Simple. Whatever your ears tell you sounds best. Every room is different, not least the speaker placement and listener position, and all this can have a dramatic effect on the sound.

If you wish, you can run Trueplay. That will attempt to compensate for the above, to arrive at a more ‘standard’ response profile.

Just as @ratty says. Go with what you like. 

If you want something to start you off with your stereo One pair (I’m assuming this) then try +3 Treble, -2 Bass and Loudness On. I use these with my Play 1 stereo pairs, where they are somewhat close to a wall, and I find that it helps give the sound a bit more substance as well as bringing out percussion and vocals.

My settings are at the centre for all, after doing Trueplay. That is as good a starting point as any other for any further tweaking, I suggest.