I have a set of Monitor 7b's and used 2 different 6 1/2" drivers and I am having a problem with the speaker popping, bottoming out or something. I do like a lot of bass, but I'm not listening to it that loud I don't think. Is this normal for the MW6500 series of drivers? I don't want to damage them of course. Is there anything that may help me out on this happening? Stupid question maybe, but what about adding more acoustic stuffing to the box or something.