I have a Slingbox Pro-HD connected to a DirecTV HR20 receiver via the component video and digital audio outputs. The Slingbox is sending the Dolby Digital 5.1 signal in the stereo channels. The iPad player plays the surround channels with the main channels through my headphones, but the audio playback has a tinny, and excessive echo, quality because they aren't properly balanced with the main channels. Is there a way to balance the surround channels (lower their volume) relative to the main channels to improve audio playback? I haven't found any way to adjust audio playback, other than volume control, in the iPad app. Am I missing something?