As far as the noise filter goes, any noise can be eliminated or supressed with the right kind of noise filter. The problem is that they getto be kind of overwhelming in selection. Unless you go to a stereo shop that is high end, you won't get but one type which is generally an in-line made for one type of wire or connector.
Noise can come from so many places;Engine alternator, spark plugs, loose connections, etc. RCA connectors are very susceptable to noise as they have all of the highly condutive metal all the way around a high power, or high signal, connection.
So, you need a specialist. Belwo are a few noise filter shops that make them for cars and you can read tech atricles on their pages and call them about the type of noise filter you need. It sounds like you eliminated a few possibilities, but when you get some types of noise that has to do with the way a few electronic components are grounded, it is nearly impossible to find the source of the noise.
Not many people come back and thank me for helping them, so I really appreciate it.
Tuesday, September 27th, 2011 AT 9:25 AM