Recent talk about mastering quality has compelled me to commit this to my blog:

http://audiamorous.blogspot.com/2008/09/wa...ed-harmful.html

Summary: Anybody who waves an Audacity screenshot around saying how good/bad a mastering is will be summarily punched in the face.

I think one needs to differentiate here.

Amplitude graphs are a very good way of explaining the problem - the overall principle. But they may not be a good way of measuring and detecting it in practice.

So does that mean that when you correctly rip a CD and get waveforms that look like the following, that they may actually be ok?

I ripped this a few days ago and frankly I was horrified. I thought it must be trash, like some sort of audio vandalism where the person doing the mastering must be a clueless loser. Can it really be that the people mastering this stuff do actually know what they’re doing and that they are carefully monitoring the distortion levels that are caused by this clipping and keeping it within some acceptable bounds?

EDIT: Massive self edit to save falling out with Axon. If you are the author of that piece and I haven't seriously misinterpreted the suggestion that deliberately adding clipping to a waveform is in any way acceptable, then you really don't want to hear my opinion on it! All I will say is that it artificially generates a stage of lossiness in a digital system that is perfectly capable of being, to all intents and purposes, lossless.

Cheers, Slipstreem.

You can hardly tell people not to use waveform plots, and prove the folly of this by using a waveform plot...!

The point is not to misinterpret them. As you have shown here...
http://2.bp.blogspot.com/_biABNEep_j0/SMYs...yendecker-2.png
...waveform plots, carefully examined, can be perfect for teasing out what has really happened. Not always, but often.

btw, I have CDs where the "clipped" peaks look exactly like the clipped peaks from your vinyl example, because the clipping occurred before other processing. I found such "clipped" peaks because I heard the problem, and went looking for it.


I don't have the Bob Katz book you quote, but you appear to misuse the quote itself...
"reduced by 4 to 6 dB" does not equate to "clipping".

DC shift aside, runs of clipped samples are effectively muted samples. There is no audio there. So the question becomes, if you hide the DC shift, how many samples can you set to zero before the effect becomes audible. This is quite well researched in psychoacoustics - the answer is totally content dependent, but it can easily be a couple of milliseconds or more. This is for something like white noise, with a single mute - not a repeating pattern.


Most listeners have speakers that will "change the timbre" dramatically more than any record producer would choose to - that doesn't mean that those of us with decent speakers should also have to suffer.

Funny, I use my own ears, not someone else's!

I think the kind of music that's trashed today would probably have been trashed in a different way had it been made in the past. Many (not most) pop records from the 1960s were fairly lo-fi. However, it's quite easy to find recordings from the late 1950s which sound far better on a decent stereo than typical modern pop recordings. The chance of being able to listen to a pop recording on a decent stereo and actually enjoy it is probably lower now than it's ever been.

Cheers,
David.

Exactly. And the thing I find hard to understand is why the heck anyone would want to make that compromise for an extra 3 or 4 dB gain when we've now got a thing called an amplifier and volume control!

The crazy thing is, if it was 100 years ago and we were all listening to records played unamplified though a passive horn with no volume control then it would actually make sense to make a compromise like that.

Maybe this is what the modern producers think were now using

hmm....manually compressing a face....that's a little extreme



I think it would be more accurate to say, subjectively 'bad sounding mastering' can usually be convincingly correlated after the fact with some quality of a waveform or spectral view; but be careful going the other way -- I have seen people tout waveforms with relatively minor, and likely inaudible, amounts of clipping, as proof that the track sounds bad.

What 'sounds good' is so highly influenced by audio and non-audio factors that I really have to wonder whenever I read rave (or neg) reviews of music these days. Example: since I began ripping DVD-As and 'laserdropping' SACDs, it's been illuminating to look back and see how many of these often highly compressed (though rarely clipped) stereo versions were praised to the skies as the best ever masterings so far...by people who claim to loathe compression when they see it on CD waveforms. To me, that's gotta be some combination of expectation bias (hi rez = good sound) and actual pleasure with the sound.

