Avoid resonances in plasterboard with absorber??

[hugo_inside]

As you can read in this thread: http://www.johnlsayers.com/phpBB2/viewtopic.php?t=4299 CYEAZEL advice me to add 2 layers of drywall to avoid resonances...

but in the control room:



I will build a bass trap in the rear wall, isolation wall is made by
200 mm concrete block with sand/ 50mm airgap/ 40 mm rockwool 70 kg/m3 / 1x 15 mm sheetrock.

If I'll put the that bass trap in this wall, there still will be resonances on this layer of drywall??

[hugo_inside]

the next week we start to doble the layers of drywall in the recording room, but it's necessary to do this in the control room too??