VT Bass Speaker Emulator question.
 

From my understanding, the speaker emulator is supposed to simulate the affect of a speaker.

If I'm using the pedal in a live setting, without a PA, using just my head and cab, is it best to keep the emulator off?

You won't damage your equipment one way or the other, if that's your concern. It's really just a different EQ curve and whichever setting sounds best to you is the right one - i prefer the speaker sim to be off, amped or direct.