2-way speaker with best bass

Twoleftears, I take you are looking for a refined, highly resolved system in addition to bass? That is a speaker that would also qualify as a "best in class" type speaker for overall performance. I also assume your question is regradless of cost to some extent.

Certainly Brobdingnag has the best bass. Lilliput may offer some astute, refined, defined and well behaved speakers but the greatest among them can ne'er be more than a magnified miniature.

Sonus Faber Extrema and Usher BE-718 were the two best 2-way I have owned when come to bass quality and quantity.

Audio Note AN/E's. Various ways to place which results in various bass response. I prefer the paper cones. To my ears more tunefull. The hemp will probably play louder before breaking up.

These discussions of how low a frequency can be reproduced always lack one important detail...How loud? Earphones, with tiny "cones" can reproduce the lowest frequency, but at a volume so low that they need to be on the ear to be heard. Small loudspeakers can likewise deliver excellent LF performance, but not at a reasonable volume, particularly in view of the human ear's roll-off at low frequency. Large cone drivers can deliver LF at a volume which is realistic, and without the extreme distortion-producing cone excursion typical of small-driver systems trying for the lowest octave.