Is a sub on a different circuit often a problem?

I'm in the process of rearranging my HT system in anticipation of eventually getting a flat panel TV that I plan on mounting on the wall. So I'm wiring new A/V connections to the new site of the A/V equipment.

I plan on moving the sub to a different corner than where it is now. As of currently, I don't have an outlet to the dedicated 20A home theater circuit in that corner for the sub to use. I could always wire one, but I first wanted to get a sense from people here if they actually have ground loop / hum problems with a sub on a different circuit or not before I take the time to do it.

Thanks,

Michael