>acoustically treated makes a big difference.
Sing it, brother!
While I was waiting for my room to get finished, I had my speakers in my living room, and I had weeks to go before the room was going to be done, so I hooked them up. The sound was unimpressive to say the least. Flabby sound and only hints of imaging.
Once I moved them into the treated room, I thought I had the world's best speakers (and I still do). The difference is all but unbelievable. Everything is clean and crisp.
I still stare in horror at folk who will drop $100 on magic fuses and $1000+ on magic cables, and are listening to music in a 10x12x8 room without any attempt at treatment. Who knows, maybe the cables did make a difference - but there's no way to tell under all the room's smear and ringing.
Fix your room, then upgrade your speakers. *Then* worry about the rest. You may find you don't need to do much, once you're in control of the room.