As a factual engineering reality check, it's highly unlikely that your cabinet (or any ceramic driver 210 of that size) can achieve 101dB/1W/1M average sensitivity AND simultaneously have an "RMS" rating of 400 watts. It's outside of the tradeoff envelope for just about every dynamic loudspeaker I have ever worked with. Now the way sensitivity is defined is not stated, but if it's peak sensitivity, then that does not translate into any usable SPL metric because it depends entirely on where the peak is measured and what multiplying factor is used in the conversion from average to peak. It could easily be different than the average number by as much as 6dB, which is why peak sensitivity is not a good number to rely on.
Here's why:
For example, factors that can affect the peak (versus average) sensitivity number include the Q of the low frequency measuring the peak in an underdamped design, measuring the response where the tweeter dominates (because a tweeter will almost always have a raw sensitivity of >103dB/1W/1M), using the simple mathematical conversion of adding 3dB to the average (or "RMS") number to convert to peak based on the shape of the test waveform, using something other than 1/2-space boundary conditions for measurement/calculation (using 1/4-space conditions, simple corner loading, would add 3dB to the 1/2-space number), etc. Also note that just about every manufacturer these days uses calculated SPL based on small signal models, which do not factor power compression losses into the maximum SPL performance results. Where power compression becomes a significant factor, the calculated maximum SPL (from the large signal model) results will differ significantly from the small signal model, which is why some designers look very carefully at what happens at the outside edges of the performance limits rather than ignoring the possible effects of power compression non-linearity.
Now it's possible to achieve 101dB/1W/1M average sensitivity using a (high performance) Neo driver, but not at 40Hz in a cabinet that small, and not at that power level. This is because it's possible to make the motor stronger and the field more focused by using a stronger interior magnetic slug, which allows for slightly "better" gap geometry and more efficient use of the magnetic field through the voice coil. But, in order to achieve this kind of sensitivity at 40-45Hz, a larger cabinet (larger internal volume) is needed in order to support the necessary tuning for this kind of low frequency extension. This is the struggle that EVERY manufacturer deals with, and the physics is uncompromising to say the least
Hope this helps bring together the difference between theoretical and real world performance differences and helps folks better understand why it's important to recognize how better to manage real world performance compromises. This has nothing to do specifically with the cabinets "Bass40Hz" is using, but applies equally to this class of compact speaker cabinets by every manufacturer.
