rca to xlr - best way?

www.interlinkhouse.com They do Stealth Cables XLR>RCA or vice versa. Call Serguei Timachew he will sort out what you need.

Or....any manufacturer will make whichever model cable you prefer with the ends that you like! Also...there are "adapters" that you can purchase that convert RCA to XLR. I believe that Cardas makes one. I just bought an XLR (source) to RCA (amp) from www.fatwyre.com.....they made me one from Wireworld eclipse CHEAP!!! and had it to me in 5 days. I bought a cheapie because it is for my headphone amp. I think too much of my equipment to use an adapter (adapters seem to go against the "simple circuit" theory behind high end audio), however, I know high-enders that do use adapters with no/litte degredation.

If your sub is a long way away or has a potential ground loop (ie plugged into a different electrical circuit) you should would be best to use a transformer to convert from single ended to balaced. Then run an inexpesive balanced line to your sub. The transformer will balance your line and match the typical impedence of a balanced line. This will reduce potential ground loops and you will benefit from the common mode noise rejection provided by a balanced circuit. Blue Circle, Rane, and a bunch of companies that specialize in studio or professional audio make them. For a subwoofer appication you don't have to spend a lot.