Alright, well what kind of mixer is it? Need the model. If you can provide a link to a product page with specifications on it, that would be best because it would give us an idea of what we're working with.
Are you on Tiger or Leopard? It really shouldn't be that difficult to get it working correctly (assuming the problem here is simply inexperience). Pending on which OS you are running, are you sure the mixer is compatible with that OS?
Are you a Logic newbie? Do you have experience with recording audio into Logic in any capacity?
Most importantly, what specifically appears to be the problem.
The more (yet concise) information you give us the better we can help you. Do you not hear anything at all when you play through your mixer?
Priority lies in these things:
1.) Setting the input gain on the mixer (should read a a gain knob near where you plug into the unit or at the top of the channel strip).
2.) Set the fader/level slider/knob to 0dB.
3.) Make sure Logics input on your track is selected as the input on your mixer.
- This should not be an issue if your drivers and all are installed correctly.
4.) Make sure the output is set correctly as well.
Because of programs like Logic only being able to use one audio driver/source at a time you cannot hear what you are playing because you don't have your speakers hooked up to the output of the mixer. Doing this should be one of your first steps after reading this. Connect the speakers to the mixer and play a song in iTunes or something to make sure you can hear playback (which indicates that everything is connected properly).
