I recently decided to add 2 subwoofers to my 2007 escalade. I had one sub and amp that I used in a previous car, so I bought an additional sub to match the other. I tapped into the factory subwoofer connection and used a line level converter. From there i ran RCAs to my amp. My problem is that once everything was installed the level of bass seems to be much quieter than with my old set up(same sub and amp just added another sub). Everything is working properly its just not hitting the way it used to, even with the bass boost turned up on the amp. I even tried hooking up just one of the subs exactly the way I had it set up in my previous car and it was still very quiet. Any ideas? Am I getting a weak signal from splicing into the factory sub wires?