-Battery Pack/Soundboard/Speaker: When I removed the pommel to inspect the inner workings of the saber I noted a black piece (which I suspect is the speaker) that I don't know how to get behind in order to access the battery back. If anyone can assist me with accessing the battery pack I would greatly appreciate your help.
A few suggestions:
Remove the pommel and, holding your Arbiter in a reverse grip, thrust the open end 2-3 times sharply downwards. This should encourage the speaker/battery pack to slide out the end of the hilt.
With the pommel off, tap the open end quite hard on something soft but firm - a cushion on the floor, for example.
With the blade out, slide something long and thin like a knitting needle or chopstick down from the emitter end and
gently push the battery back out the pommel end.
It's a snug fit and prevents the battery pack rattling around inside the hilt, where it might get damaged, but it can be a bit of a pain getting it out the first few times until you get the hang of it.
Good review, and glad you're enjoying your Arbiter. I do like the look of that hilt, but generally I prefer shorter hilts... Still, one to think about!