Mixing speakers with different impedance

[FSI]

Hi
I have a 5.1 setup with speakers rated at 6 ohms
1.  If i replace the main speakers with 8 ohm speakers will it cause any problems?
2.  If i introduce a poweramp to power the 8 ohm main speakers will it cause any problems?

Thanks

 

[bbe22]

 

[pwatts]

 

[PapaH]

 

[moloels]

 

[pwatts]

 

[moloels]

 

[FSI]

 

[moloels]

 

[FSI]

 

[grumpybear]

 

[moloels]

 

[pwatts]

 

[Neil]

 

[bbe22]

 

[pwatts]

 

[Neil]

 

[Ampdog]