Shortkeys for increase/decrease system volume ...

[mgpg89]

Is there any way to set one?

I'd like to have a separate shortkey (apart from the transport/volume control buttons on my MBP) so I can use multiclutch to control the system volume from my trackpad.

 

[hughvane]

Does your Macbook have a volume control speaker symbol in the top menu bar? Whilst I have a desktop machine and wired mouse, it's a simple enough action to click on that speaker symbol and adjust the volume from there.

 

[mustang_dvs]

Try [Shift]-[Volume] to see if it'll treat those as recordable shortcuts:

http://guides.macrumors.com/Keyboard_shortcuts