What is the least compressed signal?

If "compression" is defined as adjusting the amplitude of all waveforms so that their amplitudes are all as equal as possible across the spectrum,

Without RIAA, you'd loose 20-40dB of dynamic range.

You have it backwards.


Best,
E

FTR: I did not quibble. I anti-quibbled.

Without even going into room acoustics and vibration isolation and rf, the primary culprits are the stray scattered laser light getting into the photodetector and the vibration, wobbling and fluttering of the disc itself. Both of those problems together I estimate to constrain and limit full dynamic range by at least 3 to 6 dB, probably even more.

Hahahahhahaah

What is dynamic compression if it's not equalizing all of the wave forms to have a uniform amplitude? That's EXACTLY what RIAA equalization is designed to undo.

Hi kosst,
Sorry but the RIAA curve does not alter dynamic range, nor does it attempt to reduce all wave forms to a uniform amplitude.

Look at it this way. If I turn the treble down on my amp, I have not altered the dynamic range, at all. The tweeter now just plays 4 dB softer than it did before, but the range, the delta between softest and loudest, remains up to the music. 

Best,

Erik

Hi @geoffkait

For some odd reason I haven't the desire to quibble with you over the meaning of "early." 

Carver showed early on that some CD's were compressed both in dynamic range as well as reduced channel separation. Of course, individual CD's varied, and the loudness wars continued even then.


Best,
E

Vinyl by itself is insanely compressed which is why you need a pre-amp with insane slopes to re-equalize it into something that sounds like music

While we can argue about the dynamic range and noise levels of CD vs. vinyl, I’m afraid this is not supporting evidence. I am afraid Kosst is conflating compression with equalization.

Dolby or dbx both have analog compression methods. The RIAA curve is just an EQ to deal with noise and velocity driven transducers.


As has been noted before, early CDs were severely compressed compared to their vinyl counterparts, so the mastering and the tech both impose the limits we hear.

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.

Here, read this:
https://grimesaudio.wordpress.com/2018/10/23/the-loudness-wars-a-brief-history/

Also google "loudness wars" for more, including the BBC's samples of Thriller.