Hopefully, it’s just the space, not the speakers.
The reason I’m a big fan of level controls for tweeters and midranges is because speakers sound different in every space they find themselves. And positioning that was great there might not be best here.
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Others can tell you about room treatments, I start with the best I can get in the space.
Positioning: my starting position:
a. away from both side and rear walls to avoid both excess bass boost and out of time, but too early, reflections.
Ports: if side or rear, same concerns, AND, later, you might try stuffing the port, just to know if clearer, more defined ... some ports give measurable extension that the makers can use for specs, but add some mud, a bit or a bit more. Or, no mud here, but some mud there.
b. toe-in, aimed at the listening position. tweeters are narrow sound waves, the designed/published flat frequency charts were measured directly in front of them.
c. tweeters directed at seated ear height. I prefer height so that tweeter is below, and then tilted back so tweeter is directed slightly up, aimed to seated ear height. This, combined with toe-in alters the angles of reflections off all surfaces, (none parallel).
Some stands, i.e. KLH, were designed to do this, offered by KLH as options. You can improvise with temporary blocks under the front edge, and then come up with something better.
My speakers have a skirt that hides a 2x4 I put above the front wheels to raise the front 1-1/2" to tilt them back
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I would buy an inexpensive SPL meter (bottom hole for tripod), like this one:
and a CD with test tones
It doesn’t need to be professional, or perfectly calibrated, it will give you ’relative’ answers, for each test tone, + or - ___ db. And, when you reposition, show you the results ’relatively’.
Put the SPL on a tripod at seated ear height, make a chart, move them differently, toe them in differently, you might get lucky, sound as good, or even better.
Lastly, during the process, use your ears, get a friend with younger ears to help you, find your preference, i.e. ’flat’ isn’t always best.