Not a chance. Speakers that small, single driver or not, just can't possibly move the volume of air to produce the illusion of some kind of 'SLAM' much less the impact of a live orchestra. That's not to say they'll not be fun to listen to, and do a fine job at reproducing a recording, but I don't think it's going in the right direction if your friend is looking for "SLAM". A good set of floorstanders might serve him much better. A 40wpc tube amp is going to need a pretty efficient speaker to produce a sense of "SLAM". I've recommended them before, and will again: Soliloquy 5.3's if you don't mind that the company is no longer in business. Used prices have been a bargain lately because of that. They are efficient enough (92db) and capable of some serious low end in room of that size. If you hold out long enough you may be able ot find a pair for $600-700. All the qualities he wants would be there, though I don't really recall being wowed nor disgruntled by the treble so don't know about that one. Images great...smooth, natural,yeah, certainly. Great all around speaker and very tube-friendly.
Good luck.
Marco
Good luck.
Marco