'FeralA' decoder -- free-to-use

[Jud]

Must it be a WAV file from a CD, or can it be a WAV file that I'd convert from an AIFF rip, for example? If I ever get some time, I might try this on a track or two from the famously ruined-by-bad-Dolby "Katy Lied" by Steely Dan.

[Jud]

28 minutes ago, John Dyson said:

I am offering my ONLY A/B comparison that I JUST GOT several days ago.  Someone on Hoffman helped me...

 

One is old, pure vinyl (but ticks and pops).

The other is the decoder output...

 

Other than the bad surface effects, doesn't the decoder sound as good or better?

After some things that I have recently read - I wouldn't be surprised if many wouldn't prefer the VINYL version.

 

This is what makes me cry -- it is so obvious that the decoder IMPROVES the recordings, but perfectionism is delaying better/more clean/clear listening...

 

Just listen to these -- they are short, simple and obvious....

 

VINYL (non FA):

JustOneLook-vinyl-snip.flac 2.68 MB · 2 downloads

 

DECODER (from CD):

JustOneLook-dec-snip.flac 1.71 MB · 1 download

 

 

 

 

John, I'm very late to this, so forgive a stupid question - What does it matter what the decoder does to a needle drop (if I'm understanding correctly)? Are you saying this vinyl was recorded with "feral" A processing?

 

One other remark: I've listened to a few of the J version smippets.  The vocals are outright stunning.  I'm not sure about the midbass, though I'm listening on two little Pioneer desktop speakers (good enough to sound really good with good input, though), so that could be it.  What I mean is that I can hear the dB level of electric bass (for example on Here Comes the Sun) dropping as the frequency goes up.  It's not that I'm missing the old distorted bass, but rather that the level of the bass should be internally consistent over frequency within the same song.  This could be a problem with the crossover levels in my speakers - I'd have to listen on my main system to be more certain.

 

Are there test signals you can run through the decoder to see whether I'm off base here?

 

 

[Jud]

@John Dyson First of all, Happy Easter!

 

Thanks so much for your consideration of my reply, and your work on the bass.  I have to say, with apologies, that it is difficult for me to tell on a casual listen that the new decoding is necessarily correct/better.  It sounds to me as if the loudness of the instrument is more consistent over frequency, but I can't be certain.  Just because of McCartney's bass line on "Here Comes the Sun" (intended to be in the background - therefore not emphasizing certain notes as part of the rhythm, as the bass does in Just One Look), it's easier for me to hear consistency in loudness over frequency range in that song.

 

I was wondering if it would be possible to do something like the following: 

 

- Use a candidate decoding on Here Comes the Sun

- Isolate the bass line after decoding using filtering/EQ

- Graph loudness vs. frequency for the bass line

 

Was just thinking, even though humans are actually pretty good at judging loudness in certain situations, surely a measurement would provide greater reassurance.  It would be a measurement of consistency across frequency within a song or part of a song, and therefore not prey to the subjectivity of "Is this the most natural sounding level of bass for this song?"  It would not necessarily let you know you had the overall bass level correct, just that if all the 50hz bass notes are louder than all the 100Hz notes in a bass line where particular notes are not being emphasized as part of the song structure/rhythm (i.e., the bass line is one where the notes are generally intended to be of similar loudness), you know there's a problem.

[Jud]

Very quick impressions:

 

First, you did no harm to the glorious vocals, and perhaps even improved them a touch.  Just listen to the two versions of The Sound of Silence, no comparison in terms of how much more I subjectively enjoy the decoded one.  (Don't know if there's a difference in overall loudness - if so, that could be at least partially responsible.)

