Laminate Flooring Underlay

[Blokeofkent]

Hi,
I have 2 adjoining rooms that I would like to lay laminate in, so that it runs level throughout. One is wooden boarded which stands about 10mm proud of the adjoining concrete floor. What would be the best solution to bringing these 2 floors level? I won't be able to screed the floor so have been looking at various underlay options.
Hope you can help,
Many thanks.

 

[ree]

If you can lay laminate on the concrete floor how come you cant lay a SLC?

All finish work relies on sound prep work. Building up with an underlay wouldn't be my idea of a sound backing surface.