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View Full Version : How far can a CD be "hypercompressed"?



Mark Lanctot
2006-11-18, 11:02
There's been a lot of reference to increasing CD hypercompression. This is really evident when you use ReplayGain and look at the RG values of CDs over the years.

I believe the mid-80s were the peak of CD technology. This is when I believe the format was most mature - they had worked out the initial bugs and were getting comfortable with the technology, plus CD players were expensive back then so it was a luxury item. RG values made from CDs in that period are very slightly negative, -2 or -3 dB, or even positive, +0.5 dB. As an example, look at INXS - Kick. Few albums sound that good these days. (I'm not necessarily talking about content, I'm talking about clarity, dynamic range, volume level, etc.)

Since then, RG values climb more and more negative. -5, -6 dB through the early to mid-90s, -7, -8 dB by the end of the '90s.

Now RG values are routinely -10, -11 dB and clipping is evident in many tracks.

What I have noticed is that this value seems to have stabilized at about -11.5 dB over the past 3 years or so. I have not seen any RG value of -12 dB or lower.

Does this mean:

1. This is some sort of physical stop, CDs cannot be mastered louder than 83 + 11.5 dB = 94.5 dB?

2. Recording studios have settled on a "loudness"?

3. This is where things currently sit, it will be getting louder still in years to come?

Unfortunately I suspect (3) but it's strange that the peak seems to be -11.5 dB, I see that very often in new CDs. Never -12 dB.

Craig
2006-11-18, 13:41
There is a classic article about the subject at
http://www.prorec.com/prorec/articles.nsf/articles/8A133F52D0FD71AB86256C2E005DAF1C but the site seems to be down at then mo.

In defence of the recording studios, this is generally forced on the mastering engineers by the record companies. They don't generally leave the studio sounding like that.

Craig

Mark Lanctot
2006-11-18, 13:56
In defence of the recording studios, this is generally forced on the mastering engineers by the record companies. They don't generally leave the studio sounding like that.

So somewhere in the hopefully not-too-distant future when we realize what a crime this is to do to music, we can have properly-recorded music off the original studio tapes?

That would be good, because if the masters are clipped, that data is gone forever.

Not that a whole helluva lot of music made today will be worthy of being listened to 20 years from now, but some of it will be.

Dougal
2006-11-18, 14:43
Yep, itís really disheartening removing the cellophane from a shiny new cd, pop it in machine, reach for the volume and it makes no difference, there is just nothing there!
I think this is something that has to be laid at the door of the big four labels, the independents seem to take much more pride with their art.
Doug.

Craig
2006-11-18, 23:14
Yep, itís really disheartening removing the cellophane from a shiny new cd, pop it in machine, reach for the volume and it makes no difference, there is just nothing there!
I think this is something that has to be laid at the door of the big four labels, the independents seem to take much more pride with their art.
Doug.

I think that is the point, to the artists and the recording engineers it is music/art to the record companies its a product.

Craig

Craig
2006-11-18, 23:17
So somewhere in the hopefully not-too-distant future when we realize what a crime this is to do to music, we can have properly-recorded music off the original studio tapes?

That would be good, because if the masters are clipped, that data is gone forever.

Not that a whole helluva lot of music made today will be worthy of being listened to 20 years from now, but some of it will be.

That's still possible, The music leaves the recording studio as a 2 track 'master' but then goes to be 'mastered' that's when most of the compression is applied, so assuming they can get their hands on the studio 'master' then it can be 'remastered'

Craig

tommyz
2006-11-21, 08:19
Bob Katz also has something to say about the loudness race:

http://www.digido.com/modules.php?name=Content&pa=showpage&pid=45



ciao, TommyZ

Eric Seaberg
2006-12-03, 10:11
I've been in the recording biz for over 35 years, and have had several threads with Mr. Katz (his book is worth reading by ANYONE that listens to music).

It all comes down to 'air-play' and everyone wants their music to sound as loud as the previous track. They forget that ALL radio stations have their own processing in-front of the transmitter that takes care of this.

In fact, in Bob's book, they ran a comparison test taking the same piece of music mastered by 6 different mastering engineers. They showed the waveform display of each after mastering, then ran it through an Orban Optimod (the typical processor used by every radio station). The original waveforms all had varying dynamics based on the way the engineer heard it, from lots of dynamic range to almost none.

By the time the 6 files were run through the Optimod they all looked IDENTICAL!! Actually, the ones with less dynamic range sounded WORSE after processing. This is making a lot of mastering engineers consider, at least, keeping dynamics in the music. Of course, some stuff doesn't have any dynamics anyway, so it's a moot point.

It really made me rethink the way I work!!

There is talk of some mastering facilities actually doing separate 'versions' of a CD... one for air-play and one for the consumer. As more and more music listeners/buyers complain about the lack of dynamics, more record companies will make a slow change.

By the way, if you ever have looked at the waveform of a typical CD release, the audio is virtually CLIPPED. The distortion makes is sound LOUDER... and that's the whole point, right? (NOT!)

Havoc
2006-12-03, 12:24
Honestly, I don't think airplay is that important anymore. The time there was a radio on everywhere is gone. Most people just lisen to some form of mp3 player these days. Even in the car radio is a minority.

Eric Seaberg
2006-12-03, 20:44
Honestly, I don't think airplay is that important anymore. The time there was a radio on everywhere is gone. Most people just lisen to some form of mp3 player these days. Even in the car radio is a minority.

...and your point is?

Sales has ALWAYS been about airplay... word-of-mouth has to start somewhere. Where else does the 'push' come from?

...not that I'm making a deal about airplay as much as WHY the dynamic content has turned to 'none' in the last 10+ years.