As for 'ask a mastering engineer', and using Hoffman as a paradigm, given his lifelong aversion to digital (he wouldn't even make a single digital edit to join the two masters of side one of 'Thick as a Brick', claiming it degrades the sound), and some of the bogosity he's spouted about it, I'd hardly consider him a go-to guy on the matter. I'd go to Katz, who actually accepts that digitally compressed audio can still sound great.

Have you posted your links and thoughts in a thread on Hoffman's forum? That should be, um, interesting to watch, if so.

So I'll start by saying that I wrote that entire post between the hours of 1-5am and I was more than a little punch drunk. That said, I would like to clean it up and distribute it more widely (once a ton of stuff is fixed).

Thanks for the responses y'all.

It's possible, but a lot depends on the context.

Clipped sine waves - and more generally, periodic clipping - tends to be fairly horrifically audible; the clipping harmonics extend so far out of the original signal band that the sensitivity to that sort of thing is tremendous.

OTOH, clipped transients - in the limiting case, something like a single clipped sinus - are relatively inaudible, because the transient content is so smeared in the frequency domain to begin with. At a high enough level, you can reduce the power enough to cause a dynamic range reduction, and/or change the timbral character of the transient, but it's not exactly something like "shave 0.1db off and you'll have serious problems." Whereas shaving 0.1db off a sine wave is a very big deal.

In the context of your waveform, the big clipping sections are 13ms apart, which sort of implies a large 76hz component - some sort of drum work, I'd completely guess? If it were a bass guitar you'd clearly have issues, but if it were percussion, I could go both ways on this. On one hand, the clipping is only about 1-2ms each time and it looks vaguely about 3-4db down from true peak. OTOH, the low frequencies involved, and the expected resonance of the drum, means that the clipping may be almost tonal in character. And when the clipping does happen, the harmonics will start at 152hz and plow on up from there.... which could totally suggest a sort of "congested" feeling in the music - which I'm guessing you've noticed But that could just be expectation bias talking.

I'm switching sides so fast it's making my head spin. One of the points I'd like to make more clear in my post is that there really aren't any silver bullets here. That is, it is plausible that in some cases, the mastering engineer knew what he was doing all along, and that the clipping is not audible. In many other cases, the exact opposite is true. And there's really no completely trustworthy way of telling the difference, with a computer tool, yet. Follow your ears, I guess.

Dude, I was kind of expecting to be walking into a hornets nest on this one. As I mentioned above, my argument for the inaudibility of clipping is more or less restricted to strongly transient content.

That post needs some serious quote-tag validation, dude. ;>

The max is ten quotes per page. If you want more you can post in pieces and if you do it quickly enough they will be combined.

I apparantly discovered that independently, greynol. Thanks.

Good catch. I worded that in a perhaps far more inflammatory fashion than I probably should have. Still, I would like to make it clear that waveform plots are very untrustworthy. Even those zoomed-in plots, at a cursory glance, seem to confirm that the dynamic range is higher on the vinyl version - quite a few clipped regions on the CD do not show any obvious signs of clipping in the vinyl. So I think I can still reasonably end the title with "Considered Harmful".

That's great, but you're also a competent, professional audio engineer who knows what to look for

Truth be told, I don't have it either. I got lucky on a google search and came up with the quote in Google Books. I might have a relative who has it though....

I will admit to equivocating between "clipping" and "brickwall limiting" here. In my view, they are largely two implementations of the same basic concept - it's just that clipping tends to generate a lot more high-order harmonics than brickwall limiting. Is that kosher?

As mentioned above, periodic clipping is obviously a much bigger issue than aperiodic clipping - and periodic clipping clearly happens a lot in modern mastering, and it sucks - but telling the two apart is, I believe, quite important, and rather difficult to do with a visual analysis.

... also, you know, for a psychoacoustic result that is so well known, it's damn hard to find information on it online. I think I spent half an hour looking for documentation on this sort of thing, and the only reason I didn't search for a longer time was that I've done this search before and came up relatively empty-handed.

Any additional information you can provide on the audibility of clipping/limiting would be greatly appreciated.



No, but it does drastically reduce the perceived importance of clipping distortion. People care when information that is "rightfully" theirs - the dynamic range of the performance - is robbed from them. I don't believe they care as much when the drum set doesn't sound right. There are tons of successful albums out there that, IMHO, have ridiculously bad sounding percussion.

