adding foam in the cd1k was spot-on! 5mm gave muddy bass and wonky mids...6.5 is spot-on, everything's perfect so far 
and I haven't covered the whole cups inner surface, to still keep some resonances
so dampening = yes! but not entirely!

and I haven't covered the whole cups inner surface, to still keep some resonances

so dampening = yes! but not entirely!





