BMW Phatbox: how to set voice volume?

[Frankie]

Hello:

..first post here, although I used the official PB forums until they were shut down....

Question:

I have a BMW Phatbox system and I want to adjust the volume of the voice announcer when speed searching thru artist mode. Oddly enough, when searching incrementally (pushing the > button repeatedly) the first letter of each artist is announced at normal volume. But when searching quickly (push and hold > button after pushing the "m" button) the letters are announced at a reduced volume, barely audible.

What gives?