If the driver is expected to produce all the range up to 150, that might take more power demand from the amp, hence a reduction in power being delivered to the "slam" frequencies. By rolling off the 80 to 150 hz range, it's leaving more for the lower frequencies upon demand. That could explain why I am feeling more in the other room. If there is a 3 db reduction in demand from the lack of using higher frequencies, then in effect you are doubling the power to the lower ones.

Please don't think that I know what I am talking about, I am not an electrical engineer! I am only asking questions of the in house professors.