Salut Faiyaz,
 FA> I have a couple of cassette tapes that are beggining to sound really
 FA> dull.  All of the highs have been muffled and the lows have been
 FA> slurred.  I guess its because of their old age.  Is there anything I can
 FA> do to reverse its progress and keep it from happening again?
Nothing, as far as I know.
Everyone that still has old analog material is busy archiving it digitally on 
some kind of reliable storage media.
But there have been some records recently released that claim to be remasters 
of some fairly old material. If your tapes are worth a lot, you might try to 
let them restaurate by a pro.
bye ....
         Joe
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