I have a Sirius radio hooked up to my home stereo in the livingroom and I would like to have a small speaker in my fish room playing the same music so I can hear it over all the running water. Even at 140 decibels in the house I can't hear anything but the bass in the fish room with the door closed.

Is there a way to have a remotely placed speaker in the fish room without running wires around the house? I would like the speaker to plug into the wall for power though. The last thing I need is to be replacing batteries in it (like the Bluetooth speakers). A great option would be the ability to switch the speaker off easily without turning off the system in the livingroom.
Any ideas?