Control Room 2.0

After working now for 2 years in my control room, I want to update it to Version 2.0. There for I want to build a speaker wall, but no mounted speakers. I build mid-range absobers, hanging on the ceiling. In the back there is a bookshelf for records and vinyls working as diffusor. Abovem, the yellow blocks, there are rockwool blocky, cause ther was space over the stairway. I want to build slat resonators as speaker wall, but dont know how to start calculating.

generally speaking, you want broadband treatments unless you find you have a specific problem. check John's corner wall cabinets as a start.

I found this plan http://www.johnlsayers.com/phpBB2/viewtopic.php?t=8836 I am trying to convert it for my room, the extensions are nearly exactly the same. Where can I find, whats behind the cloths? Is it just rockwoll or hanging absorbers?

behind the slats will be an open weave cloth and then 703 insulation (or if its out of budget) pink insulation. the insulation will sit away from the slats - perhaps half-way and also on the wall side. the compartments are divided up to improve efficiency at the design frequencies. in the front bass traps you'd probably put in some hanging broadband absorbers - below the speaker (shorter ones) and behind it (taller ones).

The thing I dont understand is, why there is (under the loudspeaker) only a compartemnt with small depth. Why they dont use the whole depth of the compartement for the basstrap just covered with cloth? Is it for being reflective? I understand that in the departement behind and under the LS there shloub be hangers like in SAE reference material, isnt it?