Quite frankly, I believe that dynamic range changes and distortion increases are Big Deals that can persuade people, but timbral changes are not going to persuade anybody outside the audiophile set.

Bah. Don't make me shout TOS8 at you. ;P

Actually, SRSLY... I do have (legitimate) access to a multitrack recording session of a rock group, and a reasonably professional mixdown and master that manages to squeeze 9db off the peaks. Would you or anybody else be interested in some ABX work to see how much limiting can be applied before audibility occurs?

And yet..... it's still done. A lot.

That's the biggest paradox in all of this that really makes me question how important talk of the loudness war really is. If it really were as bad as everybody says it is, people would not be listening to modern music nearly as much as they actually do. But the teeny boppers are still listening to the Jonas Brothers and Hannah Montana (at least they do in Texas - I dunno what's going down in the UK), and they seem just as thrilled about them - even in the recorded format - as kids from previous generations have been about "their" music. I have yet to see any kind of conclusive evidence that declines in the music business can in any significant way be the result of compromised audio quality.

On a vaguely related note, the cynic in me wants to believe that this is all a product of our Prozac-addled Muzak-influenced culture, and that the reduced dynamic range of modern music is simply a reflection of a culture that demands less emotion out of its music. And that that's what we're really railing against.

I have Katz' book, btw (though perhaps not the most recent edition)...if you need me to look something up, just ask.

Right. That is, the measurement techniques we have tend to be good at telling us when we already know something is wrong, but they are really bad at telling us when something is ok. The false positive (and false negative!) rates can be extremely high. This makes most measurement techniques considerably less useful in their predictive power than people realize. Waveform plots are merely the most egregious offenders here.



Say it, brotha. Did you know that the Yes DVD-A of Fragile was brickwalled more heavily than Gaswirt?



I'm arguing here from a purely informational basis. That is, generally (and you of all people are going to understand the exceptions here), SH is known to avoid or reduce compression, and he is more or less frank about when he makes changes like that to his masters. Ergo, hearing from SH something like "I reduced the drum track compression from 4:1 to 2:1" is about as conclusive an example of a dynamic range increase as you're going to ever get.

I agree that Katz is arguably more trustworthy from an engineering perspective, but that's not really pertinent to the discussion. That doesn't really help your buying decisions any, except on name recognition alone.

Another example: Betcha didn't know that Peter Aczel is a huge fan of Mapleshade Recordings...

Given that SH.tv seems to be source of the idea of using EAC peak values as an estimator of audio quality, I'm inclined to agree - at least, I'll hear something from people who know what a waveform is.

It is called relativity. They have no comparision. It is easy to be satisfied with eating shit, if you haven't ever tasted anything better. They have no reference! Their "rating" is literarily meaningless. They enjoy it - compared to what? What? More of the same?

Common people aren't capable of making competent and meaningful ratings - they just do, feel and think as they are told to do. They are believers. This is not a rant with the purpose of criticizing those people and requesting a change. No. Those kind of people have always been like that and will always be like that, because they want to be like that. Its comfortable and seemingly riskfree. What i am saying is that the ratings of those people dont matter. They are irrelevant, because they choosed so. What matters are the ratings of people different to those. The mainstream does not invent and set trends, it follows the trends created by others... its only effect is inertia - or in more friendly words: stability.

- Lyx

"Gainriding your face"?

Yes. The Gastwirt isn't brickwalled at all, is it? It only reaches actual 'peak level' once, in one channel.
What's scary is that the latest CD remaster -- on Rhino, credited to Inglot & Hersch -- is even MORE smashed than the DVD-A.

Anyway, I get more jollies from comparing frequency plots these days, than waveforms...the seem to 'tell' me more about what I'm hearing (prolly because as humans we're so sensitive to EQ changes in the midrange)

Check it out. DVD-A vs Gastwirt:






Hoffmans' 'catalog' is relatively small, and largely out of print, so his impact on buying decisions isn't going to be that great...except for rabid audiophiles willing to shell out $100 for a Hoffman 'Aqualung' CD. And Hoffman's information about various releases has been known to, um, evolve over time...I'd stick with Katz for information if possible. (It's interesting too that there are some Hoffman CD remasterings that are clipped.)




