I only have to turn the volume way up when I'm playing an HD-DVD. If I flip the disc over and play the standard DVD side, I have to turn the volume down because it's "normal." I'm using the optical audio connection. I think it has something to do with HD-DVD's being converted to DTS. I've played with all the HD-A2 settings such as bitstream and downmix pcm, etc and nothing changes it. I think people are only having this problem if they use optical audio, not hdmi audio, but I could be wrong.
Samsung 85" 4K, Dolby Atmos 7.1.4 with MartinLogan Theos, Stage, Motion 15, EM-R, Seaton Submersive F2, Denon AVR-X5200W