wtf are you talking about loudcrown.
if you want to put a 8ohm speaker on channel 1, a 2ohm speaker on channel 2, a 4ohm speaker on channel 3 and a 16ohm speaker on channel 4, they will ALL run at RMS power. the amp may get a bit warmer running all four channels at 2 ohm, but yes. yes they can do it.
thats why they say "2 ohm stable" - that means, anything 2ohm or more is AOK.
so in lamens terms, yes, you can run two channesl at 4 and two channels at 2. i had my memphis belle running that way for nigh on a year.