Was that not true in your other CD players?
The best explanation comes from this other post:
http://www.highdefforum.com/showpost.php?p=151905&postcount=1
This could simply be due to the setup parameters in your player versus your
AVR. Likely the crossovers or the subwoofer channels levels are not the same.
The subwoofer level in the player is 10 dB lower than it should be (all speakers, including the sub, are set at 0 dB level in the player) and to compensate, I set the GAIN at the sub higher by some 2 o'clock. I then get the same volume from all speakers compared to SPDIF. But the sound is completely different.
Again, what is this in comparison to? I suspect any DD TrueHD mix is a remix, so that introduces a potentially big difference from any other version right there.
5.1 DD TrueHD requires me to use the 5.1 multichannel analogs since my a/v is not accepting HDMI inputs/output. If you visit Dolby.com you will have better explanations than one I can give you. This lossless audio codec reproduces the Master audio of the film.
Is the HD player applying some 'surround' DSP to the analog outs like DPLII or DTS Neo?