Talking about RB I guess?
Input and output are two different things. What you do is, in recording mode you will set the recording level as close to 0dB as possible. That means you record at a maximum level, but still without distortion (in this case digital distortion, which is a crime for the ears, you will notice)

Playback level is like a mixing issue. You set those according to the mix, so it depends on all other instruments going on. Also as an output during recording you might set it different, because sometimes you want the mix louder than the incoming signal or vice versa.

If you talk about input/output of the windows mixer, then those are for the output general levels, all audio will go through. That is more a one time thing. You set the levels, when you are pleased with it, you will leave them alone.


I'll be back...