AC3 Question
 

I've been working on a short video clip and the last couple of days has found me in a bind. The clip is a title with exploding letters. With each letter explosion I have a wave file that is in sync in a 5.1 layout. It's 1 wave file for each letter of a 2 row title. If the letter is on the right top row, the the right front speaker has the explosion. If it's a bottom row left letter then the rear left speaker has it and so on. When I play back the clip in the preview, everything is perfect, I get sound from the RF, center, LF, RR, and LR speakers when I'm supposed to. Then when I render it to an AC3 file I lose the center speaker and that sound goes to both front speakers. Leaving a decent hole in my soundstage. I checked all my surround sound settings, the surround panner, properties, AC3 config and I can't figure out what is wrong.

Any suggestions? Thanks!

Sorry for my first post being a question.... lol

Oh yeah, I'm using Vegas 7.0e.

Can you post your VEG file?

Did you go into the "custom" dialog when rendering, and spec the 5.1 template? For some reason, the 5.1 template is not available until you go into the "custom" dialog.

Yeah, I'm using the 5.1 template... unfortunately I'm getting a 4.1 file... no center channel.

Sure.

http://rapidshare.com/files/59888644/Untitled.veg.html

I finally had a chance to inspect your VEG file. It looks okay, so the problem is either in rendering, or playback. Tracks 2 and 8 have information in the center channel so it should not be silent.

How are you playing your AC3 files? Do you have a software "surround mode" enabled, like "SRS CircleSurround" or "Dolby Pro Logic II"?

No, everything is hardware... I have an Audigy 2 soundcard with a Creative 5.1 system. I just noticed that if I play the .ac3 file in Cyberlink PowerDVD 7.2 I lose the center channel, if I play it in Nero ShowTime 4.1 it plays fine. I'm using Sony DVDArchitect 4.0b to make the DVD and it also loses the center channel. I never had this problem before, it just happened one day and it hasn't fixed itself...!

So the problem probably isn't Vegas... I'll keep working on it. Thanks for the help!

That explains it! Go into PowerDVD's audio settings and see what has happened. The AC3 decoder might be doing something funky. Nero has its own AC3 decoder. PowerDVD uses Cyberlink's.

i'm losing center speaker after rendering as well!
 

vegas 7 & DVDA 4 and 5
after rendering, my theatre center speaker plays zilch!
other dvds are fine, other front and rear speakers i pan to using surround panner per track, in Vegas video, work fine, not the centre speaker

vegas preview window plays center 'sound' [though i have2 speakers attached to my editing pc] but after rendering DVDA plays nothing in preview and in my theatre sound system.... nothing

all other panned sound to speakers are ok.

any ideas??

yours sincerely,

Martyn Biesheuvel.