A:
They register as 6 oHms. I think with the crossovers the oHms drop.
Depending on your amplifying source, they should do well on 8 or 4 oHms.
If your source is restricted to 4, your volume level will lower than expected.
If your source is 8, the volume will be higher than expected,and will generate more heat.
You should be fine.
Hope this helps.