Last question I swear! lol After weeks of HB'ing my DVD rips into m4v's, I've noticed/learned that OS X Quicktime X or 7 do not process AC3 very well (VLC seems to be the only media player that does). I have been encoding my m4v's audio w/ AC3 only tracks: 1. AC3 (5.1) / AC3 / 6-Channel discrete / 48Hz / 640 2. AC3 Passthru 3. AC3 DD / Stereo I thought this would "future proof" my DVD's to near lossless quality so that I can toss them. However, I learned "AC3 Passthru" is all that is needed as 6-Channel discrete at higher kbps adds nothing to the audio. However, using AC3 for all my audio tracks has produced m4v's that crash Quicktime X or produce movies with severe static no matter what audio track I select. In some cases OS X forces an m4v to be played in QT 7. I've used Subler to alter the tracks, turning some off/on. Below is a pic of Subler with an m4v encoded w/ 3 audio tracks; 1 − 6-channel discrete, 2 - AC3 Passthru, 3 - AC3 Stereo. I noticed that 2 - AC3 Passthrough, lists 2-channels: *I renamed the audio tracks in Subler improperly as I thought the third audio track was the director's commentary as it listed 2 channel audio for tracks 2-3 but track 2 should be AC3 Passthru *Also, the video tracks had "Unknown" for language which I changed to "English" Is that correct as I thought AC3 Passthru/through was passing the audio untouched, almost lossless. I encoded an m4v that was having audio issues and used this setup: 1. AC3 Passthru 2. AAC Stereo It played fine on my Mac Pro in all applications. Is this ALL I need for audio, nothing else, and it will play full surround on my Pioneer VSX-33 (which handles all my m4v's on my aTV 2 with no issues)? Thanks to everyone who has put up with me over the past few weeks and has taught and helped me so much!