Mix 51 is a low-cost, entry level 5.1 surround panner and mixer plug-in for Pro Tools LE. The panning and mixing operate as RTAS plug-ins that output the 5.1 mix on six mono or three stereo aux tracks. When it comes time to export your 5.1 mix so you can deliver it or encode it for DVD, you can accomplish it in two different ways:

Method 1 – Bounce-to-disk
Pro Tools LE’s bounce-to-disk feature is limited to stereo so exporting your 5.1 mix using a bounce has to be done in three passes. First do a bounce of the L and R channels. Then the C and Lf channels, and rename the files to use .C and .Lf suffixes. And then the Ls and Rs channels, and rename the files to use .Ls and .Rs suffixes. Be sure to set the Pro Tools LE output type to multi-mono. After three bounce passes, you will have six mono files that you can deliver or encode for DVD.

Method 2 – Re-record
If you have six track voices available, you can create six new tracks and record your mix to them in one pass. Assign your mix outputs to busses and set the new tracks to use the busses as inputs. Record enable all six tracks and now you can record the mix to them in one pass.

Mix 51 version 1.1 has a great new feature that makes it easier to set up a low-budget surround mixing system with Pro Tools LE. Mix 51 now has an additional output that is a matrix-encoded stereo LtRt down mix of the three 5.1 busses.  The down mix is compatible with Pro Logic II decoders.  Pro Logic II will decode from stereo back to 5.1.  That means you can use a stereo interface like Mbox 2 and connect it to a 5.1 home theater system and voila, you have a 5.1 surround mixing system.