Valuable Resource

[Robert]

I did wonder about all of this when I checked out Led Zeppelin remasters which didn't do very well on the DR site.

I owned a German pressing of LZ 1 CD and when the remasters came along in the 90's I got hold of a German pressing and after extensive listening comparing. I felt the remaster was definitely better.

I mention German pressings as these were always superior to our local pressings we got mostly made in Australia.

Regarding Crime of the century I only ever owned the vinyl not the original CD so was not able to compare original with the MFSL download I currently have. I was put off downloading the remastered version due to adverse comment on download sites re the so called 'loudness wars'.

I thought 'loudness war' was created for radio and small sound system playback Ipods etc to attempt to create a big open dynamic sound. Its practised in radio stations and studio's. 

I have always been wary of remasters being better and listened before buying. Although, I so often like the music, I would buy it anyway even if its only marginally better.

I also note no Golden Earring albums have been tested for DR.

[Jud]

I think it still pays to be careful.  As you said when you were thinking of how to implement something like a dynamic range measurement in XXHE earlier in the thread, it isn't necessarily as simple as determining what the difference is between the very loudest and very softest milliseconds of the track.  Headroom and lack of it, leading to clipping or limiting of the widest swings, is a reasonable factor to consider. 

On this Supertramp recording it may give anomalous results.  But on the R.E.M. recording I bought recently ("Part Lies..."), it's quite evident that it's just been made too damned loud.  And the highly touted Nirvana remasters turn out to be compressed as well, for me removing much of the drama of the groundbreaking "Nevermind" album.  The database shows what I hear for these recordings.  It's one factor that may be considered, and it's a factor that in some cases at least can be considered (along with other information) *before* purchase.  Not that it can't be or shouldn't be improved, though.

[PeterSt]

[brainstorm !]

I'll try to explain a few things :

I am not sure whether it is really a known phenomenon, but at least I recognized quite some years back that when we have a CD which doesn't use the headroom by far, it sounds more dynamical. More open. More air. More depth. More everything. I reported so on this forum as well (somewhere in between and not much as an explicit subject).
This is about the headroom utilized at 66% or so (EAC reports on this during ripping, so you might recognize it).

When you look at this at first glance, this makes no sense. So, less headroom utilized means less dynamical range in order. Notice though that this 66% would imply something like 4.5dB only. So, this is not *that* much difference and therefore fairly harmless. Still 4.5dB less, but harmless in my view. BUT :

It would kind of guarantee that no compression has been in order. How ? well, if I were this mixing engineer and finalize the album or track, and I would use compression, then I would do that with as much speace as possible. So, 100%. Not 66%. That would be the stupiest thing to do. So ... when we would take it as a "rule" that an album which doesn't utitlize the 100% but far under that (which would be this 66%) and put out a "DR meter" figure on that, the 66% would receive a say, 20. Now, to me it looks like DR operates on just that, and nothing more of intelligence. But now think :

When the recording is calibrated precisely and no single peak extends the 100% but just under that (impossible for a live recording) then the DR should be higher than the same recording reasing 66% only. But DR doesn't accept this "rule" and the more of the headroom is used, the worse it's figure is going to be. This, while it should be better.
My little Crime of The Century test emphasizes it; The at first utilized Dynamic Range was squeezed and squeezed (just by attenuating digitally, loosing more and more bits) but the DR figure remained. Only when almost nothing was left (see picture from before previous post) it dropped by one number.
And so I say "worthless".

A remaster like that 2002 from Crime of The Century : the level is taken up so the theoretically available Dynamic Range is utilized better, but it gets even more better when the handful of occurring peaks above the 100% are limited (read : almost cut-off hard) so the remainder has more dynamic space. This is not bad; only those handful of peaks are out and you may never notice it; and when you do, it's still about those handful of peaks only.

A remaster like "The best Disco Ever" (just making up one) : The level is taken up way more, and now each second will contain peaks above the 100%. This can't be limited anymore because it will be audible as distortion. So now it's "compressed". The louder the level the more it's compressed and this goes by various many settable parameters. It changes the music and what happened to the wave - which looks flattened - happens to the sound just the same (sound flat). Here, really the Dynamic Range has been narrowed, but now by different means than not utilizing the space;

In the case the original take utilized 66% it is not said that you will perceive that roughly 96 - (96 - 4.5) = 91.5dB minus noise of 30dB = 61.5dB. It will when it's a drum track (from silence to max-hit) but it won't when it's this choir singing nicely all the time; the choir may sing at 30dB above the noise anyway. So, perceived dynamic range of the choir is 31.5dB (61.5 - 30).

When this is carefully recorded, 4.5dB is added and peaks are just at 100% (not over it). Choir is now 31.5dB + 4.5dB = 35dB of dynamic range.
Drums would be 61.5dB + 4.5dB = 66dB of dynamic range. Notice that both have an absolute value of 66dB max, but drums start more down because they start in silence.

Now we make Disco of the combination of choir and drums;
Drums don't start in silence because the choir sings at 30dB (above noise) to begin with (softest). Besides, drums are way louder and should sound louder. So say that the silence level of the drums now is to be the level of the choir singing the softest. So, dynamic range of the choir was 35 and dynamic range of the drums was 66;
35 + 66 = 101, but technically there was also the noise of 30, thus 131.

131 does not fit in the 96dB which is technically available in digital, so something has to happen.

