What power conditioner will help in my situation?

Yes, I agree that trying a long extension cord running to a different room should be the first thing that you should do, at least as an experiment.

But can you clarify what you mean when you say "when I change the fan speed there is a low frequency hum when I turn the fan speed from low to medium etc." Does that mean that the hum occurs only while you are changing the fan speed, and perhaps for a second or so afterwards? Or does it mean that the hum is always present, but is affected in some manner by a change of fan speed? Or does it mean that the hum is not present in "low," but is present at the faster settings?

Regards,
-- Al

To clarify, its not a constant hum, only when I change the fan speed I can hear a low frequency thump in the speaker.

One of the reasons I asked for clarification of that point is that I don't think we can be totally certain that the means by which the fan or its speed controller is affecting the system is via the power wiring. I wouldn't rule out the possibility that the effect could be occurring as a result of airborne interference (RFI), in which case a dedicated line, as well as power conditioning or regeneration, would not resolve the problem. RFI would of course not be at frequencies that are low enough to be audible, but I don't think we can rule out the possibility that it might cause some circuit in the system to produce a low frequency thump.

So before going to the trouble of having a dedicated line installed, I would repeat the suggestion that was made early in the thread to try running a long extension cord to another room. If that solves the problem, then yes, a dedicated line probably would also.

Regards,
-- Al