I have a wireless network at home, but it's not giving me the expected signal although the distance isn't that long.

Several questions need to be answered :

1- What is the best placement for the router ? For convenience I have it on top of a subwoofer, so I thought that might cause interference, but I wanna know if it REALLY does.

2- How can I change the encryption settings or tweak the router to give a longer range ? I am using WPA2-PSK with AES encryption, and broadcasting on channel 11. I've read that changing the RTS threshold (reducing it) will give a longer range, but I don't know if it will cause any problems.
I also recently enabled "Xpress Technology" which should make it better.

ANY info or tips are appreciated...