Not surprised. Aczel's certainly an audiophile in the true sense of the word. He doesn't care, ultimately, how the subjectively 'absolute sound' is achieved, as much as he just wants to hear it. He doesn't want to be bombarded with dubious causal claims about it, though. Hence his reference to 'analog druids' and "I have shut my eyes on occasion and could easily pretend that I was there. Is it because of “no mixing board, filtering, compression, equalization, noise reduction, multitracking or overdubbing,” as it says in the blurb? Maybe so, maybe not, but the sound speaks for itself."




Oh, I don't doubt you'll hear lots of things.

First of all, check out Bob Katz's comment (and my reply). BAM! As usual, he lays down the law: his vinyl masters do not include the limiting that exists on his CD masters. I really like his idea of peak-to-loudness measurement too.

Ah, yes. That Mona Lisa smiley-face of an eq is not news to me. When I first ripped it, I honestly did think I could hear a lot more detail in the DVD-A version, but after I level-matched everything, the differences are honestly pretty slight. Methinks there may have been some remixing involved - explaining the large channel imbalances at high frequencies, suggesting some creative placement of percussion in the stereo mix.

They would have had to go back to the multitracks anyway for the surround mix, so I'm imagining that they did a brand new downmix for the stereo version to match the 5.1?

Right. I certainly trust Katz more than SH on any matter of audio engineering. But like I said.... I'm not looking to mastering engineers for general information about sound quality or beliefs or whatnot, I'm looking for knowledge as to exactly what they did with their records. And for some records (but perhaps an extremely small number), SH has fairly comprehensive info out there on what was done with each mastering project, and that information has been both fairly consistent over time and matches user listening experience.

Fortunately, now that Bob is on the record saying that he sources his vinyl masters without added loudness maximizers, I think this particular issue is moot.

No remixing. That large imbalance -- about 6dB at max -- can be created without it. Remember, this graph doesn't compare channel to channel of the same mix directly -- it's comparing each channel to its counterpart on the Gastwirst version.

That's important to keep in mind. What I showed isn't a direct EQ plot -- it is a plot of *difference* between the DVD-A and an arbitrary reference mastering (Gastwirt's). And note too that by that criterion, only one channel is 'smiley' compared to the same channel of the Gastwirt; the other is 'frowny' in the treble region (a half-frown?)

Also: imagine, for example, the same sort of graph where the 'reference' CD was mastered with muddy highs and inadequate bass compared to the original tapes -- a 'flat' remastered CD from the original tapes would look very 'smiley' in a difference comparison to the reference CD. Yet it wouldn't be 'smiley' compared to the original masters.

This pedantic episode brought to you by me, to show that without knowing what's on the master, and without accounting for what's being measured, it's possible to jump to speculative conclusions.

Btw, here's successive waveform views of ripped 'Roundabout' remasters -- please don't punch me.

Gastwirt CD


DVD-A stereo track


Rhino CD









No, that's rarely done. The stereo version here, as is usual, is just the original two-track mix, remastered. I wouldn't bother comparing two different MIXES this way, though I suppose it too could be informative.

You mean, perhaps, a...




I've got some handrolled code which sums the spectral content of two different tracks and divides the two together. So again, these graphs are not news to me.

Right - a bunch of different things could cause this. I just figured that the 5.1 mix added an extra layer of plausibility. In fact, at one point I listened to the DVD-A in my hires player over headphones and honestly wondered if there even was a stereo mix on the disc - I might have wired the 2 channel out wrong and got 2 channels of the 5.1 mix by accident. That may have confused my perception of exactly what is on the 2-channel mix.

Regardless, I'm not sure we have concrete evidence one way or another as to what's going on here.

I promise I won't gainride you... as long as you also post clips from "Five Per Cent for Nothing", which, as I recall, was one of the clearer instances of limiting on the DVD-A.

How do you know this?

And yes, this is all horrifically off topic

d'oh!




