My speaker has 3 physical buttons in this order:
- volume down
- volume up
- mute
I find the order quite illogical, I would expect:
- volume up
- volume down
- mute

Is there any convention on the order of such buttons that the manufacturer should have followed?
EDIT: What we see is top horizontal face of the speaker, the minus button is closest to the front face while the mute button is furthest from the front face (thus from the user).