um..not 1 but maybe not 4 either.
The firebox only has two line inputs (i think) and two Mic inputs (i think)
Each "input" is 1 track. If you plug your 4 mics into the mixer the mixer will "mix' all of the 4 (or 8 or 16 or 29543834 )mics into two tracks, a left and a right. Now, this is if you use only the line inputs on the rear.
You "Can" get 4 tracks by using both the XLR and the line inputs. You would plug only two mics into the mixer, pan one hard left and the other hard right, then you would put the mixer main outs or aux outs into the line in on the firebox.
After that you would connect two mics Directly to the firebox and there you go.
At least thats one way.
