contact me directly and we can make arrangements.

Carpenters and the rest of the previous decode updates will be coming tonight.  I did this early because of people being misled by my mistake/bug.

 

Noting again -- this is not intended to be a demo about the DHNRDS DA decoder, instead it is attempt to demonstrate leaks of DolbyA material.  However, further constructive criticism about the DA is VERY welcome.

 

Constructive criticism really helps me...  I GREATLY appreciate and respect the criticism so far!!!

 

Thanks SO VERY MUCH!!!

 

https://www.dropbox.com/sh/fopp4ll0ua6hrue/AABm-3EVloApEihtnBV29rf9a?dl=0

[John Dyson]

51 minutes ago, PeterSt said:

Hey John,

 

Of course I like to have a constructive contribution here. But well, if telling it is all over wrong is that, then hopefully it is ... that.

Raining on your parade ... (but it hopefully helps anyway) ...

 

I listened to the Bread's V6 FLAC (only those). I don't know where you took that from, but there is no dynamics to be seen anywhere.

Oh, good for others would be to tell what the "original album" is. There is of course nothing original about that to begin with -  it is this "The Best of" :

 

The balance is all over wrong or strange. It is processed (OK, it is, but it shows).

 

Gives me the creeps, no matter how short the tracks. It is just wrong. Sorry. There's also a balance thing in the dynamics itself like drum hits not being in balance of what you'd expect for them for loudness. But this includes frequency ranges as far as I can tell.

 

At the start of the 2nd track within 10 seconds my wife asked me what I had done because it sounded so cold and harsh.

 

The S'es are too profound.

You mentioned sibilance - I think I heard that profoundly in one of the tracks only (I forgot which). But sibilance in a flangering way (top end).

 

It sounds heavy and inside out (phase stuff).

 

If I heard right it draws a little to the right side (all 4 of them). If you don't recognize that, then it's me.

 

I wouldn't know what't wrong with this original (collection), but I'm sure you are hearing something.

The dealbreaker for you could be my ultra fast system (from head to tail).

 

Maybe there's some help in my recommendation that you should not put up MP3's in the first place. I mean, the fact that you thing this is comparable, speaks. I am not saying it is so much worse, but I can pick them blindly - always. What you (Dolby) do to it should not be influenced by this. But the fact that you do it anyway, makes me things that you don't hear everything yourself (matter of having the experience and references, like you yourself with Dolby, OK ?).

 

Think carefully about this all; you know I carry a warm heart for you.

Peter

 

PS: The main worry should be the LP-like dynamics. You won't get over that IMO.

 

Thanks, and I am NOT disagreeing with you (rather, I am happy with your input, but still processing the information).

 

I was going to suggest access to a few short examples, but at this point, I do know that there is a hiss/HF compression "problem" with the original, but also the decoder isn't making the material sound like it should.   Even if there is still a DolbyA imprint (there MIGHT NOT be) on the material, it might not be possible to decode because of 'mastering'.  I don't think that the DA is making mistakes itself right now -- I think that it is more of a user issue and trying to reverse engineer the 'mastering'.

 

Almost all 'feral' material needs to be corrected before decoding -- imagine if they did some expansion, what can be done?   It seems that most of the time, the mastering is just a bit of EQ -- but even simple EQ is a pain in the b*tt to compensate for.   This is the reason why the DHNRDS DA is NOT being sold to consumers (if I have troubles, what is ANYBODY, even the most expert user going to do with it?)

 

About the decoder fix:

The decoder actually has linear phase band pass filters for the audio signal (except at 74Hz) -- and there was never actually an input/output delay vs freq shift above about 200Hz, but instead the gain control was happening in different phases.   The gain control phasing issue caused some problems with certain kinds of fast transients (like sibilance that bounces all over the place.)

 

Also, the Dropbox player itself (as you mentioned about mp3) phasor-phases all over the place -- so instead of erring on the direction of convenience, I'll only upload flacs as you suggested. (WRT decoder input/output -- it has a horrendous delay -- up to about 20k samples in the slowest mode, but are all synchronized so that the input/output files have the same timing, but the delay vs. frequency is constant above about 200Hz.)

 

*  An earlier version of the decoder would clobber the SQ/QS matix information -- really embarassing -- it taught me to be much more careful about Hilbert transforms.  All of the HIlbert transforms have to be done in a very intricate way, or the results are phase-shift hell.

