I posted this in a similar thread, but I thought I would put it here also, as it may be helpful to some:
There has been several postings about this "problem". Until DishNet releases a software solution here is a workaround: The problem is that the Hi def receivers are equipped with Dolby 5.1 as the default output, if you are connected to your TV with a hdmi cable and your TV has only 2 speakers then you have Dolby 5.1 being pushed thru 2 speakers. 2 speakers are STEREO not 5.1 (6 speakers) To balance the sound if you are using your stereo 2 speaker TV output, you must reset your Hi def receiver settings. Depending on your Dish receiver model, go to menu/system setup/dolby Digital, then select RF Mode and select PCM only. Then press DONE. This resets the output to 2 channel stereo to meet your TV's stereo design.( Might need to power off and restart your Dish receiver to get new setting to take effect) If your TV has built in DD 5.1 or you are outputting to a DD 5.1 amp or soundbar, then do not make this modification to your hi def receiver. I can't say this will equalize HD and SD sound levels on all TVs, but it did do that on my LG plasma 50" TV. This also allowed me to use my TV's surround sound settings to produce a better sound from the TV's speakers. Hope this works for you!!!