If it has 150hz instead of by-pass, then I'm sure it's the new firmware.

3 subs may blow you out of the room if they are mis-adjusted and you are sitting right at a sweet spot. 3 subs should however result in bass the has nearly equal SPL no matter where you sit in the room provided they are properly tweaked.

Think back to physics ripple tank experiments. Now you have to master the ripples young Padawan \:\) .

House of the Rising Sone
Out in the mid or far field
Dedicated mid-woofers are over-rated