Question for owners of the Yamaha HTR6160 (Or RX-V663)

[azereus]

If the speakers being used with this receiver all have a normal impedance of 8ohms, is there any tweaking required on the receiver or is it "plug and play" (for lack of better phrase)?

I noticed in the manual there's a how to section for setting the speaker impedance but it doesn't say what the default is.

I may be way off here or have said something silly, but i'm learning as i go...

Thanks guys