Hey guys, thought i would join in.
If you are trying to mic up and record a bass amp, i would recommend that you use 2 mics.
mic #1- Bass drum mic (if you have the stagg drum mic set then the bass drum mic in the set will work fine) - Stagg dm5010.
mic #2- Preferably a studio condenser mic (Stagg PGT-60 will do) or if that mic or similar mics are unavailable a basic vocal mic will do (the Stagg MD3000 Phil suggested earlier works quite well for this).
The idea is to use mainly mic#2 with a bit of mic#1 thrown in to help with the low end. Give it a try, mess around with the balance between the two mics ad let me know how you get on.