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How can I record what the sound card is outputting?



Try this

C:\Program Files\National Instruments\LabVIEW 7.0\examples\sound\sndExample.llb  Record Wave

and set the record input to "what u hear", "stereo mix" or "out mix".  Naming is driver dependent





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Message 21 of 27
Hi Folks,

Even i'm facing some problem to record the sound from a sound output device...
Here i will get the sound from a Speaker
Instead of putting a mic in front of it i want to record directly the sound from it through the hard lines inputted to PC.
My scenario lies here.
Will take two wires from the speaker (Car radio Speakers) thru one male connector take that to comp and record it...
Right now its not recording anything...
Please give me  a proper idea how to record the same.....
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Message 22 of 27
The speaker output wires from a car radio are typically too high power to record into a computer sound card.  It can be done if you use the line input of the sound card (not the microphone) and turn the volume on the radio very low.  However, doing this puts you at risk of destroying the inputs on your sound card.  If you use the microphone input, the risk is even greater.  You can use the sound recording software that comes with your operating system to make sure your hardware is working before pursuing a LabVIEW solution.
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Message 23 of 27

Hello guys,

Getting back to the original topic tittle, I am also looking for a direct way to record what sound card is outputting.

Windows 8 has disabled the access to Stereo Mix (or whatever you call) because of content copying license. Even if you have latest drivers (I tested with both Realtek HD audio device or IDT High Definition device) it will NOT give you access to enable the Stereo Mix as a recording device.

But many software, even freeware, can access the "Playback devices" to read audio data and that is the key for this puzzle!


LabVIEW sound card VIs and even Wave_io_0.7 library require you to choose Record device to read data or Playback device to write data. And we want to use a Playback device to read data.


I bet this can be done using some Windows DLLs but I am not sure how to do that.


Any ideas?? Cheers!

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Message 24 of 27

There are a couple of possible solutions, and I have tried neither so cannot tell you whether they would actually work.


  1. Try accessing the sound acquisition through ActiveX.  I seem to remember seeing posts on how to do this on these forums.  You should then get access to all the modes available with your sound driver.
  2. Use the "analog hole".  If you can listen to it, feed the sound output into the line input of your sound card and record directly.  Make sure you mute the sound input first, or you could get a very fast feedback which destroys your sound input or output drivers.  Analog recording will result in degraded sound quality, which may or may not be an issue.  The degree of degradation will depend upon your hardware.

As always, recording things you don't own is subject to the usual copyright restrictions.  Be a good citizen.


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Message 25 of 27

Thanks, I will explore more the first option.

The intention is not to record anything, but experiment analog gauge VU math models in LabVIEW.


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Message 26 of 27

The way to get the problem solved is using a third-party software. Just install one of the recorders like VideoSolo Screen Recoder on your computer, then you can record any sound you want to save.

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Message 27 of 27