Like KR4 says, its the room. Start over with speaker placement. My favorite for proper bass response is the Sumiko master set method. Choose whichever works for you. I never found formulas of any kind to work for me. Good luck.
improving bass on large floorstanders....
I have some 3 way tower speakers that could use some bass improvement...however...if the results are minimal...i probably will pass...at any rate...would the addition of floor spikes or possibly a cable change be the answer?...I am looking for tighter, leaner bass if possible...thinking entry DH labs or Nordost...at any rates...what has worked/ not worked for others?