The PD-90's look like they use pro audio drivers for the woofers (using folded accordion surrounds). That would match up with the extremely high 101db sensitivity. I would be very careful with your equipment choice because these will be very susceptible to the background hiss caused by high gain audio circuits (commonly in preamps and even input stages of amplifiers). They are also low impedance 4ohm speakers, which can be a challenge for some amplifiers to drive (especially on multiple-woofer configurations) If you really need a VERY LOUD speaker with your current amp, this could be a nice choice. But it really depends what kind of sound you are looking for.
I would actually recommend looking at Tyler Decade X SE series. The "D2x SE" is the same price as the PD-90s you are looking at. These SE series use the Seas Excel Magnesium drivers, which I have found to be extremely high resolution - clean and crisp and very exciting to listen to. The Seas softdome tweeter has a slight tube like signature (when compared to diamond or beryllium tweeters), and it has a very nice sound. As a result, this speaker is very forgiving and will sound great on a variety of equipment (though it might not sound as "real" as a diamond tweeter speaker).
http://www.tyleracoustics.com/Decade%20X%20SE.html
If you have good earbuds or computer speakers, these videos can give you a sense of what the speaker sounds like:
https://www.youtube.com/watch?v=yJgOGUY9VXc&t=190s
https://www.youtube.com/watch?v=sA7svLtICGw&t=85s
The following are recordings of a set of speakers I built using the Seas Excel Magnesium drivers.
https://www.youtube.com/watch?v=cyA_zyIMX1I
https://www.youtube.com/watch?v=OkOluvXmSiQ
Hope this helps.
