BD-P1500 Audio Encoding Question

[fastawdtsi]

Hey everyone';

I now have a BD-P1500 that runs through my HTR-6090 receiver through HDMI. I'm so indecisive on what audio format to use in the "Digital Output" option of the blu ray player.

I have tried all three with Ironman on blu ray and cannot seem to make a decision. PCM, from what I've read is the way to go, since my receiver does not decode TrueHD natively. My receiver recognizes the PCM audio stream and identifies it as "MPCM" which I believe means "Multi-channel PCM." When comparing the PCM and bitstream(s) digital output options of the player, I noticed that the bistream(s) options seem to have a fuller sound, while the PCM needs a bit more volume to compete -- is this normal?

Secondly, it looks like the blu ray player/disc when in bitstream (audiophile) mode, it still outputs a 5.1 Dolby Digital audio stream to the receiver, I assume the blu ray disc also has a DD 5.1 audio track? If thats the case, if/when I get a 7.1 TrueHD blu ray disc, will there also be a non-HD 7.1 audio stream when using the bitstream (audiophile) option?

Thanks so much,
Ernie