For Fragile , I know it because I know that album like the back of my hand (I'm old enough to remember when "Roundabout" was a hit..on AM radio). True for many other hi-rez discs I own too. It's hard to do a remix that is EXACTLY faithful to the original, in terms of getting all the parts in there. The 5.1 channel remix of "South Side of the Sky', for example, has a glaring omission of a bass swell that's intact in the two-channel version.

Elsewhere, because many of these releases date from when ICE magazine was still around, we got 'from the horse's mouth' reports from the remixers, and a remix two-track would have been touted as a news or selling point, as it is in every medium I've ever seen, and I kept track of these things. In fact offhand, I can't think of any DVD-As or SACDs that feature remixed (not downmixed) dedicated 2-track versions, aside from the controversial Genesis set. And if the 'remix' is really the downmix of the 5.1 generated on the fly, that's evident too, on the few discs where that's the case , e.g. ELP Brain Salad Surgery, Natalie Merchant 'Waterlily', by the absence of a selectable 2-channel DVD-A mix in the directories (nothing 2-channel in the AOB directory either). You only get two-channel as a downmix. Believe me, this pissed me off when I bought that ELP disc way back when, because the packaging was quite misleading in that regard. It was later revealed that there was no dedicated 2-channel transfer on that one because the original 2-channel masters could not be found in time. Warner pulled this trick on a few of its early DVD-A, but quickly began including real remastered 2-channel tracks.

Ah, yes. That firsthand knowledge actually dovetails pretty well with my thinking that knowing mastering decisions from the horse's mouth (the mastering engineer) is the most trustworthy method of comparing masterings (besides listening to it yourself). Of course, said engineer can lie, but you've got bigger problems if that's happening.

Remixing the two-channel would make the production even more costly. Really, it was never a big part of the DVD-A /SACD push to have remixed two-tracks; the releases were usually touted as including the bestest-ever remaster of your favorite old album along with the shiny new surround mix (though sometimes Sony didn't even give you THAT). As best I know, every remixed two-track remaster that's on them is also on a CD release as well (Miles Davis, Brubeck, Genesis), I can't think of any that were made JUST for hi-rez.

Here's a list someone posted on HA of some DVD-As that only present downmixes when you select 2-channel. Note that a lot of them come from notorious cheapo disc producer Silverline:

http://www.hydrogenaudio.org/forums/index....st&p=554804

There are plenty of people my age (mid 20s) and older who pretty much don't notice a thing when they listen to modern masterings. Lots of people listen to both their old CDs and their new CDs, and besides the large volume difference, and a reduced reliance on gated reverb, they do not notice much production difference between the two.

Put another way: if what you are saying is true, Norah Jones would not have a career.



Shut up, old man.

SRSLY: "the music kids are listening to nowdays is too loud and too harsh" has been a complaint since, literally, the 1930s - ever since the advent of amplified microphones and dynamic range compression.

If this can only be justified on relativity and elitism, it's never going to punch the mainstream. What, are we going to pursue the Scientologist strategem, and get all sorts of celebrities to complain about how bad CDs sound nowadays?



Hey, um, we couldn't get a mod to split the DVD-A thread off, could we?

I'm simply saying that the "opinion" of the mainstream is just a copy of someone elses opinion. If you get enough hype going on, so that media-outlets tell the mainstream about the problem, it will suddenly as by magic notice it. But: The mainstream on its own, wont complain about that on its own - it does not create, it imitates. It has no own opinion and doesn't honestly want one.

Are you really believing in the "common (non-)sense", "(un-)sensivity" and "(non-)self-confidence" of average joe? Does your average joe seem like someone who notices something unpopular on his own, and then starts to make unusual demands?

Thats how it is currently, regardless of if you like that or not. If you want your "strategy" to work, it needs to include that aspect too. Else you're building on wishful-thinking.

