It all depends upon the other surfaces (walls, ceiling, etc.) that you have. If they are reflective, I would keep the wool rug in place....
I've read a fair bit on room acoustics and balance can be one key. So I might agree with RW, what are your other five major surfaces like in terms of absorption/reflection?
But Zd542 asks the most basic question - do you have problems now or are you just restless to change something?
One point I've read from several sources, wool is one of the best absorption materials. It is better than most any synthetic. So your berber with thick pad would seem to be a good choice as part of the desired absorption percentage.
I stuck "vibra pods" under my speakers on wood floors and they sound amazing...this was after decades of spikes, and it seems that some high end speakers come with what they call "decoupling" dampers so there could be a trend away from spikes...for room treatment you can also try buying thousands of pods and stick them all over your walls and ceilings, but I find that hurling large amounts of freshly cooked pasta against the walls works well, although you have to keep at it as it dries out and falls off.
Well, if you cook the pasta al dante, of course its going to fall off. And you're probably using spaghetti, or something else really smooth. If this was for dinner, that's one thing. But for audio, you need to get a rough pasta like rigatoni, and over cook it. That way you have more surface area to work with from the ridges in the noodles and over cooking it means more drying time, which allows for better bonding.
I removed four flat 2' X 4' absorption panels yesterday, and liked the results. The sound opened up a bit, and had more emotion. SOME recordings were slightly dry sounding with the panels in place. What I hope to accomplish is more natural sound, which a room being too dead can hinder. Room is 23 X 12 w/ 8ft ceilings, speakers set up on 12' (short) wall.
Sheet rock walls and I have two 4ft X 4ft older RPG-like wood diffusion panels stacked on one another in back/between speakers. Check out my photos on my system page (-:
Another quick detail. All windows are covered with curtains, but some also have thin ply with egg crate foam stuff glued to it. This is true with the rear windows seen in my photo.
Those absorption panels you see kitty cornered are still there. The four panels I removed yesterday are identical, but were on the side walls. In back of my listening position are several Ikea Expdedit racks full of records. I may take a few baby steps and remove the foam from the ply I have tacked to the window frame. Needless to say, this is a dedicated room(-:
before you do that.......just take all your wires and cables off the floor/rug, separate them as much as you can. try not to run them all in the same socket. use an extension cord to put some of the non essentials in another outlet. make sure you run the power amp and pre amp directly into the wall. don't use a strip for those.... and let me know what happens........