Etherium Sculptor X

[Phoenix Ignition]

Simple questions.

If I have 2 Etherium Sculptors in play can I cast a Chalice of the Void for 1 charge counter (so paying 1 for each X) without paying any actual mana? If I have 2 Etherium Sculptors out can I cast a Chalice for 0?

My guess is that you first declare what you are casting the spell for, then the Sculptors effects bring the cost down by 2?

Also, for Sigil of Destinction, if I have Etherium Sculptor out and 1 mana up, can I cast the Sigil for 2 by only paying 1 mana?

Last question, if I have Chalice of the Void @0, and a Sculptor in play, can I cast an Engineered Explosives for 0 charge counters (by pretending to pay 1 or whatever with the Sculptor)?

Thanks

EDIT:
Thanks, just needed to know for sure before I go to the PTQ Sunday

[luma]

Yes to each case. You always choose the value for X first, then apply any cost reductions (sculptors). They don't change converted mana cost, so EE with X=1 will have CMC 1 even if your sculptor makes it cost 0. They also don't change the value of X, so if you play Sigil with X=2, sculptor makes it cost 1 but it comes into play with 2 counters.

[Anusien]

Think about it this way: pick the value of X you want, then apply cost reducers. Don't look at the number of counters you want it to have and work backwards.