Monitor cables

So I have always used regular old instrument cables to go from my Line 6 TonePort to my monitors. For a while now, the left cable has been constantly creating a low volume buzzing sound that gets a bit annoying. I'm trying to understand what the right cables to use for monitors are and I am a little confused. Are regular 1/4 inch instrument cables okay? What kind of cable do I need to get to get rid of this buzz? Any help would be appreciated!

Line 6 toneports dont have balanced outputs (afaik), so there is not really a benefit in using balanced cables. what I have experienced with toneports is that the jacks on the toneport itself go bad and cause the hum. the jacks are not really mounted to the chassis but to the circuitboard. that is in most of the times really unfortunately.

I'm an equal opportunity monitor-ist. One pair powered one pair passive - the powered are on XLR Balanced connections, the unpowered ones are fed by an amp with PHONO connections! Neither of them hum. Probably because I keep the lyric sheet in front of them. (sorry! :D )

Don't worry about it! It's really just that I'm old, and "back in my day" decent amplifiers were too big and heavy and hot to fit inside an affordable near field monitor, so we all had passive speakers running from a seperate amp, which would be a somewhat different cabling scenario. Technology has advanced. I actually have no first-hand experience with any self-powered studio monitors, but I understand that most of them work well. It's not as though you'll be sacrificing quality for convenience, though I guess I haven't checked relative pricing on comparable systems - self-powered vs passive + amp.