DIY corner bass traps

hi everybody I'm trying to built some basic bass traps for corners I'm using some rigid rockwool panels 80kg/m3 I'm putting them flat in front of the corner (so they become the third side of the "triangle", the hypotenuse) covering the entire height of the room, from floor to ceiling. my question is: do I leave the space of the corner behind these panels empty (the wall is build with plasterboard) or is better that I cut rockwool 50kg/m3 triangles and put them in colums for better bass trapping???? hoping everything is clear, thank you and sorry for my english Marco

Stacking triangles behind is the best advice - so called superchunks, otherwise you can just fill the space with rockwool or fiberglass batting - but not tightly packed.

I'm using some rigid rockwool panels 80kg/m3

That is way too dense for bass traps! Might be fine for treating the high end, but not for bass traps. Look for something about half that density, or even less. - Stuart -

hi soundman I tried to study the bass traps subject these days studying means that I read all I can find.... a lot of manuals, tutorials & post suggest to use owens corning 703... here I have rockwool 5cm and 50kg/m3 and some days ago I decided to use that material but many authors say that if I choose a different product, like rockwool, I need to buy a more dense panel to match the 703 acustic properties! May I misunderstood? Another example is ethan winer: for corner bass traps he suggests the 705 (more than 90kg/m3) So isn't a more rigid rockwool panel better for low frequencies absorption??? thank you

The superchunks or batting would normally be less dense, but the front panel can be made of the denser rigid boards - covered of course with a fabric or plastic film and fabric. I'm assuming the panels in question are not too thick.

thanks a lot to everybody!