What do u think about this speaker copmaring new speaker around the 5K?is it good invesmentThat's are really difficult question to answer. None of us knows all of the 5k speakers out there, Scubi...
Anyway, the Extrema perform very well. Despite their age, many other speakers will not perform better within the Extremas' optimum operating range...
They were also very expensive speakers. If you're ready to buy a used pair, make sure the drive units are in as good a condition as they can reasonably be. Is this pair expensive?
They do need a powerful amplifier. I don't know if a digital amp will do the trick -- why not? In fact, instead of purchasing a branded product (Nuforce etc) why not diy and buy from Hypex in the Netherlands ($~300). I used a standard SS amp when I used them.
Cheers