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View Full Version : 2445J diaphragm markings?



oldsoundz
01-28-2014, 03:06 PM
I have some 2445J all labeled 16 ohm, that all read more like 8. I opened them to see if they may have new dia's. None of them have any identifying marks. Should they if they are JBL? Are these replacements?

Thanks for any help.

grumpy
01-28-2014, 06:32 PM
Red or green coloring on terminal?
8 ohms DC may not be wrong ... Lookup spec.
If there's a + embossed in the mounting ring,
or a sticker with a + printed, it's likely aftermarket.

oldsoundz
01-28-2014, 07:04 PM
I didn't see any sticker or stamping. There is a red mark, I think I noticed on all of them.

http://i100.photobucket.com/albums/m21/oldsoundz/DSC04419.jpg (http://s100.photobucket.com/user/oldsoundz/media/DSC04419.jpg.html)

grumpy
01-28-2014, 07:17 PM
Looks like a stock JBL 16 ohm Ti diaphragm.

oldsoundz
01-29-2014, 05:30 AM
Looks like a stock JBL 16 ohm Ti diaphragm.

Thanks Grumpy. I fully expected to see a part number sticker or something on them. Learn something new every day.

Cheers

Fort Knox
01-29-2014, 05:36 AM
Red or green coloring on terminal?
8 ohms DC may not be wrong ... Lookup spec.
If there's a + embossed in the mounting ring,
or a sticker with a + printed, it's likely aftermarket.

Speaker readings ..are usually less than rated ...the nominal imp. like 4 ohms
means it draws more heat and should be used w/a 4 ohm amp...
the impedance curve (operating) could be 5-50 ohms (depending on freq..)
you can visually see larger and fewer wire windings on a low, 4 ohm sp,...when
comp. to a 8 or 16 ohm sp. :)

grumpy
01-29-2014, 11:19 AM
As mentioned, see:

http://www.jblpro.com/pub/components/2445j.pdf

~8.5 Ohms is normal for the "J" suffix model.