Your experience makes sense, given the 2Pi's behaviour in the bass. They show a little 'peaking' (max. ~1dB) from 60-160Hz & a fairly slow roll-off down to ~33Hz (-3dB just over 40Hz). The little peak in the mid/upper bass area can in some cases 'mask' the deep bass, especially if 1)your room is sub-happy, 2)you are used to a sub, & 3)the Pi's arent placed optimally.It's nice you seem to be tweaking your way to make these speakers do their best! Good luck.