Recording USB microphone and line in at the same time

I am a Youtube Commentator and how do you record multiple tracks at once for a duel commentary.

With two microphones and a stereo interface. [u]Here[/u] is an example of a 2-channel interface.

Record one channel on the left and the other on the right. You can adjust the volumes separately. Later if it sounds unnatural to have the voices separated left & right, you can blend them to mono, or blend them slightly. You can also get a multichannel interface for multi-track recording (when you need more than two channels).

Another option would be to get a stereo microphone mixer and plug it into the line-input on your soundcard (if you are using a desktop computer with a regular soundcard). In this application, you don’t need to “mix” with the mixer, you are just using the mixer’s preamps to boost the volume to line-level. [u]Here[/u] is an example of a small inexpensive mixer that also has a USB output so it optionally can be used as an audio interface

The microphone input on a regular soundcard is usually mono, and if it’s stereo you’d need a special adapter to connect tow computer mics (you’d probably have to build it yourself). It’s also “difficult” to record with two USB mics simultaneously .

Note that mixers & these interfaces work with performance or studio microphones (low impedance balanced with XLR connectors) and they won’t work with “computer microphones”.

I am using an audiotechnica at2020 USB and I am wondering how to record that mic alon with the mic line in port on my laptop

By “alon” do you mean “alone” or “along”?

Assuming you mean “along” as in “at the same time”, it’s not a good idea.

If you are on Windows Vista or later (see the pink panel at the top of this page) then you could open “Sound” in the Windows Control Panel, go to the Properties for the USB mic, then set “Listen to this device” to the built-in sound card. Then you can record both line-in and the USB mic by choosing stereo mix as the input device in Audacity’s Device Toolbar .

The reason it is not a good idea is that the USB mic and your built-in sound device are different sound devices and have different audio clocks. As a result, the USB mic and line-in recordings may drift apart over time.

Also you have the recording of the two inputs mixed together so you cannot edit each separately.

Also the USB mic will record delayed because stereo mix has to wait for the computer to send the USB mic input to it.

If you record or import the audio you want to comment on, then set Transport > Overdub “on” in Audacity and record from the USB mic, you can listen to the audio while recording and you will have two separate tracks. You can then use Effect > Change Speed on the USB mic track if it drifts apart.