Royalties earned are net receipts multiplied by the royalty rate. The advance recoups from earned royalties, so the unrecouped balance is the advance minus royalties earned, and nothing is payable to the artist until that balance reaches zero. Time to recoup divides the remaining balance by expected monthly royalty earnings.
With two releases, the cross-collateralisation toggle switches between one pooled balance (surplus on either release pays down the pool) and fully separate balances (each release pays out its own surplus). Same sales, same rates — the payable amount can differ by the full surplus of the recouped release, which is why this single contract flag matters so much. The worked examples in our guide to complex royalty contracts go deeper on recoupment pools, reserves, and escalations.