I am a happy owner of a pair of JBL 4344MKII ... but I have a big problem : the level of one of the 275ND compression drivers is 6 dB under the normal level. Of course, I reversed the two 275ND to be shure that it was not a filter problem. Then I changed the diaphram with a new one and the problem remains. So it seems obvious that it is a compression driver problem, perhaps a magnet problem ?
My préamp is a TACT RCS2.2x and the amps are TACT 2150. As the preamp is a room correction préamp, it succeeds in giving a flat response curve by applying corrections and amplifying the frequencies between 1.3 and 8 kHz.
I mailed to Harman USA but never got an answer and Harman France told me that is was not possible to re magnetize the magnets of a 275ND.
Have you ever heard of such speakers problems ?
Excuse my very poor english and thank you for your help.