question about center channel when downfold from 5.1 to stereo

[vudoo]

Just completed another surround 5.1 mixes for a documentary. I need to deliver a stereo version and I'm just curious by how much you guys usually attenuates the center channel when folding down to stereo. I usually pull it down by -3db, but lately i find myself just leaving it as is ( LsRs always gets -3 Db and LFE - 9 db or none ).
Also when i use the Waves Mixdown plug-in ( Stereo foldown ITU setting ), i find everything seems louder especially dialog. Anyone knows what's the specs for ITU foldown and is this the norm for most home DVD desktop player ?? Thanks

[pneyrinck]

The ITU standard and the default down mix that a DVD Dolby Digital decoder does is to mix the C channel to the L and R channels with -3 dB gain. That results in the L and R speakers producing equal power as would a single C speaker. Equal power means that the perceived loudness should be equivalent. So, something is wrong if you are hearing the down mix dialog as louder.