Mic choice is of the utmost importance! After years of engineering bad sounding upright bass sounds...

this is the best advice I've ever received, from some truly world class engineers.
Shure KSM32 is a fantastic mic that sounds great on the bass, as well as dang near anything else you can throw at it. Cheap on ebay, and worth 5x the asking price.
Placement is really significant as well- 6-12 inches in front of the bridge is usually best, blended with a DI line from your PU, preferably with the best quality DI you can afford.
The reason for not using the "traditional" placement in front of an f- hole is twofold: The f holes produce massive bursts of air, perceived as excessive low end. As well, the lobes of the top resonate topically at different levels for different notes, so favoring one side will produce a signal that needs to be heavily eq'd to sound natural.
This solution is the most economic way I've found to get consistently great (or at least accurate) sounds without spending all day compensating for bad placement, the wrong mic, and crappy direct boxes.
Good luck!