the only thing i can say to this is that a couple of dB more or less here and there makes a much smaller difference than the room where you install speakers. Every room is different; a speaker can sound bad or good, depending on the room.
they're both (room/speaker) coupled together.
when you have good speakers, to get good sound, you need a room that's kind on the sound, which means a room always needs room "treatment", like rugs, soft furniture somewhere, etc.
This tames the sound wave reflections in a room.
when you go in an empty room and you clap your hands, you hear an echo. this is how good sound can come out bad in your ears, too many reflections.
if you feel that a speaker will not go down in frequencies as much as you'd like, then you have a choice:
1: get large towers; if this is not good enough, then you can
2: get smaller towers and get a sub that will go down in frequencies to where you want.
hope this helps. :-)