 

Second, the problem with the bass has been ameliorated somewhat but not totally to my ears.  On "Here Comes the Sun" (noting before I go any further the naturalness of the guitar and the lovely treatment of George's vocal in comparison to the raw snippet), just concentrate on McCartney's bass line.  It seems to me the overall bass level has gone up relative to the last decoder, and the lowest notes may even be the slightest touch bass-heavy by now.  But listen to how the volume of the bass in the decoded version diminishes as the frequency of the notes goes higher to a *very* noticeable, to me unnatural, extent.  Compare to the raw version - the bass notes are much closer in volume over the frequency range.  Not precisely equal, but not diminishing to nearly the extent as the notes go higher as in the decoded version.

 

Again, this is just a quick listen on desktop speakers, and obviously a subjective impression.  I don't know if measurements would show that impression to be correct.  But that's what I'm hearing.  It's great stuff overall, but I'd love to hear the higher bass notes sounding a bit more equal to the lower bass notes if that can be done without mucking everything up.

 

(Just to note that the overall subjective improvement is so marked I feel a bit ungrateful voicing any criticism at all - it's solely in aid of helping things improve if possible.) 

[Jud]

This is very, very good (subjectively speaking of course) at this point, good enough that I would trust measurements (if there are informative ones to be done) over my own hearing.  So take this comment in that vein: I feel there may be either a bit missing at the top end of the human vocal range, or else something near that frequency is emphasized and so the very top end of the vocals feels a bit hidden, relatively speaking.  I don't actually know whether that subjective feeling is accurate, whether I'm accustomed to some inaccurate overemphasized "air" in that range, or even whether I'm hearing things that aren't there and measurements will demonstrate to be nonexistent.  Of course it could also be my desktop speakers - I haven't had the time to download snippets and run them through my main system.  And I'm not talking about the decoded snippets versus the raw - there *is* no comparison there as far as I'm concerned.

 

The comment is only because I'm trying to be hyper-alert to come up with some possibly useful remarks - I'm really enjoying listening to these snippets.

[Jud]

11 hours ago, John Dyson said:

Good description

Yes -- there is a high end problem -- I slipped in an new 2.2.4F version to fix it -- I am no longer announcing the releases, because the changes are so small now.   Most changes are close-in adjusments are minor error corrections.

 

Here is the trouble (it might be what you are seeing):

There is a necessary 3k to 9k 1st order pre-emphasis, along with a 9k to 18k decrease  total:(3k +9dB, 9k -6dB).   On the 'flip-side' for the de-emphasis, of course, there needs to be a 3k to 9k decrease (-9dB.)   The problem side is 9k to 18k.    The complicating factor is the 9k to 20+kHz band, which effectively gives a gain of +6dB, but it is dynamic.   What should the 9kHz to 18kHz de-emphasis be?   When looking at this from an engineering point of view (and understanding filters), it seemed like a de-emphasis starting at 9kHz * sqrt(6dB) would be the correct de-emphasis frequency.   Well, that was wrong.   Basically, there should be NO de-emphasis for the 9kHz+ band.   It is all taken care of by the DolbyA '9kHz +5dB boost'.   *The reason for the question/confusion is that the choice of the de-emphasis AND pre-emphasis is based on what the original designer chose*

 

The effect of my erroneous EQ (yes -- I take ownership for my mistakes) was to enhance the 9kHz maybe up to 16kHz frequency region, because there was also a 16k decrease.  I know that this is goblety gook -- but basically it all adds up to a bad 9kHz to 12kHz (maybe a little higher) approx 1.5dB boost.   Even the smallest error like that sounds REALLY REALLY bad.   I  went through a few days of bad HF hearing, so I didn't catch it.  I just got my ear-full on some orchestral stuff -- the violins were almost dissonant -- my hearing came back.

 

* We are at the level of very small changes now.   This might even be the last change, maybe not.   The reason why I am pulling back is that there is more to do, and SOME work needs to be done privately.

 

This thing is a mix of engineering knowledge (thank goodness I do deeply understand DolbyA), and also double checking by listening/hearing.   Sometimes my hearing fails -- and yes, sometimes my engineering guesses fail me.  My hard engineering is really good -- but my guesses could probably be better.

