[JohnM]

The target level is too low on those plots, should be at least 80dB and possibly higher. Is the measurement of the sub alone? If so, is there any crossover active? The Target Settings should be set to correspond to the measurement, so if you were making a measurement of both the sub and a main speaker together (for example) the target should be set for a full range speaker as that is what the combination of sub+main should ideally achieve, if it is just the sub then the target crossover should correspond to the crossover being applied to the sub - if you are connected through an AV receiver it should be the receivers sub crossover setting, if directly to the sub or to the sub through a BFD it should be the sub's own crossover setting.