The R909s dont need it because of their design, but open baffles are capable of making a healthy amount of low end if you compensate for the low end drop with an EQ
@phasey Why do Reference 909 not need EQ because of their design? As far as I recall they're plain-jane, drivers-in-a-plank-style open baffle speakers. Although their woofers are quite substantial they should have the same low-end behavior as other, similarly designed open-baffle speakers like Caladans and such. Thanks!