Sounds differences...

[fleabee]

Maybe its my imagination but why do bass recordings on albums sound so much fuller then live playing? Ive tried a million rigs/basses and cant seem to get the super full sound of recording. Is it due to the direct boxes?

[Freaky Fender]

It's due to a thing called Compression. Compression takes as bass sound as makes it a little more level in volume, by putting more volume in quiet spots.

Also, it's common to have about 2 or more tracks of bass going to the board. One mic'd rig, and one going from the bass straight to a direct box, then to the board.