- Lyx

P.S.:Here's a different example. We are compressing the night sky. Yes, we are. By outputting vast amounts of light into the sky, we in most urbanized countries have made almost the entire sky disappear. Only a low amount of handful of stars are still visible. Dozens of sky objects, which in the past were something normal and well known, are now unknown. This is something, which you CAN directly show another person. It's an issue which - similiar to in this community - is decried by lots of enthusiasts. Does your average joe care? Does he even consciously look at above anymore? Do you think the kids born in the last 15 years even have a sufficient comparision anymore? If you tell them about various sky objects, they react as if you're talking about aliens. However, asume the media would create a new nightsky-hype, thus suddenly making average joe be interested in it again. So all those buy googles and stuff - and one of the first enemies they will get to know - the biggest problem nowadays for skygazers - will be light pollution. And suddenly, there would be popular interest in fixing that (there are simple ways to fix it, and it even saves cash). But do you think anything like that will happen out of average joe by himself? Why would someone, who in the past never cared about the topic, suddenly be interested in it, by pure coincidence at the same time as the media report about it?

*de-lurk*


You might as well be talking about city kids in 1930s Britain. When they were evacuated in 1939, many of them had never seen the countryside before. Didn't know what a cow was, never mind that milk came from it.

A lot of them, being from poor backgrounds, found that the beds hurriedly made up for them were vastly more comfortable than what they'd had at home.

I'm fairly sure that the country skies were clearer than the city ones then too - but for a different reason. Smog.

The extremely brief moment of actual clipping isn't the main problem. The major part of the audio vandalism is the extreme levels of compression that were applied before the mastering engineer finally had to resort to allowing a bit of clipping to squeeze that last little bit of loudness out.

If that 1000-sample long rim-shot has been pulled down by 9dB, the fact that the initial 10 or so samples have also been clipped is just a pimple on a boil.

That is a fantastic example.

Edit: I'm looking at your blog post Axon. In that big clipped peak that you show the screenshot of, it seems to me as though the clipping in the vinyl master ends earlier than in the CD version. Do you have an explanation for that? The master looks similar to me, but not quite identical...

The waveform on the vinyl trace has been differentiated by DC blocking capacitors or high-pass filtering at some stage. This will have definitely happened in the magnetic preamp on playback, and I guess that the same will have applied during the cutting process due to the application of a high-pass filter somewhere in the signal chain. The output of a magnetic cartridge is also proportional to rate of change(ish). In short, vinyl doesn't go down to DC.

The effect should be negligible within the normal audio passband with the possible exception of very low frequencies approximating a square-wave unless some bleeding eejit has allowed the waveform to clip, at which point the signal is temporarily stuck at one extreme or the other and becomes a short-term DC level which will be reproduced as an exponential decay towards zero.

The relatively rapid rate of change at the leading edge of this decay adds harmonic distortion several orders of magnitude higher than would have normally occurred had the clipping not taken place. You will also see the same differentiation on your headphone or loudspeaker outputs regardless of whether the source is vinyl or digital unless the entire system is DC coupled from source to output which is probably unlikely.

This is yet another fine example of why a recorded waveform should never be allowed to clip if it's in any way avoidable.

Cheers, Slipstreem.

Bah. I was just wondering about the same thing.

I'm playing around with a new technique for clip detection (well, it's new to me anyway - I hope to post the basic idea soon), and I'm pretty consistently seeing that, for this album, clipping starts occurring about half a millisecond later on the vinyl than on the CD, and it stops about half a millisecond earlier.

The only explanation I can offer is that clipping is occurring on the vinyl at a different, higher level than on the CD. Mistracking, or resonances in the vinyl playback system, would certainly not cause behavior like this. I do have some like HF resonances with my cart, but that doesn't explain why the clipping both starts later and stops sooner.

That, if true, would considerably weaken my point that Mirrored is sourced from exactly the same master as the CD. But the more fundamental point - that vinyl isn't necessarily free of clipping - is still upheld.

Cliveb's Wave Repair has a very good user-configurable clip detector. It can be set to detect clips of arbitrary consecutive sample length, at an arbitrary level at or below 0dB (and the level can be a range)

http://www.waverepair.com

I made a new thread for it --

http://www.hydrogenaudio.org/forums/index....showtopic=65859

I don't have that. I do have a reference for the audibility of gaps in noise, which (at the limit) is what clipping of over compressed pop music comes pretty close to...

