I think I have sinned. Absolution anyone?

[Syncamorea]

Bass trap the back corners. The height = width will be a problem. I'd be tempted to build some soffits at all of the wall/ceiling intersections. You can add slats to the front wall absorber and you can modify those to lower the minimum frequency absorbed.

[syncussion]

Well.. I personally strongly prefer the lighter wool you have now.
If you can make it ten times as thick it'll work better than denser wool. It'll really sound as if nothing is there when you talk against it etc, something denser wool won't give you.

But are you sure the GFR is only 5000 Pa.s/m2? They look a bit sturdy for this in the pics. Mine are extremely fluffy.

[ACreature]

Thanks for your input guys. Syncussion: At the front, how does one add modified slats for more bass absorption? Any links? I thought slats or wood panels are to liven? Soffits too complicated for rented space. There is a problem with trapping the rear left corner to ceiling as that is my exhaust vent. What would you do there?
To all: Actually that whole door area at the rear is one large drywall bass trap (resonant at what I do not know yet), it is 2 leaf connected on both sides. That alcove walling also seems to me a problem at the rear, will probably interfere with the 2d diffuser I want to put there above that couch. The front treatment is 5 cm plain kraft-backed rockwool roll 22kg/m3 nominal density (pretty sure that is roughly the GFR I stated). At those 2 vertical white strips is where the rolls double up to give 10cm (really about 9cm), but it is all attached to the wall. No way can I lose so much real estate adding 10 times the amount, would much prefer either add something live to counteract the effect or to deaden but with thinner higher density and an air gap. But what is the best shot in the dark for a trouble free starting point? Members I respect most such as DanDan seem to advocate more absorption

Gregory