mid bass up front?

snappyjb67

currently i have polk dx 5.25 components up front. they have great midrange, but the mid bass is not that great. i was wondering if you would recomend putting an 8 in dx sub up front to help fill in. maybe bandpassed at 80hz-250hz?? any sugestions? also if i did something like this, since its over 80hz would it be omni-directional....?
thanks!