I recently replaced a diaphragm on a JBL 2426 driver. Included with the diaphragm, a genuine JBL part, was a little folder with "Warning" printed on it. Inside it said: "This part is NOT self-centering! This product should be installed by an authorized factory trained technician." Then they went on to talk about the centering of the voice coil within the magnetic gap and special test equipment. Really? I just stuck it in and it worked- just as I have done with many other ones over the years. Was that some kind of generic waiver, or am I doing something stupid?