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Loudness and Accelerate - An Essay

Monday, April 14, 2008

I had asked by good friend Drew Crumbaugh to write an article about loudness and Accelerate and he came back with a very detailed sketch that even the sound novice would be able to understand. 

By Drew Crumbaugh
Try this fun lil' game, safe for children of all ages.
Grab your Accelerate CD. Then grab your Document CD. Musically similar - angry agitpop, noisy guitars, both albums mooted as Peter's show. For this game, great.
Find your trusty headphones, and play Document. Seek to about 1 minute into Finest Worksong and set the volume to a comfortable level. Keep the volume set there for the entire CD. Have a good listen, drink a beer, do whatever you wish but make sure to listen to the entire album.
Now try this same scenario with Accelerate. Except this time, keep the volume the same as what it was set for with Document. Can't do it, right? It's too loud! But loudness (or rather, perceived loudness) isn't the problem here. So let's modify this game a bit. Keep listening to Accelerate, but this time go back to the first minute of Living Well, and set the volume there to a comfortable level. If this comfortable level for Document was, say, 4, here it would probably be 2 or 1. Listen to the whole album.
Getting a bit tired? Ears feel a bit sore? Whether you recognize it or not, your brain *is* tiring of the relentless pummeling Accelerate delivers. And it's not the actual music's fault - Document, similar style songs, didn't do this to you. Neither does Monster, nor Lifes Rich Pageant.
So what's going on here? And what can be done to fix it?
Before I offer up suggestions, let's try this game again - except this time with the LP version of Accelerate. You will have to take my word for it because most people don't a) have this on vinyl or even b) have a turntable anymore, but playing the same game with LP copies of Accelerate and Document reveals much more satisfactory results. Yeah, there's the vinyl lover's favorite mumbo jumbo about more warmth, more what-have-you with vinyl, but that's not the issue here. The issue is that - all things being equal - mastering music for vinyl is a completely different ballgame than mastering for CD.
Document sounds about the same when you compare vinyl vs CD versions to each other. For our purposes they are the same. Which means a couple things:
    1) Each version was mastered with care - the CD mastered well, and the LP mastered well
    2) Personal choice aside, there's no issue vinyl-vs-CD as to which is the preferable medium to listen from
Accelerate, on the other hand, is an entirely different story. To explain, we have to step back a bit and define some terminology here – namely mastering.
Mastering  - what is this? Mastering can have several meanings – the most basic sense of the term, as applied to music, is the assemblage of multiple tracks into a coherent whole, assembling the running order of the album, smoothing out EQ issues, and just generally prepping the music for release.
The other sense of the term is what we're questioning here. In this sense, mastering is the physical process of preparing the album for manufacture. When you master for CD, you ultimately deliver to the manufacturing house a glass master. For this analogy, think of it as an actual glass of water. The music is the water level in the glass, or, say, the drips on the sides, the drips being volume peaks. The glass itself is the maximum capacity of Music that can be held, volume-wise (and in this sense I do mean volume, as in "damn that's loud" volume).
Think of music as having peaks and valleys. The peaks are the loud bits. The valleys are the quiet bits. When there's room for both, the peaks can look like the tallest mountains on a plain - they look like Mt. Rainier or Mt. Fuji i.e. classic mountains. Using our glass analogy, when the glass is half-full of music, the peaks (drips on the sides) can stretch to the very top of the glass. In this case the perceived volume is, say, 5, when the loudest bits can get occasionally to 10 (the top of the glass). When the plain itself - the overall volume, or perceived volume of the music – is created too high (in this glass analogy, say, at 8) the peaks can only go so high. But if that peak was a drum crack that in any other case would rise up 5 volume notches on the scale to our maximum of 10, with only 2 to rise (from our base level of 8 in the analogy) where does the rest go? Remember, when you raise the perceived volume from our ideal of 5 to 8, you raise *everything*. And in our glass, there's no over-full. It's either partly full or entirely full. And you can't squeeze more water in there without - here we go - compressing the water.
It's the same with music. If you're trying to squeeze more music into a container that can only hold so much, you have to compress it. Think of compressing as squeezing. When you try to shove that last sock into the sock drawer that's near to bursting, you smoosh them together to make them fit.
In that process of smooshing you're pushing down any stray sock fibers that are poking above the surface of the sock. When you compress music to fit into our fixed-maximum-volume glass, you smoosh those peaks down. So what would have been a dynamic peak becomes a mushy peak. Dynamic here means has room to reach it's own maximum from the mean level (our music at perceived volume 5). Mushy means it suddenly lost that headroom to grow 5 notches from the perceived volume to its maxiumum of 10 - it only can grow 2 notches before hitting the ceiling, or being physically chopped off. In this case the peak - which in the mountain in the plain analogy - doesn't look like a peak anymore, it looks like a plateau, or the top of a brick wall. Sharply-angled sides with a flat top. In technical terms, this is a square wave. Square waves are distortion, they have no tone or color or anything we would call "music". We call these flat-topped waves "clipped" as they
look just like you clipped off the peaks with scissors. Clipping is a bad, bad thing in digital music. Clipping means that what *should* be a dynamic peak instead is distortion. That dynamic peak, in the studio it sounded like a rimshot or a guitar bleat or Stipe's "I'm collecting vinyl" etc. On the clipped CD, it's distortion.
