sub setup question

a friend of mine is setting up a 2.1ch system consisitng of nad d7050 integrated, hsu vtf mkii sub and wharfedale 10.1 speakers. he asked whether he's best served using the amp or the sub for bass management and optimal crossover settings--can you experts chime in?
I don't think he has a choice.

Unless I'm mistaken, the NAD only outputs a full range line level audio signal. The HSU x-over function will be necessary to route the frequencies appropriately. He may have a choice whether or not to run the Wharfedales full-range (I'm unsure if the HSU outputs a crossed high pass signal to return to the amp for feeding the Wharfedales), but - either way - the bass management will be performed at the sub.

He may also connect at speaker level, but - again - the HSU will provide the bass management there.

BTW, please cheerfully ignore this post if I've misunderstood the question or don't have the NAD's capabilities right.
marty, the nad's a hi-falutin digital amp which provides options for running either the sub full range or at different crossover frequencies--i would assume there's a crossover bypass switch on the hsu which one would use if he was setting the crossover at the amp, but i'm a dullard at such complexities. assuming the foregoing (including the dullard part), would it preferable to set the crossover at the amp or the sub?

I just checked out the NAD website and learned that there are indeed bass management functions available "through" the d7050. I also learned that the reason I didn't think that was the case is because those features aren't found on the amp, itself. They're found in an app that you download to (and control with) an iPhone. That said, I ain't got a clue as to how good they are/are not.