Phantom : low quality at normal volume

[superstock]

I listen at lowish volumes also and to my ear they have everything that I would expect or want in terms of clarity and extension while seeming true to the music.

There is a "moon" icon on Spark that if selected, limits dynamic for nighttime listen. Check that's not selected (orange outlined icon), otherwise you could send them back and enjoy your Jambox while save your cash for other nice things..