I'll give it a shot man
usually running noise reduction creates what I call digital 'tinklies' which are far more annoying (to me anyway) than a constant hum you can tune out
but, since the hum (and hiss) is much louder on the phone channel than on Jack's (tiny hum, no hiss at all), I can run a compression algorithm on just that channel that should keep the tinklies from coming through because they're not loud enough to overcome the noise gate
once I get the right combination of EQ, noise reduction, compression and limiting it should be pretty standard to run on an average call and get consistent results
now, if I get someone who's voice is super quiet it's gonna throw everything out of whack, but we'll butter that bridge when we come to it
broadcast studios have racks of effects that run the whole time they're live that do all of this stuff in real-time, but you can get the same results with things like Adobe Audition pretty easily once the audio is recorded (or even live if you have a good enough computer) -- provided you have decent audio to work with from the get-go -- which we do
[EDIT] after tinkering for half an hour, here's a good example of what I mean:
also, two things to remember with the two batches of calls I've posted so far:
1) I wanted to show everyone what it sounded like raw with NO processing
2) when I first set up for calls I had Jack's voice at an appropriate volume so it wouldn't clip on the recording, however, where I had it set was a little too quiet, so when I turned Jack up so they could hear him better it didn't occur to me to turn the record level on the PC down to compensate (because I thought the mix coming out of the gizmo didn't change based on where the volume knobs were on the front...)
so there's going to be a little bit of a learning curve -- but once we get it straightened out we should get great results every time