 

 

It looks like I am going to 'table' or give-up on the Bread example for now -- until I can get more information/data.   It isn't the most important thing in the world, and I'll put up a more complete caveat when I put-up the Carpenters examples.  I have a very long story to mention about the evil in the Carpenters material...  And then, I cry when I hear the horrid processing against the sibilance in her vocals (all but the 1969 and 1970 album.)

 

If I did make an allegation about the Bread material not being properly decoded, but it really is -- then I apologize.  However, there is *something* wrong with it.  I am NOT a golden ears, and it is a specific kind of problem.   Maybe they used the 'Satin' decoder, which isn't really a 'decoder', but rather a 'processor?'  Something like that does kind of EQ the sound and does some kinds of expansion, but leaves the hiss intact and freq resp is way off....   SO -- again, Bread is tabled until I can get some reference material.

 

Thanks again, and I'll be more careful in the future.

 

John

 

[John Dyson]

Good news -- I got the Carpenters example done (This is the Carpenters singles album from HDtracks.)

This should not be controversial (I don't think!?!?) :-).  I even did comparisons with the original albums -- in some ways I prefer the original albums, but the sound of this 'remastered' version has more interesting effects...  Of course, it is very sad that Karen couldn't re-record portions of the songs.

 

The compression in the 'before' examples is extremely obvious -- esp when compared with the decoded copies.

 

All examples are .flac, but I left one decoded .mp3 available (13 Please Mr Postman) for a quick listen to show that the sound quality is reasonably good.  *There is a 'phasing' sound on the mp3s when decoding directly in dropbox.*  The .flac is the ONLY accurate basis of comparison.  I really wish they had a .flac player -- the old service that I used to use DID have a .flac player, but it seems that everyone that I work with uses Dropbox, so that is what I use.

 

You should notice the thin sound, non-full stereo image of the 'before'.   The 'decoded' versions have the 'V0.9.7C' designator, should have more normal stereo image -- a better/smooth back/side to front ambiance.

 

The snippets are 0-40seconds and 55-85seconds of each song shown.

 

After several iterations, I found that the 'decoding on the cheap' was -5dB @3kHz/Q=0.707, which I undid that EQ before decoding.  This use of 3kHz EQ only is a very good thing for DolbyA, and is a reasonable cross-check that the EQ can be correct (just like the calibration of -14.30dB is a very standard level often used on DolbyA tapes.)   (-13.00, -13.40, -13.80, -14.30, -14.70, -15.00 are usual, and I have found -20.00 is sometimes used on safety masters.)  So, all of the cross checks are good.

 

About Karen's Sibilance -- in some cases, that rough sibilance is even on the original 1970s albums (I have DolbyA copies, straight, non-normalized, non-equalized), and there is little that can be done -- they actually used DolbyA in encoding mode to brighten up Karens voice!!!

 

https://www.dropbox.com/sh/hb4shl4xfwv2gs9/AAA1O1HuoAwYEGu6cjIO93ola?dl=0

 

John

[John Dyson]

Quick comment/update about the 'sibilance' in Karen C's singing.  It really should be there.  If you listen to the 'before' (undecoded), it will appear to have less sibilance (which it DOES have less.)   However, the DolbyA decoding process is an EXPANDER.  It takes the suppressed sibiliance and rebuilds it.  This is one reason why the DA can be vulnerable to excessive sibilance even when it is working correctly -- it is a matter of calibration and EQ.  Since the EQ had been modified by the person who had partially mastered the original download material -- I had to guess at the EQ needed to undo the damage.  If my 'correction' is off by even 1/2 dB, it can make a very noticeable difference.  (The goal is that we consumers never need to do our own DolbyA decode to hear the material correctly.)

 

The question if it is really DolbyA or not -- a few of the music selections can show obviously the dynamic range compression in the recording.  If these examples were not DolbyA encoded -- the sound would really surge...  WRT the quality of my mastering -- it sucks.  Also, the DolbyA special effect used on Karen Carpenters vocals also suck.  There are few recordings where her vocals werent' over enhanced.

For fun, listen to a DolbyA copy of Karen singing (that is, DolbyA encoding on top of DolbyA processing -- yuck!!!)

 

John

[John Dyson]

3 minutes ago, fas42 said:

You're working hard there, John - good on you! 👍

 

V6 in FLAC - good, the sense of distortion is no longer there, perfectly acceptable as a capture of the event. But, I still go back to the before, to get a better sense of the creative sparkle and lift - the soaring strings have a sweetness and 'bloom' in the before, which I find dulled in V6, by comparison.

