Guys a little update. Been messing around today and it finally works! the gain wasn't turned up lols. I turned the gain up and all is good but i need to set it properly, i.e 75% volume than adjust accordingly.
Also after a good hour of music ive noticed the amp went into protection mode. This has never EVER happened before, any ideas?? Could it be anything to do with the gain? or is it just getting hot because no air is getting to it? (amp is in the spare wheel well).
On a side note, I can not believe this sub is only rated at 300w RMS it bumps hard, now i know why JL is rated.