Hi guys, i got the interface the Presonus Firebox. I want to rec my scratch separated from beat and trigger some sounds from synth. So i thought in connecting the turntable in mic (1), a synth in instrument (2) and the beat in line in (3/4) from back panel. When I connected the master of the mixer to the house speakers (not monitors), the sound was very low. This happens in the mic (1) and in instruments (2), but line in sounded good. Could it be that I have problems with connections? or maybe the version of my mac is incompatible to the interface (yosemite). Does someone know about this? Thanks!