[octatonic]

Hi all,

looking for some feedback from people who know what is what regarding DIY basstrap construction.

I've built 4 traps.
All are 1200mm x 600mm.
2 are 200mm deep
2 are 125mm deep

All of them have 80mm of steinwolle (rockwool in english) which is 2 x 40mm units.
I've covered them in a stretchy fabric which is on a frame that sits inside the main box.

My main questions are - do I need to have a large air gap behind the rockwool?
The traps that are 125mm deep only have about 15mm of air.
The 200mm traps are quite bulky and now I need to make more.

Can I get away with having them 125mm deep with 80mm of rockwool?
Is there anything crucial I am missing here?

Pic enclosed