My system hits less and less the faster i go, like whenever im movin instead of just sittin there it doesnt hit as hard. Is there anything to fix this like capacitor or anything just wondering thanks peace

 

if you have the stock HU you have to disable Automatic Sound Leveling (ASL)

 

the reason is becuase you are picking up road noise. I highly doubt its electrical.
Just like if your crak your windows,you will get more air moving so it will be a little louder.

get some damplifier or dynamat then you will have less road noise and more music