Bought new in December 2011 to complete a facade d & b MAX15 fixes in a room with a gauge of 140 people, driven by an amplifier d & b D6 (the facade is powered by a d & b D12), these subs are performing quite impressive relative to their size. They descend down and quite nicely.
Compared under the same conditions with a Q-South (18 ") d & b also, this sub has a worse impact on the bass drum and delivers a lower level. on the other hand of the cons low for synthetic sounds serious, this is very convincing and consistent with the existing facade.
The choice between the two (E15X or sub-Q) was that of reason with respect to neighbors and the homogeneity and consistency of the whole (the Sub-Q was not oversized and fully exploited, is also almost two times larger and more expensive).
For details, I do not find it as it omnidirectional.
The hall requires config to put the sub on the sides under the separate headings of 7 meters and if you get too close to the front of the stage we lose a lot of bass.
The quality / price ratio can only be judged as a whole + sub + amp head
which in this case amounts to approximately 10 000 € TTC for 3 concerts a week, with the power required by protecting pregnant, and carefree. For me the report is very good.