These have stopped the flutter echo in my mixing room, make sure you follow the instructions and place them where they should be placed, they have done a perfect job for me, they are very good at stopping flutter echo, and at the same time keeping the high and mid-frequencies without absorbing too much.
The bass traps in this set. I must say they made a difference, but I think you will need some extra dedicated base trapping alongside these, all in all really good tiles.