View Full Version : What size screws for Midrange Cups

04-16-2010, 02:53 PM
Well hopefully these are all the same as the mids in question are up on a shelf way in the back. Suspect Harman period as have seen some Infinity mids online with what looks like the same backing cup with screws.

Currently have the backing cups tacked down with hot glue, but if can procure the screws to batten down the cups would be great.

So as the header states would like to know size are the screws that pass through the cups into the back of the magnet.

Thanks all

Mr. Widget
04-17-2010, 02:20 PM
Could you be more specific? Which mids are you asking about, or if you don't know, which speakers were they used in?


04-17-2010, 03:01 PM
Thanks, needed something to do while the glue dries on a Advent Prodigy woofer refoam ;), I dug said JBL Mids off the shelf, person I got them from really went to town with the hot glue was worried might break the backing cup there for a bit.

P/N on cups: 902-2659, 66887 under that

Mids: Model #4505-G1, p/n 7075-01, 430-HSAB


Mr. Widget
04-17-2010, 03:28 PM
P/N on cups: 902-2659, 66887 under that

Mids: Model #4505-G1, p/n 7075-01, 430-HSABNone of that means anything to me... perhaps it will to someone else. Do you know what speaker system these came from? From which era of JBL? Perhaps a photo would help?


04-17-2010, 04:12 PM
Well I got the model number wrong is a 405G-1, was used in the LX500 and am sure others, but happened to have the tech sheet for the LX500.

But the construction is not as I assumed, managed to remove the JBL part/model sticker intact from the center of the magnet structure, and is not a tapped hole, but a center for machining.

looking around for the p/n on the speaker cups, seems they are for infinity mids, even though they match up with the 405G-1's, apparent y at some point they were to be used in an enclosure w/o an integral mid range isolation. Though the parts diagram for the LX500 does not show an attached backing cup on this mid, and does not show mid isolation chamber/baffle as part of the cab.

Sorry, has been a wild goose chase in the end, and at least now if future use requires mid backing cups, can mount these again much more cleanly.

Thanks again, sorry for making the assumption there were tapped holes under the stickers on these drivers.

Best Wishes To All