What is your budget?
Without knowing that, it is difficult to give you a good informed answer, but, off the top of my head, I'd say try something from Sonus Faber or Avalon Acoustics. Both of them make some of the most non-fatiguing speaker that I know of, and yet are very high quality.
By the way, do you really want to upgrade as the title of your thread suggests, (i.e. do you wish to spend more money than the Sophia 2's cost?),
Or,
Do you just want to swap them out for something in the same ballpark?
Good Luck!
PS It might also help to know where you live, so that we don't suggest something that is not available in your area/country.
Without knowing that, it is difficult to give you a good informed answer, but, off the top of my head, I'd say try something from Sonus Faber or Avalon Acoustics. Both of them make some of the most non-fatiguing speaker that I know of, and yet are very high quality.
By the way, do you really want to upgrade as the title of your thread suggests, (i.e. do you wish to spend more money than the Sophia 2's cost?),
Or,
Do you just want to swap them out for something in the same ballpark?
Good Luck!
PS It might also help to know where you live, so that we don't suggest something that is not available in your area/country.