Depends on which of the mighty DBX you're referring to...not near as useful and cool at 160's or 163 but pretty equivalent to dual channel DBX of similar cost.
My preferred way to use 3630 for bass is to go first into Channel A for mild compression for basic level control...but even more so to get that midrange firmness of a little bit of the right comp setting. You'd want a low ratio 2:1 or less, a slow attack and a medium release setting. Set the threshold so your normal playing level is ~2dB into the comp. Then run the output of channel A into channel B to be set as a limiter: high ration ~10:1, fast attack and medium release settings. Have the threshold set so that only your most aggressive playing shows on the LED.
The final attack, release and threshold settings are to be to your style, chops and taste.
Try it, you'll dig.