RCA line noise has been a major issue for car audio installers from the beginning of car audio. The RCA signal from a head unit is a very low level signal, and it is fairly easy for a noise source like an ECM or other component of the cars electrical system to enter the signal path through the RCA cables. This is even more problematic with today's very low output head units. To make matters worse, different equipment manufacturers use different methods of referencing the signal ground to the main electrical ground of the car. If these methods do not match well they create a "ground loop" causing noise (whine) in the signal. So what can be the solution to the problem? Zapco introduces the ASP-L2T signal noise eliminator. The ASP-L2T utilizes custom designed and custom wound high efficiency transformers and other high SQ components to remove the direct connection between the different reference ground systems and eliminate noise, without affecting the bass content of the signal and without adding distortion into the signal.