Hi Colin,
You are of course right about the apparently larger magnet assembly on the JX92S, apologies for my misinformation. I was using a World Designs KEL84 with my older Jordans and this worked well despite the low 15 watts available. However, I suspected the WD was a little underpowered for the slightly less efficient Eikonas so have recently switched to a Leema Acoustics Pulse and the extra power available (80 watts) has improved things considerably.
Yesterday I had a friend round who also has the JX92's at home and he went off muttering about raising the money for a pair of Eikonas - enough said.