 

Now, remember this is on the inbuilt speakers of a laptop that does the audio better than many; the treble is not as 'illuminating' as on really sharpish headphones, so this could make all the difference for some.

 

So, John, this may be exactly what suits the systems of many - thanks for going to all these efforts!

 

Thanks!

You know that I am doing my best with the dual-effort.   Trying to (hopefully) get the audiophile community to realize that they have been somewhat cheated -- but not necessarily with malace.  I wouldn't have written the decoder unless I had found the 1992 ABBA Gold CD to have sounded 'just wrong', and after another few months of random-walk research -- decided that it was likely DolbyA encoded.

I am NEVER trying to change someones taste -- just trying to expose the problem for audiophiles who might be interested, and maybe help to improve the situation in some cases.

 

SO, I have two goals -- 1) help open up minds about the possibility that they are listening to a certain sound that was not intended by the artist/recording engineer.   2) help try to create one choice out of a set of solutions -- no profit motive.  My major benefit MIGHT be a feeling that I migiht have contributed something to help.

 

About sound being better or worse -- that is a *conflicted* issue for me.  Sometimes I DO prefer the sound of leaving the DolbyA encoding along with a bit of EQ on the recording to make it sound better.  I think that we all can sometimes prefer a brighter kind of sound -- and on some material, DolbyA doesnt' sound all that bad.

 

On the other hand, like the Nat King Cole stuff -- hiss.  DolbyA wasn't designed to have a 'sound' or be an audio processor.  It was intended to remove some hiss from the analog tape recording process.  Releasing his material with excessive hiss should not have happened (in my opinion.)

 

Now,  we live in a world where DolbyA material has been 'mastered' or changed to the point where it cannot easily be used with a DolbyA decoder (compression, weird EQ, other processing, etc.)   We also live in a world where people have adapted to the sound of DolbyA compression.  I am not in a position to magically say that these situations are wrong -- but it would be nice if the 'good, pure' stuff was available to us.

 

Are we in an evil world?  Well, not because of feral DolbyA -- but sometimes leaving the DolbyA footprint on music is a travesty.  Additionally, the DolbyA HW decoding operation does overly soften the sound.

 

I hope to get enough attention for the issue that the distributors start producing better mastered material.   What is in it for me?  maybe 100 units sold at most at about $50 profit each -- not worth the bother.  I want the industry to provide better qualtiy rather than just make claims about 192/24bits and call it perfection (while the recording is poorer quality than the customer deserves.)

 

Thanks again!!!

 

John

 

[John Dyson]

The DolbyA decoding issue is a real problem.  Proper mastering/processing/preparation is the domain of the distributors.  However, they have been very lax in the last approx 35yrs (since the original CDs.)  Even some of the early CDs (e.g. 99 LuftBallons/99RedBalloons) are not decoded -- in fact that also has the CD pre-emphasis.  Many, many of the digital distributions created from material recorded between the 1960s through 1980s is NOT decoded.  Frankly, IMO they generally suck, and is one reason why I quit my 'hifi' listening back in the late 1980s'.  I couldn't stand the terrible sound -- I thought it to be 'impure' to have to apply EQ for material to be listenable.

 

Back in the early 1980s, I had purchased the Sheffield Labs direct-to-disk album (vinyl) with 'Thelma Houston, I got the music in me', and loved it.  I thought -- my new CD will sound better!!! -- NOT!!!.   I suspect that was the last CD that I purchased in the 1980s or so.  That CD sounded TERRIBLE.   Just recently, a nice friend in the forum was nice enough to lend me a digital copy (from the CD) of 'I got the music in me' for testing -- lo and behold, it was DolbyA encoded!!!   THAT is the reason why that CD sucked, but the vinyl was so nice!!??!?!   Lack of proper mastering on digital material WAS what did me in back in the 1980s or so!!!  WOW!!!  By the way, my decoded copy of 'I have the music in me' is BEAUTIFUL.  THIS IS A 100% true story!!!

 

Should the audiophile do their own decoding?  I don't know -- it is probably not best for most people...   It isn't terribly difficult to 'decode' material, but the problem is: "How do I undo the damage done by the errsatz mastering?".   If I documented the various processing necessary to get to the point of decoding, I could come up with a list of - maybe - 10-15 sox commands, maybe 20-30 command sequences.  'Re-processing' already released material is tedious at the least.  The other problem with decoding your own material -- without tones -- is to find the calibration level.  So, there is the problem of finding the proper calibration AND finding the corrective EQ (perhaps two filters, usually at 3kHz and maybe 9kHz), and determining the filter parameters.  There are MANY variables to reconcile -- if someone wants the hobby of decoding material -- go for it...  That 'hobby' (necessary to support the decoder project) has almost turned me into a crazy person.

