Just so our terminology is straight, noise is usually high frequency stuff like you hear between stations on AM radios. Then you have hum, usually 60 and 120 Hz. Balanced connections will tend to cancel out hum picked up by the cables. They may cancel some noise, but the big gain is for hum. The interesting thing is that most balanced connections actually have a bit higher noise than the best single ended connections, unless you use transformers, because of double the active devices.
IMO, no home system should have a problem with single ended connections unless there's an unusual interference source present, or unless there's some fault with the equipment. Any decent tech should be able to service Soundcraftsman equipment.
What kind of hum/noise problem have you got and what sort of stuff have you got hooked up at what distances?