Audio Systems: Camper speaker problem, dc power supply, audio decks

Question
My wife and I recently purchased a used 35 ft camper which is permanently placed on a lot in a campground.  The site has 120 volt AC running to it.  The camper also has a converter in it that transforms the AC to DC for some of the lights and other items in the camper that run on DC power.  The problem is that every time we turn on one of these DC devices (lights for example) we get a pop/hum noise that comes through the speakers that are throughout the camper.  Is there anything we can do to keep this from happening?

Answer
the dc power supply in the camper doesn't have enough filtration so some AC is still coming through the dc.
Depending on how many amps the sound system draws you may be able to power it with a better power supply.  If the camper has a standard car audio deck and no external amplifiers then it only probably draws about 10 amps which is easy.  if there are amps or its a unit that's different than standard car audio decks then it may be more complicated.
assuming its a standard deck, and you don't mind pulling it out and doing some creative wiring we can fix this.  the cleanest DC power is from a PC power supply.  you can get these cheap at www.tigerdirect.com for like 50 bucks.  (I'll pick one out if this sounds like something you want to try.)

if you want to just wire it permanently then just disconnect the wires and hook up the power supply.  if you plan on driving the camper sometime or often you can put a switch on it so that you can easily flip the switch to AC power or battery power.
Again, let me know if this sounds like something you want/can do and I'll give you the details of how exactly.