The yellow (tan) foam sure looks original but looking at the glue on the underside of the cone makes me think of Elmer's white glue. Also, if it is original, it's in remarkably good condition considering a comparison to the tweeter foam, not to mention that that speaker is wired in series with the 12" and the excursion due to the bass notes would surely have caused separation and rupture. Look at the tweeter and it's only handling the highs above 3000hz or 5000hz. I might add here that the capacitor for the tweeter is, in all probability still good as it's the oil filled type. However, if you feel better about it, change it as replacement polypropylenes are quite inexpensive.
Regarding the tweeter, the centering device. I hope my web page on that was clear enough. If not, PM me and I'll add to that page. When I wrote that page, I tried to make it easy for a novice to understand but some of that may have slipped through the infamous cracks. Once the centering device is removed, you could desolder the braided wires from the connecting strip. Use a small alligator clip as a heat sink between the terminal and the cone; you don't want to damage the solder joint at the cone. Besides, the coil wire is aluminum and can't be soldered by conventional means. Sma alligator clips, about an inch long are light weight. This will allow complete removal of the cone and application of the annulus will be much easier. When replacing the assembly, shim the coil before replacing the centering device. This will stabilise the cone and make it easier to affix the annulus to the basket.
Once the cone is removed, use a compressed air can to clean the gap; hold the speaker upside down and away from your eyes (use goggles). The foam disk has fragmented and the pieces, small as they are, will be all over the inside of the gap and inner magnet assembly.
If the 10" unit works ok, it might be better to leave well enough alone; it's up to you. If you do replace the foam, remove the dust cap and shim the coil with the spider flat. Oh, does it or the 12" have a corrugated cloth spider or the older phenolic type? If the phenolic type and if the coil isn't rubbing, then the screws holding the spider haven't been tampered with. Shimming should still be done to prevent the coil from touching the pole piece or the inner edge of the top plate which could damage it as the cone will tilt as you apply the foam. Plus, it will stabilize the cone while the foam is applied. Oh, if you have to remove the cone and if it has a phenolic spider, DON'T lose the screw and/or nuts. They look like SAE (Society of Automotive Engineers) but are BSW, (British Standard Whitworth) and are not easily found. In fact, I doubt the Brits are still using BSW. the same applies to the screw in the center of the tweeter pole piece.
The cloth surround on the 12" looks ok and probably is. If you would, take some front view piccies of the speakers also as well as the spiders on the two larger units.
Gee, I know that so much of this detail isn't in my web pages. Gonna have to fix that. Your questions have inspired me. Thank You.
Robert