 

See if this 'V2.2.4F' is more tolerable.  I guess that I probably should do snippets again -- look for the new snippets with the correct "V2.2.4F" version (probably in +3Hrs.)

 

BTW -- I'll be checking for questions in the morning about this time of the day - maybe a little later.   I'll be focusing on some new anti-MD code along with code-sanitation so that I wont be embarassed for others to see it...   Been lots of changes -- it was SOOOOO nice to remove that LF EQ trash though 🙂

 

Thanks -- chat later.   Let me know what you think, and I'll try again.

 

 

 

 

I like the G version a lot.

 

As @PeterSt likes to say, if you listen and say something like "The vocals really come through well," or "Great detail from the strings" - really, if any separate component calls attention to itself - then something is wrong.  I didn't come away with an impression that a particular piece of the rendition was outstanding or diminished, just that the entire thing was very natural and musical, and compared to the raw versions, clearer.

 

All quite subjective, of course, but that's what it sounds like to me.

[Jud]

I know for darn sure I can't hear .35-.50dB in the middle of other music, because I've tried test signals and distinguishing a .4dB change was extremely difficult for me, right on the edge of what I could (at least consciously) perceive.  So take the following with a large degree of skepticism: The background (for example, bass) in the current H versions, as of 10 pm and a little later US Mountain time, seems elevated in respect to the vocals and the rest of the midrange, which now seem to be relatively a little reticent.  No idea whether this subjective impression is accurate at all.  (I note the snippets page says "Correction Coming," but for all I know it's already occurred.)

[Jud]

I know everyone likes to gawk at fights, but perhaps this once we could sit back, let John do his work, help him in the way that is most helpful to him; and meanwhile, see what can be gathered from the critiques that may eventually in some fashion prove helpful to John, since I think all agree that the goal is worthwhile.

 

I don't know if KSTR is posting any more, but is the basis of the critique that all these files cannot have been screwed up so much and in roughly the same way, and that therefore an attempt to "unscrew" them to such an extent and in roughly the same way cannot be correct?

[Jud]

10 minutes ago, John Dyson said:

I think that they are close enough that some SIMPLE comments might be helpful

 

John, I'm not sure Peter does "simple." 😀

[Jud]

16 minutes ago, John Dyson said:

Thank you for your lack of help, thereby necessitating a risk to health.

 

That kind of thing is just "not on," to use a British-ism. Responsibility for your decisions is yours, John.

 

Agreed with MarceINL that we should be talking audio projects here, which to me is the interesting stuff.

[Jud]

3 minutes ago, Don Hills said:

Even assuming that someone did build a compressor using cascaded Dolby A encoders, it can't be in common use. If it was as widely used as you believe, they would be ubiquitous - found in almost every studio. A secret that big could not be kept.

 

My picture of this is of recordings long since made and sitting in labels' "vaults," so to speak, and one or more people coming up with an automated process or processes to run them through.

 

Very obviously processing that substantially altered the sound of old recordings was taking place at virtually all the major labels. One look in DR Database at re-releases of older recordings will tell you that.

[Jud]

1 hour ago, John Dyson said:

When doing the FA decoding, in previous versions, the vocal was 'buried' deeper than it should be. 

 

Something I've noticed and had mentioned to you. Glad to hear progress is being made in that area.

[Jud]

2 hours ago, PeterSt said:

Where are those other people ? anyone ?

Me for one, as I get little snippets of time here and there. When I retire in a few weeks I hope to have more time (but of course my wife may have other plans).

 

 I mentioned to John what you did, that the latest were improved. And then in fact I suggested he would likely get constructive criticism/feedback from you.

[Jud]

3 hours ago, John Dyson said:

(COVID is kicking my a** right now, or the full release would have been today/tonight.)

 

Damn! Get better soon, John!👍

[Jud]

2 hours ago, John Dyson said:

I am working really hard on the project, hopefully gonna make the demo later on today.  Trying to figure out the bugs, testing the EQ on REALLY DIFFICULT recordings.   Katy Lied is most interesting!!!   A 'plausible' demo could be uploaded now, but I am trying for an actual high quality demo.  If it takes another day, please be patient with me.   Both 'time' and 'frequency response' need to be considered, and there are some really tricky things. 

