I think the best way to go about this is to make you banner show your viewers who you are.
For example, I do gaming reviews, and my banner is a Mario stage. Something easily recognizable, even for those who know little about gaming, and people will automatically know what to expect gaming reviews when they see it.
The banner on your channel certainly doesn't look bad, but I also don't have any idea what your channel is about when I look at it.
That's just my opinion, though. You banner most certainly doesn't look bad as is. =)