If a previous owner of the same speakers says that it just isn't that extended, then I'd go with that. The most important components in a stereo system are, in order: speakers, speaker amp synergy, amp, preamp, source.
There's only so much you can do to change the fundamental nature of the speakers, and speakers make the biggest difference.
There's only so much you can do to change the fundamental nature of the speakers, and speakers make the biggest difference.