many things influence bass responce, while amp power does play a part it is definatly not the most important
IMHO the most important is the room position (the corner of the room usualy give the best responce) try a few diff positions and see what happens
2nd the size of ur room. this requires som higher level math than i am particularly comfortable. needless to say i understand the theroy even if i can explain the math. frequency sound waves equate to physical dimensions (these numbers are wrong) but for example say a 20Hz wave equals 20ft if ur room is only19ft u may not be able to hear a 20Hz signal. it may be possible to hear it if ur room were 1/4 of the signal lenght or 1/2 the lenght . if the sound wave strikes the wall incorrectly postioned its reflection can cancel out the orginal wave.
3rd the size of the driver/ enclosure.... the driver must be able to move enought air to produce the desired sound . the enclosure is subject to the same rules as the room in reguards to wave lenght (again that damn math
lastly is probably the power behind the driver (ur orginal question)
hope this helped