can i use a 8ohm subwoofer with a 6ohm speaker?

[29man]

i have a 80w rms 6ohm per channel amp and 6ohm 80w speakers. can i add a 40w 8ohm subwoofer to one of the channels or would it be a bad thing? the subwoofer has no active amp.

 

[ooxj2000]

they say your not suppose 2 mix ohms, i blew a amp doing this