Hi, i drive a 06 scion tc. I recently installed a 10" sub with 250w class d amp. I kept the factory head unit and used a line-out converter to tap into the rear speakers. The sub sounds amazing when you play a cd or play the radio. Bass is deep and you feel it all around you.... The problem occurs when i switch to my ipod. The volume and quality of the music is no where near what im getting from a cd or radio station.

I tried playing with the eq on the ipod, failed. Tried improving the quality of the actual songs on itunes, failed. I have the ipod connected in my car through the actual ipod cable that came with the upgrade from scion. The sound quality on the cable and the aux cable both dont sound as rich and full as a cd or radio station.

I also played a cd that i burned into itunes and is on my ipod. Played the same song on the cd and ipod and switched from ipod to cd modes and the difference in quality was significantly lower on the ipod.

Any ideas on what may be inhibiting my system from allowing my sub to use its full potential while on the ipod option? How to fix?