3k is a quite a bit of rms wattage. Have you confirmed that your amp is near the clipping point? If it is then I'd say you probably want to focus on your enclosure before you worry about your amp at this point. Maybe it's a difference in preference, I like bass a lot but I'd call 3k in a ported enclosure quite loud except for the very low end. You can use that same chart I linked earlier, go to 50 volume, disconnect the subwoofers and play a variety of tones from super low to 100hz, whichever is the highest adjust the gain until that tone reaches the voltage that corresponds to 3k and your impedance configuration.