Yeah the h4n is really tricky. I still don't have it dialed in exactly. I may just end up buying a real compressor and eventually I'd like to get a Mackie mixer. Right now I'm going Heil > Behringer > h4n > Mac/Garage Band. That might not be optimal but it's working for me. Without the effects in Garage band the sound is just ok. I can send Garage Band's audio out to Screeny (for screencasts/voice overs) using a little (free) app called Soundflower.
Thanks for your help Boswell. I really appreciate it.
I think I'm going to sell my equipment and buy new stuff. I just can't get the sound right. It sounds all muffled, not clear, crisp, and compressed like radio. I'm looking into something like the Joemeek 3Q. A solid preamp, compressor, EQ.