Lots of interesting responses. I’ll only add that Mr. Bourne isn’t completely wrong. Lots of $$$ have been burned component swapping for results that don’t exist. I’d also urge caution following those who tie the price tag directly to the improvement expected. Far too much snake oil in this hobby. Price tag is often a meaningless gauge of performance. Optimizing your room should be high on the list as well.
Consider checking out and carefully integrating a nice sub. I know it’s not what you asked but if you haven’t given that a try, the benefit can be substantial even with full range speakers.