First of all here are some graphs of my corrections before and after. The sub is a 142.5l vented box tuned to 18hz with a 12" Dayton Titanic MK3 and 250 PE plate amp. Before I added the BFD I had my reciever attentuating the LFE 10db plus taking another 6db off the top of that for a total of -16db. When I added the BFD I ended up running the LFE at +5db. I also ended up having to turn the sub up from 1/8th on the amp to just over 1/3rd to calibrate it with my mains after corrections. Now when testing with some bass heavy material I can hear distortion that wasn't there before the BFD. What does clipping sound like versus bottoming? Identifying the distortion would probably help to know how to fix it. I was thinking it could be bottoming since I thought I'd gain amp headroom, but I did turn the amp gain up quite a bit. What can I do to minimize this?