Windows:
http://mumble.comdownload and install
ensure your microphone is enabled in windows before you try to set up in mumble
Linux:
use your lovely package manager
-> sudo apt-get install mumble
when setting up:
Recommend using push to talk but REMEMBER to not use a key that spring uses such as r for repair ;)
to connect:
hit Add New...
Label it spring or something easy to remember
the address is: springrts.com
the port can be left as the default and that is: 64738
username: your ZK username
then select it from the list (its what you called it in label)
and hit connect.
scroll down to 0-K and double click it!