[BenMcr]

Originally Posted by royaltiger

where as Dolby Digital is a natural 6:1 Surround signal with no conversions

No It's not!

http://en.wikipedia.org/wiki/Dolby_D...configurations

Although most commonly associated with the 5.1 channel configuration, Dolby Digital allows a number of different channel selections. The full list of available options are:

• Mono (Center only)
• 2-channel stereo (Left + Right), optionally carrying matrixed Dolby Surround
• 3-channel stereo (Left, Center, Right)
• 2-channel stereo with mono surround (Left, Right, Surround)
• 3-channel stereo with mono surround (Left, Center, Right, Surround)
• 4-channel quadraphonic (Left, Right, Left Surround, Right Surround)
• 5-channel surround (Left, Center, Right, Left Surround, Right Surround)

All of these configurations can optionally include the extra Low Frequency Effect (LFE) channel. The last two with stereo surrounds can optionally use Dolby Digital EX matrix encoding to add an extra Rear Surround channel.