+1 @ acoustically treated room.
Finished building mine end of 2019. My music experience has evolved 10 fold ever since. However it is a tough sale for a lot of audiophiles, specially married ones, since they have to be worried about messing up the looks of their rooms to do so.
Hence the never ending equipment upgrades. And that's great for the audio business, room treatment, not so much. With about 50k in gear total, I have come to the realization that it is already well above any expectations I ever had about sound quality. It is a blessing to be at peace with sound in only 3 years and I would never have achieved that in a lifetime without building the house of stereo, even so it obviously came at a high cost. I always thought the systems I had in various homes through the years were excellent. I could not have been more wrong. A properly built and treated room is essential if you are serious about sound.
On the other end, if you are strictly a music lover, a boom box will do, I have one.