Richard Clark and David Navone have done extensive testing to prove shielding has no benefit in a 12V dc environment. The shield is great in a 240/110V AC environment but can act as an antenna for noise in a car. Attach the *drain* wire makes this even worse as now the shield is connected to the chassis and has a direct conection to the noise source.
Unshielded twisted pair (UTP) has been shown to be the most effective as it uses the principle of *common mode noise rejection* that basically means as noise will enter each wire equally and the signal is out of phase, so the noise will cancel out.
In my experience noise entering via RCAs is extremely rare and tends to enter via components like HUs or amps, so IMO its a moot point anyway. The bottom line is though that many ppl still believe in using home audio theory in car audio and its doesn't always carry over. Shielding is a case in point. Great in Home or pro AC situations but useless in our 12V DC situation..
Yes silver will stop oxidisation but I have never seen a rusted RCA yet. Directional is of no benefit but as RCA induced noise is so rare anway it *probably* won't matter.
What another person thinksI have used all types of leads and now use cheap mtx utp leads in my system that cost about $30 rrp each(about 6 pairs), except where the leads go into my amps and could be seen. for these I used $150 PG triple shielded leads caused I liked the connectors matching all my other PG gear
peace
Cyberpunky
This post has been edited by Cyberpunky: Dec 4 2009, 02:12 PM