Crossover is 80hz. Results are for sub only. Mains off. Values are compensated with corrections. (RS SPL Meter) Sub is shoved up in the front corner of a 4300 cubic feet room with a large 5 foot X 9 foot opening into another room with approximately 6000 cubic feet. (I should probably install some french doors in this opening but it wouldn't pass the WAF.) I have already set up a couple of presets on my BFD to smooth out this response but am always open to other suggestions that I might input into another preset. Then I can switch between the presets and determine what sounds best to me. I'd like to end up with 3-4 presets total. I believe I would favor a house curve rather than flat. I believe this will help me when I get to the 50hz dip as well. I have had some strange experiences with this 50hz dip. I tried boosting it up about 8-10db and got rid of a good bit of it. But, when I was running my test tones with the boost, that 50hz tone sounded really strange, as if the amp was struggling. The tone did not sound smooth like the other tones. It sounded too loud althought the reading only increased 8-10db. I suppose the headroom was sucked up, even though I was playing only the one tone. This really doesn't make sense to me. I might would understand it if I were playing several octaves of tones but this is just 1/6 octave playing. I tried +6db and got the same. When listening I noticed the same thing, so I notched the boost back down to +3db and it sounded much better. It didn't sound like I was missing anything, but I still have a huge dip at that range. It actually made me wonder if I was getting the right reading at 50hz. But I've always measured this dip in that range, even when I ran the sweep on Spectra Plus. At any rate, I'm open for suggestions and am curious as to how others might set up their BFD if they had this same response and set up (obviously without the benefit of a listen).