Hum in speakers

With the Amps just plugged into the speakers the hum is still there

Is the preamp disconnected or just turned off? If off disconnect the preamp at the amp end. Also is the hum coming out of both speakers? Does the hum occur all the time? Which amps do you have? Some amps are known to have a low level hum.

Do you have a dimmer switch on the same circuit as your system?

Hum comes out of both speakers it is all the time they are Sierra audio Denali mono blocks 

There is a dimmer switch which controls a ceiling fan

Dimmers are notorious in terms of dirtying up AC. Do you have a hum with the dimmer switch completely off (or, conversely, all the way up)? If not, then it's the dimmer switch. If you still have a hum, troubleshoot as the posts above advise and try to isolate which component may be the source.

You can have an electric company in your area run a dedicated line from your wall outlet to your circuit breaker for fairly cheap. That way you amps will draw power meant for them and for them only.