Sound Output confusion

[Spike Spiegel]

I just got my Mac Pro today, and am setting it up as we speak. I set up the speakers by selecting "external speakers" in the output menu. Now, on my previous PowerMac, if I were using the speakers, but then wanted to use headphones, all I had to do was turn the external speakers all the way down; the headphones and the speakers would work simultaneously. Am I correct in my discovery that I would now have to switch the output selection in System Prefs every time I wanted to swap between the two devices? If not, does anyone know a work-around?