So I have a Mac, the latest Band in a Box, and a Zoom B3 multieffects, which I am using as a USB interface for my bass guitar.

I would like to record along with BiaB, preferably sending to Garageband with a track for the bass and another for the BiaB audio. I could also use Audacity, if I had to.

I have figured out that I can use the DAW plugin mode to send over the rendered track to Garageband, and then in a second take, record the bass on another track. That's nice, but I'm mostly doing this for practice, and would like to follow along with the chart. (I know I could also output to a file, drag the file into Garageband, which it seems like the DAW Drop thing is a quick way to do this.)

I tried using Soundflower and the LineIn app, like this:
1) Everything in Soundflowerbed set to "none" or "off"
2) LineIn app set with the Zoom as input, and output to Soundflower channels 3 and 4.
3) System sound output to Soundflower. System input to Zoom.
4) On the Zoom, master volume set to DAW (No monitor)
5) In Garageband, Input set to Soundflower, output to Zoom
6) Two stereo tracks, one being Soundflower 1/2 (the Mac's sound, i.e. BiaB) and the other Soundflower 3/4 (the bass)

This *almost* works. But the bass latency is horrible, and the volume on both is really low.

Is there something I'm missing? All of the stuff I have seen about recording either is for the PC, or for MIDI instruments. Does anybody have something workable? Do I need to go buy a "real" audio interface? Or should I give up and go buy a portastudio or audio recorder and just dump the computer and the bass to that?

Thanks,
Jon