Here is a frequency chart: http://www.phy.mtu.edu/~suits/notefreqs.html
The open low B string (i.e. B0), on a "standard tuned" 5 string bass is 31 Hz.
The open G (i.e. G2) string is 98 Hz.
So, if it's a 24 fret bass, the highest G (i.e. G string, 24th fret, aka G4) is 392 Hz.
All that said, a LOT of what you hear when you play any of those notes is higher frequency harmonics/overtones.
In other words, even though the range of the fundamental notes is 30 - 400 Hz, if you were to use an EQ to kill everything above 400, you would easily tell that you have cut out a LOT of your sound.