I agree with everything in Mlsstl’s post just above, except that I would add an important clarification to the following statement:
I can tell you that that 90+ dB dynamic range on a CD is largely unused.
It’s important to distinguish between the dynamic range of the medium and the dynamic range of the music. The dynamic range of the music refers, of course, to the difference in volume between the loudest notes and the softest notes. However the dynamic range of the medium needs to be vastly greater than that, to capture the detail in each of the notes. And therefore much of the 90+ db dynamic range of the CD medium is still necessary even if the music has been compressed to a dynamic range of less than say 10 db.
I also agree, btw, with Mesch’s statement that many home measuring devices are unlikely to be fast enough to fully capture the amplitude of very brief dynamic peaks. Although my Radio Shack **digital** SPL meter, model 33-2055, set for fast response and for "C" weighting, seems to do a pretty good job. I say that based on comparisons between measurements I’ve made with it of some classical recordings having particularly wide dynamic range, and waveform observations I’ve made of those same recordings on a computer, using a professional audio editing program.
BTW, as a point of interest there are at least two classical recordings in my collection that I’ve found to have a dynamic range that by means of those waveform observations I’ve determined to have a dynamic range of approximately 55 db, which is simply amazing! Those are the Telarc recording of Stravinsky’s "Firebird Suite," Robert Shaw conducting the Atlanta Symphony, and the Sheffield Lab recording of Prokofiev’s "Romeo and Juliet," Erich Leinsdorf conducting the LA Philharmonic. Both were apparently recorded in 1978.
Correspondingly, when I listen to those recordings at an average level just in the mid-70s at my listening position, with the softest notes in the vicinity of 50 db, brief dynamic peaks reach approximately 105 db at my listening position!
Best regards,
-- Al