I've done countless refoam jobs, also on the CX range, a couple of pairs in currently.

A certain amount of skill and practice is needed to get it right
and, considering the repair cost, I wouldn't recommend anyone
to have a go themselves. The risk of ruining something or getting
it out of alignment could do permanent damage to the woofer and
it could end up a total waste of money and time instead of a cheap solution.
If you don't carefully shim up the coil and, in some extreme cases,
also the spider, you won't get a good solution.

Done correctly, the woofers are practically returned
to a "like new" status, also with the right frequency range etc.
The coil and impedance aren't changed so no worries at all regarding
the electric specs.
The woofers will need a certain amount of "playing-in" again to
losen up and sound right - not unlike when they were actually new.
Obviously, I cannot tell you what other people use but the surrounds I use for the repairs are extremely close to the originals - when they were new that is.

Martin

Please note these 'new' replacement drivers are also 12 or more years old. They have been stocked on the shelves, so the foam rot didn't go that fast, but even in stock the foam rots! It's best to replace the rotten rings with new rings that have been pressed in recent times so they will last longer. It's also possible to replace these rings with rubber ones - results are very good if you you use the right (very rhin, low weight) rings. If you replace your units with the ones by B&O you may suffer foam rot again in a few years.

Did B&O tell you this or is it an assumption rather than a fact ??

Because to me it sounds very unlikely B&O (or any manufacturer) stocking up spares in advance for years, not knowing how much demand there is for it.

I've ordered many drivers also for (MX) tv's in the recent past and never had even the slightest impression it was 'old stuff', more logical would be that if they run out of stock they just have them made again from their supplier (say 500 poeces or so) as happened a few years ago with the battery lid for the 'chocolate bar' remote: it was out of stock but apparently still so much demand they had them made again.

If a manufacturer has to stock up spares for all their products for their lifespan they'd be broke and need enormous warehouses :)

(imagine the pile of picture tubes for Avants.......).