I've been messing around with the EQ settings under 'Music' and the Late Night option seems to really boost the audio output across the board. Everything sounds louder and a bit fresher to my ears. My one beef with the 6s is I never considered the speaker quite as good as my old iPhone 5 for listening to Spotify, iTunes, or podcasts. This seems to remedy that. Also, since this setting boosts the audio loudness so much do I run the risk of damaging the speaker by using my phone this way? The highest I go when using the speaker is about 75% of capacity.