Spotify through Android Auto
I'm no audiophile but I was pretty disappointed with the sound coming out of the speakers in my Bolt LT package when playing music through Spotify.
I played with the Bolt tone settings and found I ran out of room pretty quick.
However I did find that if you enable equalizer in the Spotify app on your phone you have a lot more room to play. I got to the point where I set the Spotify equalizer to "Normal" and on the Bolt audio settings adjusted Bass, Mid and Treble all up +3 marks. This made the bass and mids really beef up. I'm pretty happy with the sound now and know I have a lot more room to play with.
I would have left all the Bolt tone settings at 0 and adjusted the eq in Spotify, but I didn't want to mess around with the Spotify eq every time I connected it to other devices.
One annoying thing I've noticed is that when you skip to the next track it takes about a second for the Spotify eq level to kick in.