The audio volume sliders provided aren’t smooth, even though they’re sliders, so you have no fine-grained control. The lowest setting you can get for the notifications volume without muting them entirely is loud already. Maybe Android Assistant can come to the rescue.
UPDATE: Amazingly, Android Assistant can’t help. The sound system for the tablet is what’s ultimately to blame. It more-or-less rounds whatever arbitrary value you set, to whatever discrete values it allows. For example, set it low but above zero, and the sound system rounds it to zero. Mute! Not low-volume. At the lowest value that works, it’s already too loud.
SECOND update: Android Assistant isn’t to blame. It seems that Android (Gingerbread, anyway) will only set the volume at 14-percentage-point increments, because an HTC phone “ratchets” the volume similarly. This doesn’t absolve Samsung, though, because the phone in question has a useful volume range—the whole point of this post.
