Remember if you can ..the thicker the better ...don’t skimp on thickness and stay away from thin panels such as 1 to 2” they are basically worthless.
Doubting Sound Treatment ?
3 years ago I purchased an 11 piece Kit from a reputable company. I noticed improvements, but wasn’t instantly blown away. Now 3 years later I took it all down for a home move. Bass definition noticeably less. Instrument placement less good. Overall coherence less. Not a as intimate. Far less enjoyable, simply put. If your on the fence, get past it. Better improvements with the treatment than most of us hope for when we change Preamp, Amp, or Speakers. Doubt no more !
Cheers !
Cheers !