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Old March 20th, 2005, 04:13 PM   #1
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The craziest audio problem I've ever seen!

Ok listen to this.

After doing some shoots for my movie, I went into Vegas 5 to edit this one scene together and I wanted to watch it on my TV with 5.1 audio just for the heck of it.

I used my GL2 and the Azden SGM- 2x. Here's where it gets REALLY, REALLY WIERD.

I edited the project and all the audio was fine......until I decided to switch to 5.1.

I went from hearing a normal audio signal to hearing practically nothing. I even exported to audio to Nuendo 2 to see what was going on and I had the same problem with the center channel audio. Even though the audio levels were fine in stereo, even prologic using PowerDVD sucked balls.

I thought it was my audio setup or Vegas or Nuendo, but alas it was the microphone. I'm not sure why exactly, but using the GL2 onboard mic didn't create the same problem. It's something with the MONO mic. Although in wave format, the MONO files look like stereo signals, they in fact are identical, cancelling the audio out completely to prologic and the 5.1 center audio channel.

How did I finally come to the conclusive end?

Well..... I took a quasi-stereo program called Hyperprism, a direct X group of plug-ins, and lowered one of the quasi channels, namely the right side, and then, magically, the center channel started sounding louder as I LOWERED the volume.

If someone can explain to me, as why using a "BETTER" mic has screwed me in using 5.1, I'd sure like to know.

In order for me to have a good 5.1 mix, I have to mess with so many single audio edits.....which is so ridiculous. We are talking, probably 100 or so single audio plug-ins just to enable the center channel to work. What is going on?????

Actually, I've just found a solution, however, still not sure why I have to do this, but I have to right click on each audio section and select left or right audio channel ONLY. SO STUPID.

Still, why must I do this?
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Old March 20th, 2005, 04:33 PM   #2
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sounds like inverted waveform might be cancelling the out.To do 5.1 you need at least 2 different channels to easily produce a result.The conversion to 5.1 does some funky things to emulate the seperate channels.
To see what I mean ,take a mono track ,copy it place it in sync with the first,then invert it.Play back the timeline and you'll have no sound
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Old March 20th, 2005, 04:38 PM   #3
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The GL2 mic is stereo. The external mic you used is mono. It's not the mic's fault. It's something in the encoding, or something else.

Keep looking young Skywalker. :)


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Ty Ford
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Old March 20th, 2005, 05:17 PM   #4
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Yea, I got it to work fine in 5.1, but I had to use just the right channel or left channel, but nothing else would would, pretty insane, but I guess it makes somewhat sense if the audio is cancelling itself out in stereo mode. Learned a big lesson!
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Old March 20th, 2005, 05:40 PM   #5
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<<<-- Originally posted by Bob Benkosky : Yea, I got it to work fine in 5.1, but I had to use just the right channel or left channel, but nothing else would would, pretty insane, but I guess it makes somewhat sense if the audio is cancelling itself out in stereo mode. Learned a big lesson! -->>>

Difficult to say without being there. SOME surround processors work by finagling the phase of a mono signal. At any point if the "surround" signal is played back in mono you can get a lot of cancellation.

Perhaps if you had fed it stereo instead of mono, you might have had a different outcome. There's probably something about it on page 413 of the manual. :)

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Old March 20th, 2005, 11:46 PM   #6
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Yea but it's not in processor mode in Vegas. It's in mixing form. Although in PowerDVD it's still not true 5.1, but even prologic wasn't working. It's all very strange.
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Old March 21st, 2005, 07:36 AM   #7
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A solution?

Hi there,

Firstly i must say that i am no pro with audio recording, just a techkie/hifi nut.
It definetly sounds like the sounds are cancelling each other out and if this is possible with your software, this is how u correct it;

Simply reverse the "phase" on one channel.

Dont do both channels as you'll have the same problem again. Running one channel out of phase isnt ideal but its the best sounding solution for this problem.

Ive encontered it with hometheatre setups and car stereo setups ive installed.

Again, I dont know the software so someone correct me if im wrong.

Nathan
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