71 dB
Headphoneus Supremus
Even the most dynamic orchestral music doesn't need more than 80 dB of dynamic range (with safety margin, in practise even less). Why?I do know about this, the higher bit depth yields a lower noise floor, thus a higher dynamic range, it is true that 16 bits is already pretty sufficient, but like I mentioned, maybe, just maybe, loud orchestra pieces might benefit with a dynamic range over 96dB since it can reach 100 or more.
Reason 1: You don't listen to music in "total silence". You have background noise which is in a quiet living room about 30 dB.
Reason 2: Your hearing has a dynamic range of about 70 dBs are any moment in time. If you are listening to loud sounds, your threshold of hearing rise and in order to hear very quiet sounds (below 20-30 dB) you need to stay in silence for a while. That's why you can't experience the large dynamic changes in music beyond about 70 dB even if you listened to it in a very quiet anechoic chamber.
Reason 3: Electronics has a noise floor too. Getting more than 90 dB of electronic dynamic range is challenging. But your headphone amp is rated at 110 dB of signal to noise ratio you say? Yeah, maybe, but that's a marketing measurement meaning maybe in an optimal situation for optimal signal you might get something like that, not with any random signal in typical listening.
Reason 4: Changes in dynamics more than 60 dBs with music is annoying. There is a reason why popular music has so flat dynamics, but compressing the dynamics too much makes the music dead too, so there is a optimal range for dynamics in music of 15-30 dB.
Vinyl gives 60 dB (10 bits worth) of dynamic range at best. Vinyl-lovers are happy with that. My rule of thumb is that consumer audio doen't need more than 13 bits (78 dB) of dynamic range if used well. That's why 16 bits is even overkill and definitely enough. In music production things are different and 24 bits have benefits, but consumers need only 13 well used bits (whole scaled used + properly dithered).