Hi all - Im looking to build a one piece diffuser. Ive looked a lot into diffusers and i want a skyline diffuser. The calculations and ect are so confusing for me and don't understand the calculations at all.

I want my diffuser to be 110cm X 65cm and to cover the 750hz - 4/5khz range or near.
Could you please help me with a diffuser grid for this please as I have no idea on it

Thank you very much