Canopus ADVC 100 left channel audio fade in/out over time

[Bizuser]

Oh my ... I've been captuing a whole slew of TV shows using my Canopus ADVC 100 device, and doing converstions to MPG for subsequent burning to DVD. I've been testing/previewing/burning DVD RWs to ensure good video, and using all the wonderful suggestions in this guide, getting great results. I thought everything was going so well ...

But then I finally played a sample DVD on my 'main viewing system' (a big screen TV with dolby surround, etc) ... and noticed the sound in one channel (left) was virtually non-existent. Further testing showed that the left channel goes from 'normal' to 'almost nothing' at various times. I wasn't noticing this in my earlier tests as I was a) looking for video problerms, or b) audio synch problems, not thinking to listen to the audio quality (figured that would be a no-brainer).

Anyway, played the original capture AVI through headphones, and sure enough, the left channel constantly changes. The shows in question are Nova documentaries, lots of talking heads, no movement - thus, no possibility of 'stereo effects' ... the guys voice just fades in, fades out, no good reason.

I played several different clips, they all seem to exhibit this. I checked all the connections, nothing looks bad - and anyway, bad connections would tend to give rise to static, crackling, and quick changes. My changes are relatively slow, and once the change occurs, it could stay that way for minutes at a time. The sound never goes to 'nothing' - just goes very quiet. In one scene, a guy is being interviewed at his desk, and the volume just fades to almost zero in the left channel (but not TO zero - can still hear something in the headphones).

I have the canopus connected directly using monster phono cables to the output of my cable decoder box. From the canopus onwards, there's no separate channels.

It's possible this could have been an issue with the broadcast, but I noticed it with captures at different times, and on different channels (History channel and PBS/Channel 9).

So ... anyoene else noticed this with the Canopus device?

[NightWing]

Nedd to figure if its the box or canopus. So here goes.

What else do you have hanging off of the Audio lines from the decoder box. Anything else?

Going to sound stupid but can you flip the audio channel cables? R to L and L to R. Does the problem change?

Or split the audio. Feeding it to a vcr and see if it is getting the same audio change from the decoder box.

Or feed the Canopus a audio source from another source. Would be good to use a Y to split audio into two parts and feed each channel equaly. Easer to see if you have a problem.

Contact the provider and see if they are having problems or switch out that decoder box.

[Bizuser]

Thanks for the suggestions.

I don't have anything else in the audio chain - just two monster cables straight from the cable box to the canopus.

It could have been a broadcast problem just that day, or, a loose cable.

Now I've noticed this, I'm paying far more attention. I did a bunch of captures today, and listened through headphones as the 'feed' came in (through scenalyzerLive), and heard no problems. So I'll just keep an 'ear' open for this!

Thanks again. Sadly, the documentaries I recorded are not likely to be broadcast again for at least a year (9/11 stuff). Guess I could buy the DVD from Nova and History Channel.

[NightWing]

Hope the audio stays together for you!

If all else fail some video editors will let you much with the audio levels. Not a perffect solution but could some what save it. Else pull the other track over for those weak spots.

[Bizuser]

Re: Pulling the audio channel over - any recommendations for a tool for that? I'm not an audio fanatic, so don't follow all the various tools. A tool to simply replicate right channel as left would suffice; either for the whole file, or, selectively. Something freeware, and not too advanced!

[NightWing]

Not sure if cool edit would or even primiere. This is were a good tool shins.