 

I am NOT frustrated by most people in the forums not taking me up on an offer of a free decoder to use for a few months -- I only did that as a matter of politeness and avoiding the idea that I am keeping something away from everyone.   My frustration is that I had motivation to write the decoder, because SO MUCH material that I liked was not properly mastered.  (Secondarily, starting 4yrs ago, I didn't realize how damned difficult an approx 60 transistor circuit would be to emulate.)

 

So -- the above is my thought process.  I have NO resentment against audiophiles who believe (somewhat rightfully so) that it would be distracting to deal with decoding the material for themselves.  The problem for all of us -- the distributors who seem not to care about the quality of their product...   Then a generation and 1/2 of audiophiles have been purchasing poorly made product -- that IS my frustration, and I really want to help!!!

 

John

[John Dyson]

I thank you for the sentiments.  The worrisome thing (as a legacy issue) is that there are only two places in the world who have the source code, and a DolbyA decoder will never be written again.   If it was written in a large company, it would have cost approx $500K to write or not be done at all.  (Of course, my specs and the performance goals were much higher than a commercial product would be -- no reason to do the decoder if standards werent very high.)

 

Here are the problems with the project now:  1)  I had a dearth of listeners/testers, as I am not sufficient and my project partner has even more hearing problems than I do.  2) We had absolutely no support for software reviews 3) We had absolutely no support for proper testing of any kind.  4) Many of the publically 'released' versions had significant bugs.

 

All of the 'bug' problems are really solved -- I just removed the last two hacks in the code (there were two hacks intended to work around a behavior problem that has since been corrected.)   Unlike a true DolbyA -- the DHNRDS DA can line-up complex sounds from old recordings, and fully avoid the 'dithering' kind of sound and the decoding fuzz associated with a DolbyA decoding.  The software FINALLY meets those goals entirely.  I am afraid that too many people have seen the older versions -- but I needed criticism for testing/verification.  Also a lot of demo material has necessarily been already damaged commercial recordings.

 

Regarding the source code repository -- the DA decoder is truly a $500K development project if in the 'real world'.  There is new (patentable if I wanted to) technology in the decoder, and this intellectual property has to be managed correctly.  I need the energy/wherewithall to at least disclose some of the new techniques (they go far far beyond the Orban distortion avoidance patents), and even to properly internally document the source code.   The two copies of the software - in the hands of Richard Hess and myself, is fully dependent on two 'very gray hairs' and I am worried that it will disappear somewhere into the ether.

 

With the very slight amount of interest being shown (yea, a few recording engineers and maybe an recording archive site or two), there is not enough mass to be able to maintain the software and keep it in the public/recording world awareness.   I promise, the project and the software WILL die given the very terrible state of the recording distribution industry and the acceptance of really bad quality recordings - even from those spending multiple $10k on their equipment.  (Garbage in, garbage out, but the Emperor's new clothes stll apply.)

 

*  My own guess as to why the 'loudness wars' hit the high fidelity audio world stems from the DolbyA leaks and the totally cr*ppy sound of the CDs for the pre 1990 material.  That terrible quality decreased the standards of the listeners -- even the 'elite' listeners, also frustrating some of them into thinknig that 'all they need is better equipment'.   Of course, the problem has NOT been in the equipment as much as it is the horrid quality of the recordings.  Then, with the distorted standards, and the love for loudness for attention -- NOTHING pushed back on the loudness wars.   This lowering of standards started:  NOT DECODING DOLBYA IN THE DIGITAL BEGINNING.

 

John

[John Dyson]

9 minutes ago, lucretius said:

Is the second (processed) version of Please Mr. Postman a little bit less compressed?

It sounds significantly different -- actually it is a third generation beyond previous demos.  I'll run the carpenters albums starting now, should be done in a few hours.  I'll put up a few demos.  Believe me -- the original material (before decoding, sold as consumer product!!!)  is unlistenable (at least to me!!!)

1) there was a bug that I couldn't see...  2) I had workarounds in the code (the last two 'hacks' left in the code), 3) once I found the bug, removed the bug -- then subsequently removed the 'hacks' were forced by the bug.

