I second the poster above who said immersion is the way. A lot of folk music from eastern europe is asymmetrical time signatures, so stuff from Bulgaria, Macedonia, Hungary etc. There's a great Hungarian band called Besh O Drom who are worth checking out. Can recommend a band called Farmers Market. Also check out Chris Potter's Underground (there's more asymmetrical stuff on his latest release "Ultrahang") and check out any albums by Dave Holland on which Chris Potter plays ("Critical Mass", "Extended Play", "Not for Nothing", "Prime Directive","Pathways" etc), loads of odd time signature stuff but still absolutely grooving. (And as a bass player you owe it to yourself to check Dave Holland out if you haven't done so already, he's fantastic.) Also check out Avishai Cohen there's a fair smattering of odd time signatures there, I recommend starting with the album "Continuo", also an astounding bass player.