If you want to reduce noise from ground loop potentials, just make sure all connected components are on the same circuit and properly polarized. If you mix video and audio, be careful because a lot of noise can come over the CATV cable. In that case you may need an isolation transformer. Aragon used to make one which I think consisted of two 75ohm to 300ohm transformers piggybacked at the 300ohm side. Also make sure your CATV comes from the street to a grounding block, and that the grounding block is connected to the ground of the main service panel. If you have a roof antenna, the pole gets grounded to an earth driven rod and the signal cable from the antenna itself goes to a grounding block, which is also connected back to the main service panel ground. One ground plane means least possibility for a ground loop potential to develop.
If possible, try to run your dedicated line away from noisy circuits or equipment such as motors that could generate noise which could be broadcast into your line. Shielded cable such as Greenfield may be of use as it has 3 conductors (black-white-green) in a metal jacket. The metal jacket would serve as the shield. BX cable only consists of 2 wire (black-white) with the metal jacket serving as the ground and shield. In a noisy environment, I would prefer a ground separated from the shield, such as Greenfield cable.
Surges and pops can also be captured at the service panel by installing a system surge suppressor on the main panel. These help capture noise from the street as well as noise generated within the house from different circuits, such as when a noisy bathroom blower fan or refrigerator switches on or off. In this scenario, the noise travels back to the circuit panel where it is captured before it can travel down another circuit to your equipment. In addition, one of those "Monster Cable" type Power Centers can provide individual filtration and surge suppression at each outlet minimizing component to component noise coming across the power line. Another reason to invest in one of those "Monster" type devices is because they usually have a pretty decent warranty for anything plugged in and protected by them. I would not recommend using a computer styled UPS as I have found them to generate noise and actually degrade the overall sound.
