Like paraneer says, it is best to match amp and speakers, however it is important to look at some specs carefully. The Paradigm 20 and B&W 685 have almost identical specs.
B&W 685 - 87db, 8 ohm dropping to a 3.5 ohm minimum
Paradigm 20 - 87db, 8 ohm dropping to a 3.45 ohm minimum
Paraneer's comment about a sensitivity rating of 90db for the Paradigm is a room sensitivity rating, not anechoic chamber which is 87db, the same as the B&W 685 anechoic rating. IMHO, the match of these to the amp is very similar.
The Dynaudio x14's spec is a low 85db, measuring even lower, so agree it should be avoided.