 

As of now, the code is canonically provable.  No hacks at all.  I can now prove the code (at least the decoding math) for every component in a DolbyA unit.

 

Demos will be made available by about 7:00PM EDT USA time 4sep (I hope :-)).

 

John

[John Dyson]

2 hours ago, John Dyson said:

It sounds significantly different -- actually it is a third generation beyond previous demos.  I'll run the carpenters albums starting now, should be done in a few hours.  I'll put up a few demos.  Believe me -- the original material (before decoding, sold as consumer product!!!)  is unlistenable (at least to me!!!)

1) there was a bug that I couldn't see...  2) I had workarounds in the code (the last two 'hacks' left in the code), 3) once I found the bug, removed the bug -- then subsequently removed the 'hacks' were forced by the bug.

 

As of now, the code is canonically provable.  No hacks at all.  I can now prove the code (at least the decoding math) for every component in a DolbyA unit.

 

Demos will be made available by about 7:00PM EDT USA time 4sep (I hope :-)).

 

John

The DolbyA decoding (or DHNRDS DA decoding) demos are in the dropbox below.  I included .mp3 for convenience, but if you hear any swirls -- try the flac, the 'swirls' or 'phasing' won't be in the flac.

 

Caveat1: I 'decoded' the recordings from released 'consumer' material.  I did my best to 'undo' the ersatz mastering, and then applied the DHNRDS DA decoder to the 'prospective' DolbyA encoded recording.

Caveat2: I suck at 'mastering'.  If there IS a mistake to be made, I'll make it and embarass myself. We are NOT demoing my (lack of) mastering abilities :-).

 

The 'undecoded' material is 'RAWundecoded', and the 'decoded' material is 'V0.9.7K' - the version of the DHNRDS DA decoder used.

I'd suspect that with a true master tape, the results would be better -- usually with actual master tapes, the results are pristine.  However, when one starts with ersatz mastered material, and NO calibration tones, the effort can be daunting.

 

Each of the three examples comes from different albums, and I didn't re-adjust the calibration for each album (might have required minor changes), but it appears that the correction for ersatz mastering is the same for each album.  The 1969 and 1970 albums do seem to require a different correction, but these come from 1972 for 'Top of the World', 1975 for 'Please Mr Postman', and 1976 for 'Sing'.

The '13' version of Please Mr Postman is from the remastered singles available from HDtracks and elsewhere.

* There is a HUGE difference in the 13 version of Postman and the 04 version -- they ARE different.  'Postman' probably did need a remix, but '13' has too much compression (IMO.)

 

Here is the dropbox:

https://www.dropbox.com/sh/ciwfhzbhod3brnn/AABF1_QE7AVBOj0EGFe4KT5Ga?dl=0

 

[John Dyson]

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

 

[John Dyson]

There are two differences (but we probably don't hear hiss like I used to hear) -- there is definitely less hiss (look at the spectogram -- the whole purpose for DolbyA - not originally intended as a sound-defect.)  Next, the excess ambiance should be suppressed (that compressed sound, we are all used to hearing nowadays, is artificial.)   IMO it is a travesty that EVEN audiophiles are generally used to the damaged, compressed, especially unnatural sound qualities of undecoded material.   Our hearing accepts training for sound-defects very readily.  (Such training has been a major difficulity in my testing -- one reason why near the end of the project I had reached out for kind people like Sandyk, who might be more discerning than myself.)

 

Difference not caused by DA decoding: the high level transients are not changed much -- all 'action' is at -20dB or below (at MF frequencies) or a bit higher at the higher frequency bands.  It is the HF density damage (the unnatural dynamics) that are morphed back into 'more natural' dynamics.   You would only measure small increases in SOX crest factor, even though the peak-RMS ratio can sometimes be very significantly improved (1 dB improvement in peak-RMS is a very substantial quality improvement.)

 

It was that unnatural (but NOW tolerated ) compressed sound that turned me off back in the late 1980s -- the hiss didn't bother me all that much -- I definitely preferred hiss over DBX on tape...  I turned away from the HiFi hobby back then because the 'solution' to media quality (CD) ended up being worse than a well-maintained disk -- mastering issues.  One more thing -- when listening to the undecoded material, actually there has been EQ to suppress the HF boost from the compression.  My hearing has become trained to detect and know when to add small amounts of EQ in the 9kHz range -- the damage to such EQ is one reason for certain kinds of damage to sibilance.  (the 6kHz range is the most vulnerable region for damaged sibilance, and what is often enhanced in one way or another -- a great frustration when trying to DA decode such additionally damaged material -- basically ending up in the dustbin if I cannot correct that mess.)

