I think we're in for double eliminations for at least the next 2 weeks so that it'll go something like this:
Week 1 - 2 acts go, 11 remaining
Week 2 - 2 acts go, 9 remaining
Week 3 - 2 acts go, 7 remaining
Week 4 - 2 acts go, 5 remaining
Week 5 - 1 act goes, 4 remaining
Week 6: Semi Final - 1 act goes, 3 remain
Week 7: Final
They could always swap them around and have only 1 go in Week 4 then 2 in Week 5 or 6 maybe?