wrote in message

The problem is that while both Alnico and ceramic hard magnet
materials are capable of storing large amounts of magnet
energy permanently, they have a limit: the flux density the
can store is limited.

I thought that the magnetic force in all magnets eventually diminishes,
although probably so little that the performance of a loudspeaker would not
be affected during a listener's lifetime.

Could you perhaps shed some light on this matter?

Thanks in advance.