For starters, your subwoofer looks to be about 10dB too hot - it will sound weird at first when you turn it down, so give it some time before you decide it sounds better turned up. (annoying psychoacoustics). You will probably end up somewhere around 6dB down from where you're at now, but try it knocked down 10 first and then turn it up a few dB later.
That said, it looks like you have a fundamental issue in the 35Hz region, and then a lot of modes in the 50-70Hz region. It would be easier to see if you set your waterfall to logarithmic instead of linear
Bass traps tend to be effective above 50Hz and then it's also going to clean up your octave around 150Hz too (provided it's implemented correctly).
Seeing the individual responses with the crossover of the receiver is always beneficial too...I wonder if you couldn't rotate the phase of your sub a bit to knock out the 80Hz peak and then bring up the response in the 60Hz region. Polarity inversion would be too much, but something more like 90 degrees.
Btw, are these plots smoothed at all? Unsmoothed would be the most informative at the lower frequencies.