Audacity Forum

Is there any way I can record using more than one input? As in, I have an M-Audio interface with line-in, which works for recording by it's self, and I also have Sound Blaster Interface with the same kind of line-in. So can I use both line-ins at the same time?

Windows will only recognize one Sound Device at a time. You can point it to an external USB mixer or a computer microphone, but not both. The mixer will, or course mix as many microphones as you can fit, but it all get smooched down to stereo before it gets recorded.

That's not to say you can't do it at all, we posted a long thread of different ways to record more than two different sounds at once (generally stereo).

You do have to plan ahead. You just can't pick up several different devices from your desk drawer, plug them all in and press record.

http://forum.audacityteam.org/viewtopic ... 27&t=38626

Koz

As Koz has indicated, the short answer is "no, not with Audacity on Windows".

Although some other software can record from multiple sound cards simultaneously, the results of doing so can often be disappointing. For most consumer level sound cards, each sound card will run independently using its own internal clock signal, the result of which is that the tracks will tend to drift out of time with each other. Other problems are that recording from multiple devices simultaneously increases the demands placed on the system to maintain continuous data transfer from the multiple devices to disk, and this can cause "drop-outs" which can sound like short gaps in the recording or bad distortion.

The preferred way to record multiple tracks simultaneously is to use a specialist sound card that supports multiple channel recording (such as the delta 1010 listed on the page that Koz linked to). Even with an appropriate sound card, Audacity may still not be able to record multiple channels simultaneously (it depends largely on the sound card drivers), in which case you would need to use other software such as Cubase, Sonar, Reaper, ....

Audacity on Mac OS X and Linux should be able to handle multiple sound cards, but not necessarily very easily and not necessarily very well.
It may also be possible to record from multiple sound cards on Windows by using Virtual Audio Cable, but again this may not be easy and may not work well. (your mileage may vary).