Are you using a 4-string, 5-string, ? What volume level(s) are typical for your playing? It all makes a difference.
As fflbrgst stated, you have to match freq ranges. You ALSO must consider volume, as, if your volume is much higher on the bass, you could "blow" your speaker. Bass speakers typically have greater travel ranges than guitar speakers, as the bass freqs will push a cone farther (physically) than the higher freqs of the guitar, especially if the volume is up there.
I'd try it at very low volumes at first and see how that works for you. If you MUST go to higher volumes, mic it and push that into your PA.
Good luck with it.