Probably. One of the forum members had 2x EP600 and still wasn't getting great bass. We knew it had to be going somewhere, so after some wandering around he found that there was fantastic bass in the computer room around the corner and maybe 15' away from the listening area.

Putting the subwoofers in the computer room probably would have worked well (things are pretty symmetrical at those frequencies, that's why sub crawls work so well) but there just wasn't enough room ;\)

M60ti, VP180, QS8, M2ti, EP500, PC-Plus 20-39
M5HP, M40ti, Sierra-1
LFR1100 active, ADA1500-4 and -8