Here are some System Settings that I use to optimize the volume on my Clip Sport…
Anytime I update the FirmWare or need to use the internal Restore command (almost never), I select North America for the region. Sometimes the player asks to confirm this selection a few times. The prompt usually goes away after 3 times (?)
North America Region enables the player to use the “Normal” volume.
Settings menu -> System Settings
-> Volume (Normal setting is 2x louder than High)
-> Equalizer (Pop setting is 2x louder than Normal)
-> Replay Gain (I use Off, but you could try the Pre-gain 4.5db)
Maybe report your results here to inform Clip Jam (and Sport) users.