I have a 2012 Highlander Hybrid with Navigation and rear DVD entertainment. All factory installed. My question is the factory setting of the volume of the rear DVD player. When I play a DVD , listening through the speaker systems, not the headphones. I need to raise the volume to a 32 33 setting to hear the DVD. Normally when I listed to the radio I use a sertting of 16 - 18 volume setting. Why do I need to raise the volume so much to hear a DVD. It is worse when I am traveling on the expressway. Sometimes I need to raise the volume to 45 - 50. I am not changing the balance of the speakers between front and back