JBL L112 ?'s

[Zonker92]

Cool. The reading should be the same either way. And 5.7 (or what have you) is not a hard and fast number; voice coil resistance tends to vary from unit to unit. I would not be surprised to see a variance of 0.5 ohms or so between the same model drivers. Very rarely do I see matching DCRs.

The damping foam is almost certainly "dead," but a simple test is to pinch or compress it to see whether it springs back naturally, as new, or stays compressed, or simply disintegrates.

I don't think your questions are ignorant; I have posed many similar ones and it's a great way to learn!

This thread has advice on replacing similar but smaller foams:

http://audiokarma.org/forums/index....eeters-those-little-orange-foam-things.395419

 

[cloneofkane]

Cool. The reading should be the same either way. And 5.7 (or what have you) is not a hard and fast number; voice coil resistance tends to vary from unit to unit. I would not be surprised to see a variance of 0.5 ohms or so between the same model drivers. Very rarely do I see matching DCRs.

The damping foam is almost certainly "dead," but a simple test is to pinch or compress it to see whether it springs back naturally, as new, or stays compressed, or simply disintegrates.

I don't think your questions are ignorant; I have posed many similar ones and it's a great way to learn!

This thread has advice on replacing similar but smaller foams:

http://audiokarma.org/forums/index....eeters-those-little-orange-foam-things.395419

Great stuff right there -- thank you!

I am thinking it was rebuilt previously, because the foam still seems pretty spongy/springy still (destined to be a most-watched video, I'm sure):

That said, I think I will replace anyway. Is there any hard and fast rule to the height of the foam? Is it okay if the foam is tall enough that it has contact with the inside of the cone, or is that what you want -- to compress the foam down such that the inside of the cone is in constant contact?

 

[sx-70]

Is there new foam in the D8R044 kit?

http://www.audioheritage.org/vbulletin/showthread.php?29325-044Ti-questions-Help-needed
http://www.audioheritage.org/vbulle...uot-Others-quot&highlight=Foam+plug+mcmasters

 

[Zonker92]

I suspect the foams could use replacement; they look like they're on the way out, even if not totally gone. They might tear apart if you pinched them.

I think the height of the foam should be enough to press its edges against the dome, but I did not find an exact measurement on a quick search. I did find some photos.

 

[cloneofkane]

As sx-70 suggested, the kit came with a foam, both for under the cone. It came with an additional foam ring that I am guessing is just part of the packaging to secure the diaphragm, because there wasn't a like ring of foam when I disassembled the 044.

Also, there was a warning card that says centering this diaphragm requires test equipment and training. The cone fits into/onto the magnet very specifically and the screw holes are specific to both parts -- what centering are they referencing?

 

[cloneofkane]

Well, had the 044 assembled, hooked up and producing sound. Decided to make sure the wire connectors on the 044 connectors all the way, and I popped off one of the connectors.

Does this need to be soldered in place?

 

[cloneofkane]

I was able to solder the connector on securely to the diaphram and get a nice 6.9 reading on the DMM. In the meantime, I found an additional complete and nice condition 044, so now I have a back up that I hope I never need.

Question: this 044ti diaphragm is not registering any reading on the DMM. Do folks rebuild these and/or would this be of use to anyone?