Still require additional advice.

Have posted a few times about head unit and amp problems supplying the proper amount of power to the Rubi's. Everyone's advice was greatly appreciated. I did everything I could from the advice given but still had to take the boat to an installer. Here's the problem. Several people here said that I had to boost the voltage from the head unit up from the 2 volts. Also a couple of installers locally said the same thing. The installer I used came highly recommended and he said I did not need the pre amp or line driver to boost the voltage, not sure why. Picked up the boat today and he found the front RCA outputs bad on the head unit, so he ran them off the rear. It didn't sound any different.

Anyone with Rubicons, NVS or Wetsounds, how loud are your speakers when riding 70-75 feet? I keep hearing that they are concert sound and you can not have them cranked. If that's the case, I still have problems. Sorry for the lenghty post.