Question regarding QD 23 Construction plans-Acoustics Forum-Acoustic Fields Forum

Hi! I purchased your building plans and wan´t to build some QD23 but first I have some questions:

1. Can you point me to a resource or search terms in order to learn what kind and how much of acoustic treatment my room needs?
2. Regarding the QD-23 what if wan´t to build a larget unit? could this affect perfomance? or will just be a larger surface? Wells will be the same depth and width, just more long.
3. Do the wells need to be filled with something? how should I install the well´s covers, are they supported by something? or just glued to the sides?