In our quest for perfection we like to have the maximum dynamic range, lowest THD and noise. But, how much matters?
We've discussed before that the impacts of low distortion begin to evaporate below 1/10th of a percent and that the methods used to lower distortion and noise beyond that point are often times more impactful to the sound than the actual reduction of unwanted harmonics, noise and added tones.
Let's add to this discussion dynamic range. How much matters?
Can we appreciate the 96dB of dynamics available through a CD? The 70dB available through a vinyl record?
The answer lies in the recording itself.
For starters, we have to remember the background noise levels of our lives. Sitting alone in a quiet room might seem like the height of silence but, in fact, there's likely 30dB worth of noise even in the quietest of rooms.* Which means that anything you play has to be louder than that 30dB of background noise just to pull itself out of obscurity.
The most dynamic recordings I know require one to crank the level control higher than would normally be the case. Many of my favorite Reference Recordings of old, along with several Octave Recordings I've made, are mostly made up from low level music with the occasional blast of loudness.
The loudest passages are way louder than normal loud listening levels, but they work because they are relatively short and are no more than perhaps 20% of the entire musical piece. Compare that to the opposite where most of the recording is quite loud and you get the occasional quiet passage. That would not sound as dynamic as the opposite even though the actual dynamics are identical.
Dynamic recordings are almost always constructed with this 80/20 rule of 80% quiet in contrast to the 20% loudest passages.
It's the contrast of mostly quiet to occasionally loud that makes them work.
*I have told the story a few times of spending time in an anechoic chamber where the ambient noise level is low enough that over time one can hear the blood running through your ears. Weird.
