According to Quad bass response is -3dB at 50 Hz. I agree that is not especially impressive for a big floorstanding speaker. Even with room/boundary gain you are not going to get much power in the low bass. So if your room is large they might actually sound a bit bass light with some music. I'd look for a speaker that is going to be no more than -3db down at around 30hz to 35hz if you want to give up the subs and not miss them.
Current Lash Up:
TEAC VRDS 701T > Sony TAE1000ESD > Krell KSA50S > JM Labs Focal Electra 926.