What is the least compressed signal?

" CDs as a rule are not compressed at all. They present the full Red book audio signal in non comprsssed format.
I am sure I added a lot of confusion, sorry about that . . ."

That is correct but it is confusing. The data on the CD is not compressed as such but many if not most CDs in the last 10 years or so are woefully compressed in terms of dynamic range.

Geoff is correct, the site he linked to is very helpful in terms of buying music and as mentioned the DR can vary widely between CD, LP and downloadable files of the same music released at the same time.

For a new audiophile one of the things that can tip you off in terms of dynamic range compression is the volume.

Put in Mark Knopfler's well produced Tracker CD. Set the volume at a moderate comfortable level. Listen to it. Then, pop it out and put in Alabama Shakes Boys and Girls CD. Do not change the volume....but hold your ears....the Alabama Shakes CD is horribly compressed and will be much louder. And even at a lower volume on your system it will make your ears tired. Subtlety is lost. And even a well written, well played album like Boys and Girls is ruined by terrible production.

And yes, as @wolf_garcia  said, judicious use of compression is a necessity and nothing new in the recording world. Done properly it enhances the music. Done with a club and a hammer it ruins the music.

A live concert.

Sorry to be disagreeable the data on the CD is compressed. That’s why they sound compressed. That’s what compression means, that it’s dynamic range is compressed, squeezed down, suffocated, strangled, flatlined.

Sorry to be disagreeable the data on the CD is compressed.

You aren't disagreeable, just generally wrong.


There is no data compression on the audio data for Redbook CDs. HDCD is, of course, an exception.


Dynamic range compression and level shifting is up to the engineer who makes the master. This varies a great deal depending on genre and era.  In addition, plenty of evidence of reduced L to R separation and significantly different EQ being used, not just from medium to medium but even from release to release on the same medium.


Also, while I dislike the loudness wars, the opposite, excessive dynamic range is also a bad thing. Like watching a movie when you have to turn up the volume to hear the dialogue, but then the action scenes are deafening.


Some compression is probably a good thing, and brings out more details and more room ambiance than otherwise, so treating any medium as absolutely more or less compressed ignores all of the complexities that occur when it lands on your stereo.

If the engineer compresses the data what do you think appears on the CD? Three guesses. The first two don’t count. There is no evidence of ANY advantage to overly aggressive dynamic range compression other than being able to make the CD louder. There is no correlation between dynamic range and resolution. Dynamic range is simply a ratio. There is no resolution function or ambience function in dynamic range. That’s probably what the recording industry would have you believe. That’s what the whole debate is about. That’s why they call it the Loudness Wars. If there are no dynamics it’s not music. Digital is the new wimpy.