Penner, M. J. (1977).
Detection of temporal gaps in noise as a measure of the decay of auditory sensation.
Journal of the Acoustical Society of America, vol. 61, no. 2, Feb., pp. 552-557.

...I mentioned that because the threshold is quite high - it's 2-3ms. If you look at the gap in an audio editor, you would never believe it was inaudible, yet it is.

That experiment is far simpler than clipping though - because the surrounding audio is spectrally white and completely random. Most CDs aren't like that! With clipping, there are audible effects that make much shorter durations audible. TBH, I think discussing the duration as if it has some kind of correlation with audibility is silly - clearly you need a full psychoacoustic model to judge whether the clipping is audible or not, as you have to take account of gap detection, harmonic distortion, and level change - all wrt known psychoacoustic thresholds. This isn't a trivial task, but it's not impossible.

Cheers,
David.

I think this is a great thread. I don't have time to reply properly, but...

I think lyx's description of the world is spot on...

http://www.hydrogenaudio.org/forums/index....st&p=587368
and
http://www.hydrogenaudio.org/forums/index....st&p=587425

...and of course the commercial world will always be driven this way. The tragedy* is that much of the music that's damaged in the process will have value beyond it's time, and beyond it's target audience - this value is dramatically diminished if all we have are clipressed versions.

Of course clipression is just part of today's sound. Just like, in the 1960s, 4th generation dubs played back on a Dansette record player were part of that era's sound. However, lots of music from the 1960s has transcended that, and is still listened to today. However, the music that only exists in that form fairs worse than the music where a 4-track master tape still exists, and the recording can sound decent on CD.

I visited a friend the other day, and he'd just spent some serious money on a new stereo. He was complaining that he couldn't listen to half of his CDs any more! He loved lots of indie music, but to his surprise, even CDs from "rich" bands (e.g. Oasis) sounded terrible. I think, as the clipression generation grows up, and starts to listen to "their" music more on decent stereos than on their mobile phone's built-in "speaker" there will be a commercial imperative to re-master these recordings.

However, just as with the 1960s, some of the masters won't be there to re-master, and some of the artists won't allow it to happen.


I think any clipping should be avoided (unless it's for artist purposes - and then not normally on the whole mix!) because, as someone else has said, it's an undesirable process.

How bad the clipping and overcompression sounds is purely subjective - as we rarely have a "good" and clipressed version to compare, it's not like we can ABX or use a standard psychoacoustic model to detect the difference - we just have to listen to what we have, and say if it sounds pleasing to us.

Axon is correct in that the pictures don't correlate perfectly with what we hear - but it would be nice for both the pictures and my ears to tell me that there are no problems of this kind at all!


Cheers,
David.

P.S. *(the almost criminal thing is that many public institutions, which are supposedly there to guard against the almost all consuming power of what lyx describes, are now complicit with it, or are even encouraging it. Will those who care make them change direction, or simply tear down such institutions because they believe they have become worthless? That's a bit deep for HA!).

I think that's why ReplayGain (or something like it) should be present in every consumer playback device (or as near to it as makes no odds), and turned on by default. And when it's turned off, it should have a fixed 20dB attenuator, to stop "ReplayGain off" meaning "louder" to Joe Sixpack.

Then we'll have an end to the Loudness War, and instead we might get a return to quality metrics.

Apple's already half-way there, but I'm not sure they fully understand the problem, and they're not "every consumer device".

Apple is indeed - intentionally or not - currently the most powerful force in making the loudness war pointless. However, it is IMO indeed only halfway there - because in addition to something like RG (soundcheck) it also needs to offer *dynamics compression*. It needs to put the compressor-choice completely into the hands of the consumer.

WTF, why's that, isn't compression == bad, and noncompression == good? Well, tell that anyone who wants to listen to dynamic content in locations with really high noisefloors. Those are situations which are intuitively associated with the iPod, and therefore - from a music producer POV - neutralize the soundcheck effect. Right now, there is still a "point" in compressing music regarding the iPod, which is the use in high-noisefloor environments. If you build a compressor right into the player, that point vanishes as well and there is no argument left anymore for compressing music for ipods (from a music production perspective).