 

We really need to get rid of the acceptance nowadays of that tolerance for HF compression.  It doesn't sound natural.  Of course no recording sounds totally natural, unnaturaly, HF specific compression is yet another defect that is artificially created.

 

Bottom line -- the difference in these recordings is probably much greater than the difference between a good $200 amplifier and a good $10k amplfier.   These improvements (generally -- not always, sometimes leaving in the compression DOES help) are much greater than moving from good quality electronics into esoterica.

 

The frustrating thing for me -- is that the audiophile should ALREADY be naturally purchasing the properly processed material -- yet will still spend 10X as much money for an amplifier that looks like a Christmas tree with single-color lights, yet IF there is a sound improvment it is 1% as much an improvement as properly mastered material.  The decoding mistake had started in the middle 1980s, and has created a culture that has morphed into a contributor to the 'loudness wars'.

 

I respect the individual perception of each person, but once one gets used to 'less damaged' material, then the damage & improvements become obvious.  Up until now, my patience was tested because I kept on improving the DA decoder, but it is truly 'perfect' now (as perfect as DolbyA CAN be decode -- which is still imperfect), and I am finally doing my *permanent* decoding effort (just started) for my library.  Otherwise, the contents of the library will continue to distract me for the (nasty) HF compression so common nowadays.

 

John

[John Dyson]

2 hours ago, lucretius said:

 

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.

 

I DID not peak level match the Olivia material -- it is now matched.  The Carpenters was already level matched.  But even IF one does match the peak levels, then the average decoded levels will tend to be less.  This is because the dynamics are cleaned up and the various signal components are restored to their proper levels.   DolbyA compression tends to INCREASE the loudness (to a lesser extent than the extremely aggressive compressors nowadays), and DolbyA decoding TENDS to DECREASE the loudness given the same signal level.

 

BTW -- I did NOT compare before and after decodes -- just checked to make sure that the 'afters' weren't insanely bad.

 

John

[John Dyson]

2 hours ago, pkane2001 said:

 

There appear to be a couple of notch filters, in addition to a slightly lower level above 8.7kHz and a couple of unexpected 2dB dips at 8.9k and 9.8k:

 

Here's the same plot with the undecoded file on top:

 

[John Dyson]

Those 'notch' filters are essentially an inaudible error (I made a mistake in a sequence of filters in the demastering correction in sox.)  I skipped a few 500Hz bands -- I can hear ZERO difference in that kind of case.   Many times, my quick manual runs have run the correct demastering sequence -- depending if manual or not, and depending on what album is being decoded.   Except for the notches, any 'dips' are corrections against ersatz mastering.  (Attempted correction by the distributor to do EQ making compressed DolbyA material sound tolerable.)   I thought that I had fixed the filter sequence -- but there is a different set of filters for each group. 

 

It is a NIGHTMARE to deal with feral DolbyA material.  I try hard, but my mind/focus isn't on it -- and make mistakes every time.  Also, I maintain at least one script per album, a set of correction functions for each group (usage dependent on the album.)  Then, when I am testing with the material from one group, often I forgot about a loose end when going back to another one.

 

I have some more explanations for any other (no-notch) bumps in the response, but it is basically demastering (correction of ersatz mastering.)

 

On the before and after, where there is a diminished level at low levels -- that is to be expected.   The higher levels are maintained.   The lower levels are subject to the downward expansion in the DolbyA decoding.

 

I'll do a rerun without the filter mistakes -- you'll hear ZERO differences (but the mistake is NOT a good thing anyway.)   I suck at mastering -- I make major mistakes EVERY TIME I atttempt.  My mind is usually on the wrong thing -- thinking about what is happening in the decoder, instead of actually using it.

 

I am currently doing a massive, multi-album test decode of another group, but will do the 'Take me home' again to show that it is easy to fix.  I don't think that ANYONE will hear a difference (but my mistake is truly a mistake.)   It will be tomorrow morning before I can produce 'Take me home' again, and a few hours to do all 48 cuts at the highest quality level.   (The EQ error was before decoding.)

 

Give me access to any true master tape (with tones) in your possession (I'll sign an NDA), and I can show how pristine the decoder works when starting with properly maintained/unprocessed/undistorted material.  I cannot share my own copies of proprietary materials (even 10seconds worth.)  I made a personal guarantee - but it is very difficult to find material with tones in the public arena.

 

John