Why does input source switch in middle of recording audio?

wwindsor wrote on 5/12/2009, 1:40 PM

I was recording from a vinyl record using Audio Cleaning Lab. Twice, in the middle of the project, line-in was suddenly "de-selected" (un-checked) and microphone was suddenly "selected" (checked) in the recording control panel, creating a gap in the track. The sound coming from my speakers was unchanged - viewing the recording display that tipped me off - just a flat line instead of the audio pattern. What happened?

Comments

ralftaro wrote on 5/13/2009, 6:48 AM

Hi,

I suppose you're using Windows Vista, right? Do you have anything plugged into the microphone socket as well? In this case, you should definitely disconnect it. You should only have your actual signal connected to Line In at the time of recording. Even, if there's nothing connected to the mic socket, I wonder whether this is somehow a problem of Vista or the sound driver misfiring and detecting a signal on the mic socket that isn't really there. Make sure your sound driver is up-to-date. Maybe you can also suppress the issue and prevent the unintended recording source switch from happening by changing some settings in your operating system.

Go to the Control Panel and select "Sound". In the "Sound" dialogue, select the "Recording" tab. You should see something like this:

Right-click on the different items and manually disable anything you won't need. Just leave the "Line In" active and disable the microphone.

Just an idea. I've never heard about a problem like this before, but maybe the suggestion above helps. Would be interested in feedback.

ralftaro wrote on 5/13/2009, 7:46 AM

I see. Thanks for clarifying this. Not sure what sound hardware you're using and whether you're using the Windows mixer or a proprietary mixer and configuration software. Maybe you can find a similar way to take care of this on a software level. However, as far as I'm concerned, I'd say just disconnect the microphone and be done with it. :-)

NoTurning wrote on 5/13/2009, 8:49 AM

I usually agree with Ralftaro but here I have to disagree. I do not recommend using Stereo mix (sometimes called What You Hear) as it will record undesired info. as well. There are instances where it will record what is playing as well as what's coming in creating a nasty double track.
A better solution is not to remove your mic and then reattach each time you need it but to simply set your recording to line-in only. Force Magix to use the line-in and keep you mic connected for Skype. Using stereo mix is a fine idea for diagnostic purposes but not great for actual recording. Setting your system up the way you need it is the best solution.
If you can't select line-in from ACL (some cards don't let you) then make the change in XP's control panel, sound and video applet.
Justin

ralftaro wrote on 5/13/2009, 11:47 AM

Hey, just for the record, I didn't recommend the recording of the Stereo Mix. Classic misunderstanding. :-)

The image I posted was just supposed to illustrate that particular configuration dialog in Vista. I was recommending the activation of Line In and the disabling of the microphone. However, that whole part is now moot anyway, since the poster clarified that they're not using Vista.

From what I understand, the poster is already recording from the Line In socket, where their record player is attached. This is working fine and the sound is recorded, except sometimes when the microphone suddenly forces its way into the recording process and makes Windows switch the input, resulting in a silent phase. Once again, that's just my understanding of the problem. It's also something that I only expected from Vista (automatic detection of input sources). But apparently XP is doing this as well.