Speakers or room

I have a similar situation.  I've done the best I can without compromising my room appearance too much but I know it's not ideal.  Much of my listening is background so I'm ok.  Jim Smith's book,  "Get Better Sound"  will help you a lot.  Most of his info is about room set up.  IMHO, get advice here, take your time and tweak as you can.  Good luck.   Doug

Type of amplifier has nothing to do with your specific problem.

Been there, done that!
Kenjit and others are absolutely correct.

Room correction will only do so much. You may as well tape those LS50’s to the sides of your head. You will never get sufficient bass from them.

Small monitors and skinny little towers shine for those audiophiles who sit in the sweet spot by themselves. Sure they’re a great speaker for experiencing the soundstage however for parties, gatherings or just walking around your home and listening to tunes they are cold with no umphh. Sorry.

How do I know?
Experience. I’ve owned B&W towers. See if any of this sounds familiar.

• to achieve low-end you’ve turned up the volume until the high-end is screeching in your ears
  
• moving speakers does nothing

Adding subwoofers will give you low sloppy bass but will not integrate well. You will find it does not help your mid-bass. Will not give you balanced sound.

How about room correction?
Room correction will help to reduce frequency cancelation giving you a smoother base response and less muddled highs. Will bring you no satisfaction.

Do you require a new room?
Ridiculous.

What you want?
You want to play anything through your system and have it sound great at any volume. Right?

• Sell your LS50’s while the reviews are still positive.  
  
• Get full range speakers. Read up on Klipsch Forte and Kipsch Cornwall for a start.
  
• Put down carpet.
  
• Get wife who lets you enjoy your music hobby. Haha. No really.

IMHO

I would have try for speaker placement first, and don't give too soon. OTOH, you can't change physics, and maybe the room is too tough of a situation to be handled speaker placement alone. Like many of us here, I have owned a number of speakers over the years and expect each set to have some good and bad about it. In general, I have to agree that the speaker needs to be 'sized' right for the room. No hurt in trying this pair in another room (smaller).

... I wasted too much money on room correction when I still had to replace speakers in the end. Do room correction, yes, but don’t go nuts until you get some worthy speakers. 
No speaker is too large. In fact I listen at a lower volume with large speakers.