What on earth does this have to do with Accelerate?
Remember, our glass can only hold a maximum of 10 volumes - you can't stretch, bend, pull, spindle or mutilate the glass to accommodate more volumes. Back in the late 80s/90s, the average volume of a commercial CD was, say, 4, with the peaks hitting 8-10 with plenty of headroom to do so. Then as the 90s crept on, that average volume crept up and up. Early this decade it was at 6 or 7. Now we're at 8-9 and in some cases 10. And also remember, when you increase the average volume, you increase *everything* except the maximum volume limit itself. Little to no room for those peaks to stretch up to 10. So everything starts to sound like a loud, sameysamey pummeling onslaught of noise with no discernable room to breathe.
Going back to Document, those peaks - from their average volume of 5 – have plenty of room to stretch to 10, and you actually psychoacoustically  *hear* that room. Your brain perceives the depth, the space, the "room" for those peaks. But with Accelerate, we are at an average volume of 8, possibly 9.
Where do those peaks go? Your brain perceives that there oughtta be something there, that there's something trying to squeeze out of the glass, but it can't. Your brain hears that struggle and thinks distortion, it gets tired. It starts perceiving the music as a constant blur - you actually have to *work* to enjoy it - to overcome the brain's tendency to tire. You may not think so or consciously think about it, but it's been proven to be so.
Wikipedia has a *very* good article on this concept - squashing the dynamics in order to make CDs appear as loud as possible, commonly known as the Loudness War.
In addition the following article over at the (sadly) now-defunct stylus online magazine site is another terrific introduction to the concept.
Back to our original comparison - the vinyl vs the CD. What is it about the vinyl that makes this loudness concept irrelevant with vinyl versions.
Essentially, vinyl cannot be cut to similar characteristics as modern CDs due to technical limitations of the vinyl medium. If vinyl were to be pressed to be as loud as, say, the Accelerate CD, you would need a vinyl disc about 3 feet in diameter to accommodate the wide grooves loud sounds require. In addition, the stylus would be physically jumping out of the grooves. Furthermore, vinyl mastering engineers - the guys who actually take the source materials and prepare the vinyl metal mothers, stampers, the things required to actually press the record - often, if not always, use a different source to press the vinyl than the CD mastering guys use. So let's say Warner Brothers decides to issue an album on both vinyl and CD. Let's say this is Accelerate. Warners sends a tape master (or ProTools files,
Or what-have-you) to two different facilities - one for the CD (in this case to Alchemy Soho in London), and one for the vinyl (in this case wherever Stan Ricker, the vinyl mastering guy, works). CD guy John Davis at Alchemy Soho has a history of producing Loudness War-contributing CDs, and as could have been predicted, masters the CD to be extremely dynamic range limited (perceived volume at 8 rather than 5 as described earlier). Vinyl guy Stan Ricker takes his source and makes the vinyl master. Stan Ricker is extremely highly regarded in vinyl circles as one who produces very clean, clear, beautiful-sounding records. No surprise Accelerate on vinyl sounds nice - it's still "loud" in the sense the source material was recorded that way, but not LOUD because it's just not technically possible with vinyl.
So what can you, Joe Listener, do about this?
Not much. You have a choice in choosing to listen to the vinyl version, the CD version or neither. And let's totally disregard iTunes/Amazon/Napster store files - they're typically ripped from the CD.
Typically, you can get away with listening to these Loudness War CDs on bookshelf speakers, boomboxes, etc just fine as those types of systems don't reveal as many flaws as higher-end equipment does. Accelerate even sounds halfway decent on a good stereo, but placed next to the LP - from a  purely dynamic perspective, saying nothing about analog warmth or other blather some vinyl purists use - it's no comparison whatsoever. And shudder to think about listening to the CD on headphones as you quickly tire.
There are some things one can do digitally with the CD in programs such as Adobe Audition or the like, but they're a poor approximation of what should have been done correctly in the first place. I don't recommend doing so unless a) you know what you're doing, i.e. know basic acoustic theory and are familiar with waveforms, and b) you don't mind having something that is in and of itself a distortion of the original recording as digitally
"fixing" clipped/compressed waveforms introduces its own problems/errors/etc.
If you have access to Accelerate on vinyl, and any halfway decent turntable, you can burn your own copy of the vinyl onto CD either via a standalone CD recorder or hooking your stereo up to your computer's sound card. I've done that many a time with various LPs and, done with care, it blows the released CD versions out of the water - especially when the existing CD versions were either mastered poorly or Loudness War victims.
But the best thing to do would be to complain loudly to the record companies and the artists. I can't think of a single mastering engineer who *enjoys* producing crappily-mastered CDs, they do it because they have to feed their children. They do what is asked of them - the record company and/or the band is the client and the engineer must do what the client requests. Any engineer who is asked about it says if left to their druthers, they would produce beautiful-sounding product, but then the band and/or record company will complain that it's not loud enough or sounds too flat compared to the latest-and-greatest flavor-of-the-day. And again, they have to put food on their table themselves... So the cycle continues, wash rinse and repeat.
Hope this wasn't too complicated or confusing to read. It's frustrating when there's music as good as there is on Accelerate and on the most common medium, the most convenient medium - CD - you're not getting it the way it's produced at all.