Sound settings on the Mac

[LuKreme]

I normally use my USB Headset on my Mac.  However, when I unplug the  
headset, the OS switches to "INternal Speakers" and I would like it  
to switch to Line Out instead (since that is where my speakers are  
connected).

However, I cannot seem to find any setting or preference for this,  
and despite my frequent tango with the settings I end up having to  
open the Sound Prefs and manually switch from Internal Speakers to  
Line out.

Anything I can do about it?

(I do have the alerts and effects set to the Internal Speakers  
because that is where I want those sounds to play through).

-- 
Naked blonde walks into a bar with a poodle under one arm, and a two- 
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needing a drink. Naked lady says…