To what degree DR reflects SQ?

[firedog]

The DR by itself means nothing. DR reflects the difference between the loudest and softest parts of the music. Lot of music doesn't have very much volume dynamics, so it will have a low DR. Doesn't mean it wasn't recorded/mastered well.

What you don't want is music that was originally made with a relatively high DR, and then heavily compressed. That doesn't sound good. 

[firedog]

Here's what the Roon Knowledge base says about computing dynamic range:

Quote

 

How is Dynamic Range computed?

As with Volume Leveling Roon's dynamic range calculation is done based on R128 standards. In technical terms, Roon's "Dynamic Range" is the same as R128's "Loudness Range".

That there are older methods of computing Dynamic range out there--most commonly by measuring the "Crest Factor". 

Crest Factor measurements reflect the difference between the average volume and the peak volume--so they are easily swayed by periods of silence or near-silence (which distorts the average), and by short-duration peaks--which may not represent the volume of the loudest parts of the track accurately.

The R128 method is more resillient. It begins by computing the statistical distribution of loudness values present at different points in the track, ignoring periods of silence. The computed dynamic range represents the difference between the 10th percentile and the 95th percentile of that distribution. In other words, the "top" of the range is the volume level that 95% of the track sits below, and the "bottom" is the volume level that 10% of the track sits above.

Though both methods portray roughly the same information, Crest Factor values aren't directly comparable to values produced using the R128 method

 

The R128 method makes more sense to me, but I find in practice that the DR number more accurately reflects what I hear.