Greetings all. I got a jbl 2425h ceramic comp driver off of ebay for a song ( $75). The ad claimed the driver was working, and had a jbl diaphragm. Upon receiving my new toy, I inspected the driver to find the shippers had failed to destroy it! Bonus!!! Tonight, I fired it up, and it does seam to work well. It sounds clean, seems to cover the range I have dialed in ( 1k-8.5k). It does seem to be a hair quiet compared to my pair of similar drivers ( ducane alnico comps with 2425h diaphragms). Out of curiosity, I opened up the back to inspect further. I found a flat gray dome that does look like what I remember a 2425 titanium diaphragm looking like.
My question is how exactly can I tell it's a real jbl diaphragm, and not some cheap after market replacement? I can up-load some pics if necessary, but I'm betting one of the pros on here can clue me into the markings, or sticker codes that will set my mind at ease about this.