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Greetings. New here and to the program. Sorry if this issue has been discussed before, I need an idea of what's happening or how to fix it before a festival gig taking place next week.
My first live go with vMix took place Thursday past. The setup was a single camera firewire into the computer. Audio came in via a mixing console into a PCI sound card with stereo ins and outs only. Same computer as the video firewire input.
The computer is getting old, it is a quad core running W7 pro 64 bit, 4GB ram, 1GB video card, nVidea but I can't remember the model. I do have a raid on this machine, but it keeps crashing so I was streaming data to a single 7200 RPM drive. Video was recorded at 720X480 with audio in stereo at 16 bit 44.1.
The video is great, if a little dark, but the audio is filled with digital distortion - drop outs. I have a feeling that my older computer is not capable of handling the data throughput - but I would like clarification or input on this.
First question is, it seems that 24 bit audio is not supported? Is this so?
Second question, how does vMix deal with audio and video? Should they stream to separate hard drives? I am unsure why the audio was so broken up (suspect computer resources). I can confirm that the input levels were not over driven neither at the console or into vMix. It sounds like digital dropouts.
Any help here would be most appreciated. Let me know if you need more information.
Thanks.
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I record my church service every Sunday without any serious issues, except drop frames....
First, make sure that the audio into the PC is not too high....best way, is to use a direct box to convert the audio to low, or mic level, ....If you are going in as Line level, make sure that the card can handle the level sent, and make sure you have the input in the correct jack.....it Must be sent to 'Line', NOT Mic...I use the 'Monitor' output on the mixing console, and set the level from the console about half way, or 2/3 to keep the output as low as I can....
I use vMix to set the recording level, and keep the input where it may max out in the 'Yellow', NOT to go into the 'Red'....keeping input levels low is the key to avoid distortion.....
It is best to use 'Default' settings, as I find I get good results....
Always check your sound before you start to record, and keep your eyes on the input levels......
Next, Listen, listen, listen...always use proper headphones to monitor your sound, rather than look at audio level meters....
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Hi Zentriloquy,
If it is handling the video with no issues, then certainly the audio should not be a problem. Are you using a sound board/mixer or did you use the audio from the camera?
When you say stream to separate drives, are you streaming the live event (ie on Youtube) and recording it locally as well(on your PC)?
Tim
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Thanks for the replies. I am recording from a mixer, taking aux outs into the sound card of the PC recording the video. The inputs are NOT hot. No red, either at the board or on the audio mixer in vMix. The issue is definitely digital distortion, not overdriven distortion.
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@ zentriloquy
Are you able to 'isolate' the possible root of the problem?
How well do your "aux" inputs record on other software aside from vMix?
Is it only in the recording or can you hear it 'Live'?
Ice
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zentriloquy wrote:Thanks for the replies. I am recording from a mixer, taking aux outs into the sound card of the PC recording the video. The inputs are NOT hot. No red, either at the board or on the audio mixer in vMix. The issue is definitely digital distortion, not overdriven distortion. Ah, I see....you are getting a sort of buzzing, or background static type of noise....Sounds like you need some ground isolation....Try passing the audio through a 'Direct Box', and see what happens..... I use the Whirlwind IMP2, which has a 'Ground lift' switch...and my audio is clean.....
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Rank: Newbie
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Greetings again. The noise is digital dropouts. I am a professional sound tech and know my gear really well. The mixer I am using is a Yamaha O1V and the aux outs work fine. In fact the entire audio chain is fine. No noise live of course because the audio for vMix is coming from aux's not from the mains.
The issue is most definitely digital dropouts. I have done a lot of digital recording and the distortion/noise is caused by an interruption of the audio stream writing to the hard drive.
Going to contact support to discuss this, but what I think is that I am going to build a new computer that is more in spec for vMix. I just read all the optimization stuff on the site and will do a bunch of this to the new machine. Also going to try and get away from firewire and into hd-sdi asap.
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in your PC what sound card are you using, could the noise by a latency problem with your sound card?
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Rank: Newbie
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I can't remember the sound card make at the moment and am away from the computer. Will be checking this tomorrow. Also will run audio tests on the card making sure it actually works and helping define the problem.
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