Problem: track FX are creating lags in audio

[Adi Head]

I'm creating the soundtrack for a short animation film on Vegas Pro 8b... and I'm running into some audio problems that somehow have to do with the track FX.

THE PROBLEM
Somehow the sound of audio events that are on tracks which have some track FX, such as reverb, begin late - a couple of seconds after the cursor has passed the start of the event. And then the sound continues 3 or 4 seconds after the event has ended. It's as if there is some kind of lag. I rendered a short part of the project to see if it is just a problem with the playback... and the rendered .avi had the same lagging audio (only with the sounds on the tracks with track FX).

SOME SPECS
Intel Core 2 Quad Q6600 @ 2.40GHz
OCZ 2x2048 DDR2 memory
Asus P5Q-PRO mainboard
M-audio Audiophile 2469 delta series - PCI soundcard
Windows XP sp3

I'm not sure if it could have anything to do with this problem - but I though I might add that in the Vegas project there is one video track containing the animation film. The film was made in Flash. Each scene was exported from Flash as a jpg sequence. The jpg sequences were then imported into Vegas and rendered to an .avi file.
The video file I am working with to create the soundtrack is this .avi file of the film.

Can anyone please help me?

Thanks!

[Edward Troxel]

All of my audio tracks have the default effects. I've never noticed that even when adding other effects. What if you post your VEG file and let us see if we get the same results with our clips?

[Adi Head]

Originally Posted by Edward Troxel

All of my audio tracks have the default effects. I've never noticed that even when adding other effects. What if you post your VEG file and let us see if we get the same results with our clips?

Okay, I did a bit more testing. It seems like it's one particular effect that's causing the problem: Pitch Shift.

After removing Pitch Shift, it plays and renders fine.

I'm still not sure why Pitch Shift causes this audio delay. If it were just the playback, I'd figure it has something to do with a lag in processing the effects in realtime, but it renders with the lag as well.

Anyway, in case it has to do with my particular .veg file - I've attached the file with just the video track, the problematic audio track and a copy of that audio track without the extra track FX for comparison.

What do you think?

[Edward Troxel]

There's a "Preserve Duration" checkbox in the middle of the Pitch Shift dialog. That is unchecked in your VEG file. If you check that box, the delay should then be gone.

[Adi Head]

Originally Posted by Edward Troxel

There's a "Preserve Duration" checkbox in the middle of the Pitch Shift dialog. That is unchecked in your VEG file. If you check that box, the delay should then be gone.

Right on. Thanks!