New CD discs-Older discs Volume difference?

[JJkizak]

Noticed my older CD discs have about 10 db less volume than the new discs. Are they using some new technique to juice up the new ones?

JJK

[artto]

Many of the early CD releases were mastered from copies of the analog master tapes that were used to produce vinyl LP. These tapes had levels that varied according to their dynamic range relative to what they could "fit" onto an LP, the details of which were done "on-the-fly", under a microscope during the final stage of "mastering". In the beginning they didn't seem to take too much care in making the transfer of the analog tapes to the digital format. It was also common for the mixing and/or mastering engineer to leave some "headroom" to reduce the possibility of clipping during the final mastering stage. It was not as "exact" of a sience back then. It was common to leave 10-12dB of headroom to allow for the lag of the VU meter ballistics.

Nowadays, as the final step in the CD mastering process, most CD data are "normalized". The "normalization" process scans the entire CD data, finds the highest peak levels, and then "normalize" the data to maximize its volume, based on the waveform's highest peak, without clipping the data during playback.

[Thoriated_Tiger]

There's also variations between genres of music, it'd seem.

Most classical and jazz CDs I have, I give it six clicks on my SP6A's knob, for peaks to ~90 or so. (each click is about 2db)

With most pop / rock, three or four clicks will net you peaks to 90. These are recorded "hot".

The few pop/rocks that act like the classical ones are all from weirdos: Pink Floyd, ELP, ELO, etc.

[franczyk]

It is also a trend for recordings to be louder... At least for newer music, the recording engineers tend to turn the volume up and don't worry about how much of the transients and dynamics they cut off.

Its a nasty trend that I hope starts to fade someday.

[DrWho]

In addition to the things Artto mentioned, new recordings are implementing more advanced compression techniques to increase the apparent loudness. Note that loudness is not the same as SPL. A signal at 0dB on the CD is going to be the same SPL for all CDs. However, you can make it seem louder by various EQ/compression combinations and tricks. The reason for all this crap is that it's purely marketing. To the human ear, louder generally sounds better...so when a song sounds louder than the rest, the theory is that the song will also sound better than the rest. For the mid-fi market this is a great tool and it will probably never go away considering that's where 90% of the money is made. In the hi-fi market, these "loudness" tricks just ruin the realism and cause intense listening fatigue.

[Rivendell61]

As I understand it there are several reasons, including:

1) Early CD mastering was overly concerned with avoiding overload and so kept levels low--often too low, as engineers now understand.

There was a recent thread on Hoffmans Forum about this, and the explicit instructions with the early Sony CD recorder to keep vols low--and a mark at

-10db for Max vol. Thus quiet early MoFi's, etc.

They soon learned was not optimal for the sonics....

(according to that thread Steve Hoffman does not use digital normalization--but manually sets max db for zero peaks.)

2) Recent trends (esp in pop) are toward louder/compresed cds.

There is a very good article (a bit dated) on this here:

http://www.prorec.com/prorec/articles.nsf/files/8A133F52D0FD71AB86256C2E005DAF1C

--with graphical examples of the progessive ruination of Rush CDs via louder/clipped cds.

Mark

edit: DrWho explained 2) better--I was typing as he posted.....

[Duke Spinner]

listen to the "Doctor"

especially in hip-hop/ rap ...

the producers are all in a volume race

the looser here ...Dynamics

compressed right out ....

[JJkizak]

Thanks Guys. I was just wondering what was going on.

JJK

[khorn58]

Its not the mix enginers fault for the modern over compresesed pop sound ,its the Mastering enginerar who compresses the sh^t out of it so the lastes song will play louder on the radio than the last one.it all about money to be made no improments in sound.

soon they will be mastering them to sound good on mps3 over full files songs. It is like the 8 track all over again full the masses into thingin they are getting somthing better.

[colterphoto1]

Good explanations all, esp liked Arttos and the good Dr's posts.

It's a shame that CD technology promised all this 'dynamic range' which has been lost due to heavy handed recording engineers. Put a stop to this, will ya Doc?

Michael

[dodger]

It's also so that the listener will catch a radio station right away.

Noted earlier, additionally this helps your scan button pick a signal up. It keeps that signal as close to maximum all the time.

Two other '60 s & '70s bringbacks I've heard as of late is speeding up a song so a station can claim more songs per hour and the speeding and leaving no gaps in commercials. More words per 30 second spot and again, if you hit scan, no open air to miss the station.

Plus Tunes are now on mass chips, no CDs on a number of stations. Accurate enough so that they be recorded and and the mandatory station identification plus "quarter past the hour, etc." can be added.

dodger