Every speaker will sound bad in a bad room and I'm afraid to say but 3m by 3m is as worse as it can be, very tiny room and squared size is nearly impossible to get real good sound from.
I don't wand to offend you Whaleblue but the other worst thing you can do is damping in only one part of the frequency range and with curtains and rugs you only lowering HF. In most cases the HF is good if you get the midrange and bass absorption right.
I have a small room too, 3,15m by 4,49m with 2,47m height. I have used many broad band absorber and used a rug too, because you always been told here that a rug is a good thing. It was quite the opposite, after removing it the sound improved a lot.
There are people who are telling, you have to eliminate first reflexions and that is 100% true but you have to do it over a wide frequency range not only in the HF and that is exactly what isn't been told or considered by most.
People often say that you can treat a bad room without using proper acoustic room treatment but the truth is it is only wishful thinking, because the laws of physic will dictate quality of the sound.
Sure you can listen in every room and without any room treatment but every system won't show its full potential because the room modes and reflexions are mudding the sound.
The problem is that most people never will known how good it can sound because they think that a normal living room ist good.
@Chris You can find very good information here:
https://www.youtube.com/c/Acousticfields101/videos
and here:
https://www.youtube.com/user/GlennKuras/videos
You can hear the difference between a untreated and (even no very good room) here:
I would start to set up the speakers with the centre between two walls, not they typical front, back and side walls, instead a diagonal as a rectangular (I hope you understand what I'm trying to say because I'm getting to the boarder of my English language skills.
