I'm restoring a pair of Magnavox 6" speakers in my 1962 Pye portable radio gram. The 2" discs glued across the inner apex of the cones have crumbled - some larvae mummified in their cocoons are possible culprits.

The remnants look like plastic foam, but I would have expected something stiffer that might project sound from the centre?

What do people use to replace missing centrepieces like that? The main cones are in good order.

Maven

I assume you mean the disc over the voice coil? These are usually made of thin felt, which does crumble with age and excessive heat and the occasional hungry insect. They are there just to keep grit away from the magnet. Strangely enough, some models have speakers that I have never seen these covers installed on, the 1930s Radiolettes being one of them.

Best to replace with what is there. Felt was common, Newer speakers often have solid Aluminium but the magnets have higher flux density.

You can change the resonance (depending on size) by installing a solid centre (felt breathes).

Marc

Felt it shall be. Heart-felt thanks ;)

Maven

Good move:

If you are worried about it being eaten again? Perhaps follow what the Egyptians did with Mummy wrap:-- Pad in some solution from from Tobacco, it kills bugs (Nicotine (cigarette butts) is a fantastic snail killer). If you want it to last as longer add Cocaine as that is the stabiliser for the Nicotine.

Big question!.... How did they work that out?

Marc

I'll remember to infuse the pads with tobacco when I am preparing to move to the next life and take the radiogram with me, just in case there are some undiscovered 78s in the place where I go next. Infinity offers plenty of time to enjoy music, if you are properly equipped.

Maven