Did you follow so far ? the latter is how I described the recording process of today, which is the same as "remastering". It starts upside down. And earlier ? earlier, virtually (!) the volume was taken down with 35dB (131 - 96) and the fun is : now the choir has gone. Virtually, because when the recording was analogue, all what happened is that the drums were louder for excursions - hence dynamic range was larger. Now, in digital (16 bits that is) this can't be. So, solution ?

Cut off the tops ! haha
hmm

So, the top parts are a kind of gently compressed, but mind you, in my example (for what that's worth) with 35 dB. The gentleness causes much more to be compressed because otherwise it would be cut-offs. And so everything is squeezed and the more loud the more. This makes the choir still to be audible, but the dynamics of it all to vanish. And, overall the sound (SPL) becomes larger.
The perceived (but it's literal) dynamic range has become less.

DR reports on this.

When I lower the utilized dynamic range like I did it with Crime of The Century (remember, just attenuate it), that perceived dynamic range can sort of stay the same. All the lost bits were in the noise anyway (that first 30dB of acoustic noise) and maybe not so much has been lost.
Hasn't it ?

It has, because when I expand that later (just louder volume) the resolution in the level(s) has gone. Before (in the case of Crime of The Century) some 27000 decimal steps were available (so, 27000 utilized of the 32767 available) while now there's only 3000 or so steps available. It is clear that this implies a huge roughness (and sheer distortion), never mind the theoretical dynamic range still being the same (say, when it is remapped to the full 100% again).

Notice that this Crime of The Century already exhibits this distortion (to me) with this 27000 utilized.

What DR does, is holding the RMS value (which is the average level) against the peaks. The difference of that (with some proper math) gives the dynamic range (like I tried to describe with the choir singing at softest). Should be around 0 for a choir because no peaks are there. Anyway, when making Disco out of it, peaks will be there because of the drums;
RMS will be lower when attenuated like I did, but drums will peak as much above the RMS value as before. Dynamic range stage the same for that (and now I think of it, lost bits at the bottom (is lost lowest levels) will hardly matter -> only contributes a little to RMS which goes up now).

My conclusion :
DR may show the dynamic range all right. But it says nothing because :

1. It depends on the music itself (drums-only will show best figures);
2. It is wrong to hold the RMS value against the peaks without incorporating the absolute levels.

Ad 2 (a)
When this is done, a subjective quality factor could be incorporated. This should rate my attenuated Crime of The Century to 0. Ok, 1 for the trouble.

Ad 2 (b)
This is more complex than it seems at first glance, because when on one track is a choir and on the other is those drums, the choir can only ("over"-)improve on resolution when it's made (recorded) louder. This is not the intention and so maximum levels are just OK here. Now, at this time I really would not know how to discover whether it's just a poorly utilized headroom (implying unnecessary level distortion plus unnesessary noise (because the volume has to be cranked up)) or that it's just an in-balance (choir) level compared to the next track which is drums.

Sorry for the brainstorm,
Peter


PS: I should add explicitly that although XXHighEnd doesn't provide any DR number, it's problems actually come down to the same. Regarding this I should notice that I'm not bashing on DR, but it may have looked like it. But also : in my posts which I scratched again because they were no good, I already said so (XXHE being as "bad") but this context had disappeared of course.

[Jud]

Sorry for the brainstorm

Not at all, it was terrific stuff, very understandable and informative.

But (always one of those!) I think, even with the very evident problems with this DR measurement, there are circumstances where it is informative. 

The one I always come back to is Nirvana.  If you recall their biggest hit, "Smells Like Teen Spirit," it juxtaposes quiet sections with Cobain singing fairly softly, playing individual notes on the guitar slowly and rather softly with a bit of vibrato, with sudden transitions into Cobain almost screaming (still in tune, though), power chord guitar, bass and drums wailing away at top volume.  Those transitions give this song and many other Nirvana songs a lot of their drama.

What the remaster did is raise the volume level of those relatively quiet passages.  The transitions aren't as big a change, causing the song to lose a great deal: there you are anticipating the big entry of the screaming vocals, guitar, bass and drums, but the entry is not so big any more.  So when DR Database shows the 1991 CDs with a DR of 11 or 12, while the "Super Deluxe" 2011 version and HDT download have a DR of 7, that's what's happening. 

I do understand with the DR methodology there will be situations like Crime of the Century (which I'm very familiar with - one year in college it was a couple of my housemates' favorite record) where the initial recording was in effect too quiet.  But that's not what is happening with albums like Nevermind.

So is there any way to say whether the Crime of the Century scenario or the Nevermind scenario applies in a given situation?  Perhaps there actually may be.

One reason a recording may have been made without utilizing the available headroom is because of the physical limitations of vinyl.  It was quite normal before the advent of CDs to limit dynamic range to what the vinyl/stylus system would track at, and what the possible groove width was, for the loudest bass notes of a given track.  (Something I noticed on the Beatles remasters is that McCartney's bass is definitely louder.)  So there we may have the Crime of the Century scenario, where the CD format has more available headroom.  But where previous CD issues have substantially higher DR numbers, especially where (1) the earlier DR numbers are themselves middling, and/or (2) the recording was first issued on CD, then I think it is quite likely we have the Nevermind scenario, where it is not the limitations of the LP that dictate, but the fact that even the softest parts of the song must be made loud enough to be clearly audible over standard issue iPod headphones on a crowded city street or through a car radio.