HUBs and USB Config? DJM, CDJ NEXUS

thanks for the help,

I have a macbook pro (2012) latest software,

DJM 2000 NEXUS

CDJ 2000 NEXUS X 2

TRAKTOR PRO 2

4 port usb external hub

TRAKTOR F1.  I keep all my music on an external hard drive but as you can imagine i only have 2 ports on my mac and 5 inputs i want to connect.  my i intention is to plug 2 cdjs, external hard drive and f1 into the hub and my djm 2000 straight into the mac.  I've tried this and it worked , 2 weeks later i tried it again however the external hard drive doesn't recognise.  It does recognise when plugged in to the mac without the HUB.  so I'm guessing its under powered, so if i plug the djm, 2 x cdjs and the f1 into the hub will the dim be recognised ??  i am not that swept up on all this and its driving me mad,  any takers?