I have a pair of speakers in a good mid-fi quality. Before I started to upgrade, I tried to understand what simple things I can do to get the best out of my current setup. Things I have to do, even with new and improved speakers.
The one thing that ended this experience were the resonances in my living room. I have them in low frequency (44, 88Hz) and higher frequency (300- something) that just limited the maximum volume of the music to extremely low levels.
Now, with a great set of speakers, you don't want these limits. But to get rid of them, I'd have to replace my beautiful wooden floor with a carpet, cover my leather sofa, hang thick curtains in front of my 6 meter window, probably add an acoustic ceiling and buy some ultra deep resonance absorbers to put into the corners of my room. Easily 15.000 Euros or more.
-- NEVER -- !! I still want to live there! And I love wood, leather and glass.
That's why I invested in a really decent headphone amp and a set of great cans. One of the good decisions I made, if you ask me.
Please have a very close look into the demo room of your hifi dealers. They have all the things installed that I described to achieve the best possible acoustics. Then think if you really want this in your living rooms, before you invest all your money in speakers, expensive pre- amps etc. only to discover that this was only the start and there is much more to come.