Bass to DI box, cable from DI box to amp is typically how this is done. In this instance, all bass tones heard by the audience will be off of your bass ONLY. So if you have a pre-amp on your bass and you adjust the Bass or Treble knobs, the sound man will get the results of the tone change. This can be good or bad depending on the sound man. Small boosts or cuts are usually OK. Drastic changes will ANGER most.
Keep in mind that if you unplug the bass, the sound man will get a loud pop/click sound of you unplugging. This is where a Mute pedal is crucial right before the DI box. Almost every bass head has a direct out connection and a mute switch on it. You can easily send a PRE signal (Just the sound of whatever is plugged into the input jack of the head) from the head and gain a mute switch in the process. You can also send a POST signal from the amp head to the sound man. This signal will include all of the tone changes you have made on the dials of the head. It may or may not sound good in the room; talk to the sound man about it and see what he wants.
Lastly, I suggest being more patient in waiting for responses to posts. 19 minutes is a bit short and many of us are not Rock Stars and actually have to work in the day time. I am using my lunch hour to type this....