Overdubs out of synch out of time on playback

sticko wrote on 10/25/2005, 8:57 AM
I've just purchased and installed Vegas 6.0 onto my Dell Dimension 9100. I recorded a drum track. Then I overdubbed guitar part on another track(track 2). When I played the two tracks back, the guitar part was out of sync with the drum track. It was ahead of it, and got worse as the track went on. I never had this problem with Vegas 3.0 and my old PC. It was pretty much plug in and play. Don't know if it's a new computer/new software issue.
I'm using a Soundblaster Live card.

Comments

randygo wrote on 10/25/2005, 10:17 AM

I would lose that Soundblaster ASAP and would not even bother trying to record with it. There are so many better options to be had for even $100, M-Audio 2496, even Creative's (Emu's) 0404. Properly configured, these cards should work much better

Randy.
sticko wrote on 10/25/2005, 10:55 AM
That's all well and good, but in the meantime, I need to fix the problem at hand. I need to know what's causing this synch issue.
B.Verlik wrote on 10/25/2005, 11:48 AM
What has worked for me in the past, and I'm still using Vegas 4.0, is in your project properties, check your ruler and use a smpte time code instead of "Time & Frames", I don't know why this works, but it resolves the out of sync issues, at least for me. You may have to start with new tracks for this to work.
I had this problem when I tried to overdub some more instruments to go along with a video track of me and a friend just plain jamming on two guitars. All the new tracks were in a world of their own, as far as being in sync and timing. I tried switching to smpte29.97 non-drop in the ruler, recorded new audio tracks and that seemed to fix it. But I'm the only person I've heard report this.
sticko wrote on 10/25/2005, 12:26 PM
Thanks for the reply.

The ruler was set to "SMPTE Drop(29.97 fps) Video" not "Times and Frames." I switched to Non-drop with the same results. By about 45 seconds in, the guitar is about a half beat in front of the down beat.
randygo wrote on 10/25/2005, 2:54 PM

You might try setting your project at 48KHz, and see if things work better.

Soundblaster Live, at least what I can tell from the volumous postings available on the web, since about 1999, does some weird internal conversions between 44.1KHz and 48KHz, which is supposed to be transparent to the user, but can cause all kinds of havoc with drift, phasing, etc...

It's just a known notoriously bad choice for any kind of multitracking. I would recommend Googling this for yourself.

If you value your time and sanity, I would still recommend you replace the card.

Randy
randygo wrote on 10/25/2005, 3:03 PM

Or, If you prefer to keep the SoundBlaster, you can do what this user did :-)

"If you need a very stable clock then desolder the crystal of the sound card and apply a externally generated clock signal. I just did this with a Creative Soundblaster Live 24 Bit. It uses a 24.576 MHz Crystal. Instead of this i applied a externally generated 25 MHz signal that was derived from a rubidium frequency standard. The sample rates are of course wrong by the amount of clock frequency difference, but are very stable...to say the least. Note that you need to apply the external frequency in order to boot or shutdown the pc with a so modified sound card plugged in. "

http://groups.google.com/group/comp.dsp/browse_frm/thread/cd9a27cf04703cb1/dd3387085eac845b?lnk=st&q=%22soundblaster+live%22+drift&rnum=9&hl=en#dd3387085eac845b
randygo wrote on 10/25/2005, 3:15 PM

Here's a plausible explanation of the problem. Essentially, the record and playback rates are so very slightly different at 44.1KHz that the drift will occur between the two tracks.

Yikes! That is pretty bad.

In any case, it looks like working with the card at 48KHz is a workable solution, although you will suffer an additional sample rate conversion when you burn to CD.


http://www.multitrackstudio.com/feature.php

"Creative Labs SoundBlaster Live! soundcards (and its cheaper brothers like 128, 512, 1024, Ensoniq AudioPCI) use a slightly higher samplerate for recording than for playback at a samplerate of 44.1 kHz (at 48 kHz this problem does not occur).

This leads to multitrack recordings being out of sync. MultitrackStudio features a unique compensation for this effect. Recording at 44.1 kHz makes sense if the recording is to be burned to CDR."
sticko wrote on 10/25/2005, 3:29 PM
Thanks for the info randygo.

I'm ditching the SB ASAP. For now, I THINK I may have it worked out by going to settings>control panel>device control and setting it to 96/24 and the same in Vegas>proerties>audio. So far so good.

Thanks again for all the info!!
B.Verlik wrote on 10/25/2005, 8:29 PM
It's been so long, I forgot about the 48Khz thing. Mine is always set to that and if I need to make a CD, I'll convert it, in Vegas to 44.1Khz. I'm not using a soundblaster. I'm using a Creative Audigy2 Platinum. Most audio engineers complain about them to. (Figures that the card you find in stores and that you believe is supposed to be "top-notch" turns out to be crap and I could've had a real good one for about the same money I shelled out.)