[lojban-beginners] Alveolar ¿ Coronal

[Tasci <lojban@synx.dyndns.org>]

I was trying to learn more about the pronunciation of c and s in lojban.
I was under the impression that c was the English sh, but they say
that's {tc} in the handbook.  It says here:
http://www.lojban.org/tiki/tiki-download_wiki_attachment.php?attId=195&page=The+Lojban+Reference+Grammar
that c is an "unvoiced coronal
sibilant," and that s is an "unvoiced alveolar sibilant," but wikipedia
here:
http://en.wikipedia.org/wiki/Coronal_consonant
says pretty clearly that Alveolar is a subset of Coronal.  That would
mean s is an unvoiced coronal sibilant too.  By "unvoiced
coronal sibilant" did they mean "unvoiced dental frictative" as
wikipedia defines it?  That would mean c is the English 'th' as in
'thing', and s the expected sound for my native tongue.  Or is c 
postalveolar, like the English 'sh' as in 'ship'?