Question on the finer points of Function keys

Do you have an 'fn' key, most likely in the lower left corner of the keyboard, or if you have a keyboard with separate numeric keypad and separate section for the arrow keys, then the 'fn' key may be in with the Home/End, Page Up/Down keys.

The 'fn' key can be used to invert the meaning of the F-keys. So a key that is an F10, can be fn-F10 for mute. If it is normally mute, then fn-F10 is an F10 key. This all depends on how you have the "Use all F1, F2, etc. keys as standard function keys" is set.

If you need the fast access F-keys for custom functions, but only need volume controls once in a while, then choose to use 'fn-F10' to get to mute, 'fn-F11' for volume down, and 'fn-F12' for sound up, and leave F10, F11 and F12 as standard function keys.

If you do not have an 'fn' key that could be a bit more difficult.

The other thing you could do is get a hotkey (keyboard shortcut) utility that will allow you to create your own shortcuts for functions that are easy to duplicate via System Preferences -> Keyboard -> Shortcuts. My perferred utility is BetterTouchTool, as it also gives me the ability to create a ton if touchpad gestures that speed up some of my most frequently used tasks

<http://www.boastr.net/>

But it happens to be a good keyboard shortcut utility. It does include the ability bind any hotkey you desire to keyboard functions such as mute, volume up/down, etc... So for example you could have Command-Option-M be mute if that was easier, or if you need F1 thru F8 as standard function keys, but still want F10 for mute, you can just map the standard function key F10 to mute (I actually do this for Stop/Start, Next song keys, where the rest of my function keys are standard F-keys used for other shortcuts).

System Preferences -> Security & Privacy

You want BetterTouchTool in the list of apps allowed to access the accessibility controls. If the padlock (3) is not open, you may need to click on it and enter your admin password.

Your screenshot shows the "Enabled" checkbox is unchecked

I did miss the part where you had F10 defined twice. Sorry.

I cannot really understand why it is not working for you. Some ideas (which may be desperate ideas)

I would start by deleting any unused excess mapping, and see if that affects things.

If F10 mute is not working as a global shortcut (which it really should), you could try creating a per App mapping for F10, with the apps you are most likely going to be using when you need to mute something:

While this should not be necessary, it is something you can experiment with.

While I like BetterTouchTool, and it has worked well for me, you could look for another keyboard shortcut utility.

Another utility you might try is Karabiner -> Preferences -> Change Key -> Change F1..F19 -> Change F1..F19 -> Change F1..F12 -> Change F10, F11, F12 to speaker controls:

Or maybe there is a different approach that could be taken.

If anyone else has some suggestions for allowing trevorfromshepparton to have F1-F9 as mappable function keys, but associate F10, F11, and F12 with mute, volume up/down, it would be appreciated.

trevorfromshepparton if you we do not resolve BetterTouchTool issues, _AND_ if no one else responses to this thread, you could start a new thread (as a lot of people may not look at this thread as it is current marked "Solved"). If a new thread does show up, I'll avoid contributing so that others might contribute. It would be good to tell in the new post the behavior you would like, and what you have tried, so that you do not get repeat suggestions.

I will try to keep contributing to this thread as long as you like.