Line out converter

So I recently installed a line out converter to my stock stereo in my 2006 gmc sierra which has the bose system. The line out converter I installed can handle up to 80 watts per channel head units. My amp is a small 250 watt sony, which I have bridged to a ma audio 8 inch sub. Even with the gain all the way up on the line out converter, the sub is not very loud. My amp is even turned almost all the way up as well. With my kenwood radio in my old truck the sub was just what I was looking for. The reason I chose to use my factory head unit is because the want to much freakin money for the damn wiring harnessses for my kenwood radio. Do I need a bigger line out converter? Any help is appreciated.

bigger is a non-issue, perhaps you don't know how they really work. I would try soldering RCA ends straight on to the speaker leads from the truck and try running those straight into the amp.

P.S. a LOC just cuts the incoming signal level, you might want to start with the gains all the way down if you wire it up without it.

can you please tell me what is line out converter, i wanna redecorate my interior of the car.

LOL, it's not a decorative item. It converts the speaker output of the factory deck into lower level RCA outputs to use on a seperate amplifier.

ok thanks for the information.