Apple Logic Pro /LogicExpress Discussion

Hey again -

I am pretty much forced to run my cables to my monitors along with my 
inputs to the digi001 along one wall in parallel, and I have a hum in 
my monitors as a result.  (the cables are also not the best probably, 
so that may be an additional consideration.)  the distance is 20 feet 
max, probably closer to 15.

thinking of dispatching with this hum once and for all as a birthday 
present to myself.  any advice on the best (and cheapest) way to do so? 
  are there cables that are well-shielded enough to remain silent under 
these conditions, or do I need some kind of hum-cancelling solution?

Thanks -

Michael