mavigozler

I have a entertainment-type laptop with internal speakers and I
occasionally connect the jack of an external speaker system (Logitech R20).

When I first connected it up, there was no sound coming out of the external
speakers, and then I fiddled with the Sound Control Panel and they were
working (setting default?)

Now I can't get the internal speakers to play a radio stream in a web
plugin, and the external speakers are not connected (I leave them at home).

What's the best way to deal with the system to play external speakers when
I have the jack in and internal speakers when I don't have it plugged?