Mordaunt Short Avant 309i subwoofer set-up

Question

I suspect that this is not a simple answer but before I purchase I'd like to know the factsMy home cinema system uses 2 MS 903i rear surrounds, 2 904i floorstanders and the 905i centre speaker. I love the speakers. I now want to add the MS 309i sub woofer which I am assuming should fit seamlessly.However unlike the speakers the sub has to be configured, using the various different settings.1. Volume2. Notch filter3. Frequency4. PhaseIn simple terms - how do I do it?