speaker wiring question.

[Moses 876]

ok guys...im currently looking into some amps...but i have a question i need answered.

so i have a total of 2 pairs of speakers. one pair is 70w&4ohms and the other is 85w&8ohms.

so lets call them speakers a,b (70w/4ohms) and c,d (85w/8ohms).

first of all can i mix the different impedances? some research has suggested thats its possible.

second, if i wire speaker A & C in series, parallel to B&D in series, based on calculations that would equal to 6 ohms resistance total and roughly 83.3w for C&D and 41.6w for A&B... correct? any harm possible from this? anything i need to know? also should i use a higher wattage amp? like 300? seeing as the speakers would be "underpowered" and the amp possibly running at its limit? (right?)

i got confused at a point and thought running this setup it could actually be 12 ohms. could someone clarify for me?

i used this calculator...but want to be certain.

[Moses 876]

just noticed i probably posted in the wrong section...could the mods please move it to the correct one.