Base voice not loud enough

Do you have the interactive plan 24.99? If yes then you can go in the app and adjust the volume for the voice. If not you can still go in the keypad and do it that way as well.

Even at it's loudest, it's not very loud

What do you use the audio for?

I have voice on only nothing else and have it hidden away somewhere.

Dandy, some like to hear the base station voice/announcements (as a comfort/confidence thing), confirmation of arming/disarming, and the door chime - also, SS3's base station announces when component batteries are low (but only announces it once).