Impedance Question

I have an Onix SP3 MKII integrated tube amp with 4 and 8 ohm taps. I will be getting a pair of Wharfedale Diamond 9.6s this afternoon and they have a nominal impedance of 6 ohms. So the question is which taps do I used in my amp?
whatever sounds the best

usually whichever is the loudest, esp. in the bass

if it really is a tossup, the 4 ohm tap may provide firmer
bass (if you are using a tube amp)

frequently the mids and highs are better with the 8 ohm tap.

you will figure it out.

it ain't gonna hurt the amp or speakers either way.
That's all I was wondering. Thank you.