I'm editing in soundtrack pro, and im really new with the program. Is there any filter I can add to my guitar track to give it the deeper, lower sound of a bass? I also record with a Fostex MR-8mkII. Maybe it can be done directly through the recorder? Thanks.

It won't sound that great, but you can pitch shift the guitar down 1 octave (-12 steps). It works better if you post process the audio because the pitch shifter will glitch a little bit if you do it live.

I have done a live pitch shift down when our band was doing Nickelback's, "Figured You Out". But that was only 2 or 3 steps to get those low AH sounds. Because I have a lock nut style tremolo, retuning on the fly is not an option. It sounds kind of crappy on its own, but in the mix of the whole band, it's usable.

Your best option for playing guitar and making it come out as a bass is to use a midi pickup on the guitar and run it through a bass patch on whatever synth engine you're using.

-gb-

Yeah, pitch shifting won't sound that great. If the guitar sound is clean, you could go from Guitar to MIDI (Sonar 7 Producer includes such a utility), and then use MIDI to trigger bass guitar samples. That would actually sound like a bass, though it would have the rough edges between notes that you get with a non-massaged MIDI mock-up.

The best solution? Find a bass player...

I did the pitch shift on it because it was the simpliest route. This project isnt for anything too serious, so it should be sufficient. Thanks for your help guys.