I use the S9 (original) with an 8830 and I can say that if I'm not careful, the volume can be painful.

Does the volume buttons work on the S9? Do you hear it increase/decrease when pressed? Not to suggest error, but you are pressing the buttons that control volume and not the ones on the other side? You do have to make sure that you feel the little "pop" when pressed.

I would guess that it is paired correctly or you would not hear from them at all.