Sound Question

If you are using two speakers, make sure to choose the two-channel option for your recever.
You may have the 5.1 option specified.
This will effectively omit the center channel where most of the dialog comes from.

I have 5.1 speakers and am using the 2 additional amps to provide stereo throughout the house for background music. All rooms have 2 NHT ceiling speakers installed.

Check both menus (Blu-Ray player and receiver) and make sure speakers are configured for 5.1 playback.

Next, run the auto-calibration feature on your receiver (if available).

Also, make sure channels are connected correctly. I.E.,
make sure the center channel output is going to the center channel, the right to the right, etc. This is easy to screw up.

Finally, if your receiver allows individual channel volume control, make sure your center channel isn't set way below the others.

Hope this helps