Does my Purple® Mattress have to be split in order for the Ascent Adjustable Base to work correctly? The Ascent Adjustable Base comes as a Split-King and works well with a King mattress OR two Twin XL mattresses. Related articles Do you have a bunkie board option? What is a Split King? Should I wait to sleep on my Purple® Mattress after unrolling it? Does Purple sell mattress toppers? Does the mattress stay in place as the PowerBase is adjusted?