I have found that hanging shoe boxes on the walls is a better way for achieving acoustical bliss. However, you have to strategically place shoes in some boxes while leaving others empty. It's a trial an error process so you might have to switch between Nike and Adidas. IMO, any other brand provides diminishing returns. Finally, tying the laces in a very specific configuration makes a huge difference -- in my room it felt as if the sound was looping around my head and shooting towards the ceiling. And yeah, if you're going to try a rug make sure you wipe the soles first, otherwise the eleventh wave bouncing off the third reflection point might get stuck in the first shoe, and we know how undesirable that is.
