Bass Effects Pedals?

Question

I noticed a lot of people use them, but what do they do besides from adding distortion?

Answer 1

Useful bass effects -
EQ
Compression (for a tighter, fuller sound)
Envelope-shaped wah (for a funky bwauwww kind of sound)
Flanger (for a sound that shifts subtly over time)
Octaving (e.g. a deep sub an octave below the basic note)

For me good distortion is the best one. If you put too much distortion on a bass sound you lose the body, so the distortion effect has to fit the basic sound. It's hard to get just right.

Answer 2

In addition to those mentionedby Dr Death.

Delay - repeats what you play after an interval. This can be used to provide an "echo" of what you play.

Reverb - creates false subtle echos that make it sound as if you are in a bigger room.