Also, i think a good default amping for no-RG mode would be -10dB.


In such scenarios, there is a third option which is rarely noticed: make the existing institution irrelevant by circumventing it with a self-created alternative.

Switchable compressors are already built into some consumer equipment - I've seen it on a 1990s car radio (as a "loud" switch) and recent home theatre receivers (as a "night mode" switch). I agree, it would not be difficult for Apple to include one in iTunes and the various iPods.

Actually, I should check to make sure "Sound Check" doesn't already include one. That's always a possibility. I'm also not sure what "Sound Enhancer" in iTunes does.

IMO, however, most modern music is naturally not so dynamic as to impede walkabout listening. There are exceptions, of course, and a switchable compressor would definitely help with classical and other dynamic music.

I don't think -10dB is enough to prevent an ultra-hot master from sounding louder than if it were RG'd. Perhaps -15dB would work though. Some ultra-hot masters are showing up near -14dB and certainly over -13dB. We do need to stop people from thinking RG is a "lame" "quiet" button. I don't think the preamp boost with RG on is a good idea, but a preamp cut with it off is.

And you think that people will switch RG off, because SOME songs sound 4db louder with RG off?

Have you investigated the downsides (cost) of generally reducing the signal significantly? Have you tried to asume the POV of someone who prefers RG off, and make that option feasible for him, or are you only focussed on "making non-RG look bad"? If you asume a totalitarian POV, you can as well force RG, and remove the "off"-option.... no use for a useless option. If you include that option, you need to make it useful and feasible - else there's no point in including it.

P.S.: You might be interested in this:
http://www.hydrogenaudio.org/forums/index....mp;#entry573516

Well, Sound Check isn't a compressor, just a level shifter. I checked this on both my iPhone and my MBP. So it's basically ReplayGain with a pretty face - which is no bad thing.

I'm still not sure what Sound Enhancer does, but it isn't compressing either. I've simply turned it off again. I think it might have a short-term expander and/or a stereo expander, but I really can't be bothered poking at it.

The above determined using a 17.5 minute version of Blue Room, which has a long-term dynamic range of about 40dB. It would have been very easy to see compression used on that.

Yes. That's what the Loudness War is all about anyway - they wouldn't do it if it didn't sell.

One of the interesting things about RG, as it happens, is that it allows the mastering engineer to pass on his level setting. So we might see digitally-distributed tracks coming straight from the shop with RG tags on them. This is both good and bad:

- Responsible engineers will set a sensible level, allowing plenty of dynamics, and match their RG tag to it. This would be excellent news for audiophiles.

- Mediocre engineers will keep doing what they usually do, probably without RG - or they'll use a generic RG tagger after the fact. This is okay.

- Bad engineers will game the system to produce tracks that are still "hot" on an RG-compliant device, by setting the RG to +0.0 (or at least to a higher numeric value than justified). This would be catastrophic.

So it is clearly necessary to define proper standards for this kind of thing. Standards *do* work - notice how consistent movie soundtrack recording is, and how DRM-on-CD has mostly failed to catch on, since Philips forbade DRM-CDs from using the CDDA trademark?

The question is, who gets to make the standards and enforce the trademarks?

Wait, wait - now your are confused. First you were talking about "reducing amping", so that SOME LISTENERS don't turn RG off for the sake of loudness. Now you are talking about "reducing amping", so that RECORD PRODUCERS dont overcompress the source material.

Make up your mind. Which of the two is the DIRECT purpose for reducing amping when RG is set to off? If you asume that both are the same, then think twice.

- Lyx

P.S.: Also, dont simply asume that record labels act logically. Decision makers in the industry are primarily driven by beliefs, greed and fear. Each of those isn't necessarily identical to actual profits. (*cough* DRM *cough*)

Isn't a more accurate analogy that we are reducing the signal to noise ratio of the sky by allowing light pollution?
We have raised the noise floor to the point where much of the signal is lost.

If we were compressing the sky then all the stars would be approaching the same brightness.

The sun, BTW, appears to be clipping.

Bump for an updated version incorporating everybody's feedback:

http://audiamorous.blogspot.com/2008/09/wa...ed-harmful.html