I've seen some graphs that show the results of what you are contemplating, on sites that compare corner traps to corner wedges. I am amazed at how effective the trap you are contemplating is. It works quite well... until you get down below 125Hz. Even 6" fiberglass fails to make a big difference in the lowest octave. Since I need a lot of help below 60Hz, I am building a wedge. In fact, I have the first empty wedge up and completed... I just need to buy the fiberglass to fill it with. I am quite excited!