 

John

 

 

Katy Lied results will be very interesting indeed. Been wondering about how that might work out since I first learned about the project.

[Jud]

1 hour ago, John Dyson said:

When the upcoming decoder version & demos are produced, the problems with 'Katy Lied' will become apparent.   It still sounds good, but decoding is problematic.   One might suggest that the recording isn't FA.   That might be possibly true, but I hear no associated artifacts against it being non-FA.

 

Quote from the "gremlin" article: "We were using the new dbx noise reduction system, which was supposed to give us a better signal to noise ratio than Dolby...."

[Jud]

3 minutes ago, Jud said:

 

Quote from the "gremlin" article: "We were using the new dbx noise reduction system, which was supposed to give us a better signal to noise ratio than Dolby...."

 

Some discussion about dbx noise reduction: https://recording.org/forum/recording-live-or-studio/dbx-noise-reduction

[Jud]

Wondering if the fact that dbx rather than Dolby A was used on Katy Lied is responsible for some of the decoding quirks. Or should the decoding work for dbx as well?

[Jud]

11 hours ago, John Dyson said:

Each use  is independent.  (tape NR vs. FA encoding/decoding).

DBX is an encode/decode process for recording on tape.   Primarily, DolbyA is also.

 

In conversation, DolbyA being used as a part of FA often does get confused with DolbyA being a noise reduction system.   These are independent usage of the same kind of hardware.'

 

Right, understood that part of the Dolby A process is being used on these recordings not as noise reduction but as flavoring.  (I used to do that back in the days of cassette tapes and I imagine others tried it as well.)

 

What I was wondering was whether the dbx noise reduction on Katy Lied, being a separate thing from the Dolby A flavoring the decoder is designed to deal with, might have led to some of the anomalous results you're getting when working with that recording.

[Jud]

1 hour ago, John Dyson said:

If the 'odd stuff' is really necessary, the FA encoding is really not intended to ever be decoded.

 

That would make sense if, as is the case, the encoding was intended as a flavoring rather than noise reduction. So not taking away the bits that were intended to be "punched up," while removing some of the more deleterious side effects (hiss, lack of dynamics, phase/stereo image) would be overall a good thing.

[Jud]

32 minutes ago, John Dyson said:

This makes me wonder why consumer expansion devices back in the 1980s -- why didn't they use the descrambler scheme?   It is easier to do in analog HW than in DSP, why not do it in analog, giving superior results?

Because then it wouldn't sound as punchy on a car radio.

[Jud]

6 minutes ago, John Dyson said:

I meant, the consumer expansion devices intended for the dissatisfied HiFi consumer like 3BX or somesuch. 

Possibly quite wrong about this because I'm basing it only on my personal anecdotal experience, but perhaps (lack of) marketing, because I was only very dimly aware of anything *bx and thought of it as pro stuff. Dolby pretty well dominated consumer compander mindshare for me.

[Jud]

2 hours ago, John Dyson said:

personal hospital matters

Please take care and be well.

[Jud]

2 hours ago, John Dyson said:

Didn't complete the message, sorry...

I simply cannot function well enough to do the release tonight.   Probably one of the reason for the delays, just cannot get my act togehter, get in the zone, etc.  Not in a bad mood, but having problems regulating it very well.  Even after having COVID before, I am hurting in ways that I never have before, not likely at the cancer level, but more like serious overuse time pains.   Even my hips/back hurt, and I am very physically strong (little endurance though.)   Where is the pain from? 

 

I PROMISE as soon as I can reliably do what is planned, I will do it.

Even if still sick, I can make progress, but very inconsistently.

 

Please forgive, and very sincerely,

John

 

Just be concerned about getting well. 👍🏼

[Jud]

Best wishes for your mother, John. Take care.