volume control

well, I have an echo miamidi soundcard and i use cool edit pro 2.0 for software. my problem is that i can't seem to get a decent volume level when i record. i go from my bass/guitar (or whatever i would be using at the time) to an amp, line out to my ART Nightbass SE preamp, and the left and right line outs to inputs one and two respectively on the soundcard. when I record the levels, they appear to be just fine on the computer, but when I want to listen to the recording, the sound is kind of distant, The only way i can hear it is if i turn volume on my speakers up all the way, and the sound still is pretty quiet! am i doing something wrong? Am i missing a piece of equipment to be able to hear my music? for the sound going out, I have a power amp connected to output one of the mia. Please help!
Charlie