A lot of talk about the listening room... (already some herd feeling - imitation of the idea... trend... everyone is talking about it with a serious look)...
I'll tell you this: guys, if "carpet and furniture" is not enough in your case, then this is bad news ... There are VERY few who can really professionally take the correct measurements (skills and special equipment are needed) in the listening area, and after change the room and (or) adjust the music with the help of equalizers.
Beginner improvements for room acoustics; very helpful Darko video on reverb and RT60
I often find myself trying to help friends new to audio take their first steps toward improving their sound. Taming room reflection is, of course, the first step.
Many respond by saying some combination of "Why would I need that?" and "Isn't a rug and furniture enough?"
Darko's video explain the answer to both of these questions, and does so by explaining in layman's language what the sweet spot for reverb typically is, and why furniture and rugs are not often sufficient.
He describes a reasonable, middle way between going all out on room treatments and doing nothing. At the very least, he says at the end, do the ceilings.
Again, old news to many here, but possibly of use for some here and for anyone advising others.