Is your space as symmetrical as possible? Are your speakers facing down the long way of your room? Is your listening position reflection free? Google "Reflection Free Zone".
Precise speaker and listening placement are crucial to effective mix translation to systems outside your own studio. As a rule of thumb place nothing at 50 percent of the height, width or depth of your room, particularly your low end driver and your listening position.
If you are a bit techie get a cheap Behringer omni measurement mic (ECM5000 or something - google it) and download REW (Room EQ Wizard) and start moving your speakers and listening position to get as flat a low end as possible. Use decent stands (I made my own and they are sand filled) and Blu Tac to place the speakers firmly on the stand.
As a starting point place the speaker 20%ish in from the front wall of your room with the tweeters pointing right at your ears (not your forehead). Start with listening position at 38% down. I will repeat that placing anything at a 50% position relative to any of the 3 dimensions usually results in hateful colouration.
Having said this these figures are starting points and did not work that well for me! I ended up much closer than 38% to my front wall for flatest response in my studio.
Then listen to and mix lots of music to get atuned to the space and your speakers.
None of this will cost you much apart from time and hard work. Moving speakers around ad infinitum is pretty boring but you can improve things greatly. Understanding how the software displays information is important to making the right placement decisions.
The best forum for advice here is John L Sayers place (Google it). There are lots of very clever people there who can help far more than I.
USE EQ ONLY ONCE YOU HAVE DONE ALL THIS. IT IS A LAST RESORT AND NOT REALLY AN EFFECTIVE SOLUTION FOR MOST PROBLEMS.
Hope this helps
Tony