If you want to record a podcast or interview, often you will want to record in the highest
possible audio quality format first, and then compress later.
Recording to a compressed file can result in artifacting and noise - and while you might
not hear it in the initial recording, it can definitely come up if you’re applying any
post-processing to the audio or compressing it again for posting to a podcast host.
BUT you probably want to record yourself and the person you’re speaking with - or other
sounds - to separate tracks to mix best later on, too.
Short of buying an expensive multi-track audio recorder like my Sound Devices MixPre-3, you
need to use a software solution.
But Audacity by default doesn’t record system sound and microphone audio to separate tracks,
and it’s hard to find other software to do it.
BUT I’ve finally found (or been pointed to by the developer in the OBS Discord server)
a build of OBS called “OBS Studio Multichannel” that might solve this dilemma.
While I wish OBS Studio could have an alternate “audio mode” where it only records audio
and records multiple uncompressed WAV audio tracks, this is the next best thing.
OBS Studio Multichannel is a build of OBS Studio that uses more updated FFMPEG libraries
and enables multiple audio track recording for the Custom Output (FFMPEG) recording mode.
This means you can tell it to use your normal X264 or Nvenc or whatever video format and
PCM WAV audio and still have multiple tracks.
(In case you were unaware, normal OBS Studio only allows for single audio track recording
in Custom FFMPEG mode.)
So if you wish to record a podcast or interview with uncompressed audio, download the OBS
Studio MC installer from Github and install it.
Now close whatever OBS it opens up - it opens your normal OBS installation, not the new
one.
You have to go to ‘C:\Program Files (x86)\obs-studio-MC\bin\64bit’ and run the OBS64.exe in that folder.
Make a shortcut to it, if needed, to be safe.
This launches the custom build.
Now duplicate your normal profile you’d use in this scenario, give the new one a name
like “MultiChannel” or something.
Open up the Setting.
Go to Output, Recording, and now change “Standard” to “Custom Output (FFMPEG).”
Now things get a bit tricky here because you have to navigate the custom modes to re-create
your normal video settings.
That is, if you care about how the video looks.
I have attempted to re-make my normal lossless Nvenc recording mode with these settings for
you to compare.
BUT if you don’t care about video at all, set it to libx264 and just kind of ignore
the video settings.
However, you will need to choose “Matroska” as your “Container Format.”
This is MKV.
MP4 can’t usually hold WAV audio streams.
Under Audio Encoder, choose “pcm_s16le” - that’s normal uncompressed WAV mode.
Now you can check the different Audio Track boxes for the tracks you wish to have recorded
and it will put them all in one MKV file.
I also went ahead and put the audio bitrate to the maximum of 4096 just to be safe, but
that shouldn’t affect anything for the PCM encoder.
Might as well be safe anyway.
Hit Apply and theoretically you should be good to go.
Custom Output mode can be confusing and the support team generally doesn’t support it
- but it has been working so far for me.
An issue that I have run into, however, is that you can’t remux the MKV to a MP4 - it
turns out to be 0 bytes.
This, I believe, is because the MP4 container can’t hold WAV audio tracks.
In Premiere Pro CC 2018, as of the April update, you can just edit the MKV file itself and
use Premiere to separate out the audio tracks.
Otherwise you have to get familiar w/ FFMPEG scripting to extract the individual tracks
to separate WAV files.
This isn’t the most elegant solution, but I do think it’s a good option for those
who just want to record multi-track WAV for podcasts or interviews.
I would love to see a dedicated “Audio Mode” for OBS Studio, listed in my “7 Features
I want in OBS Studio” video - but for now, this is the closest we can get.
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I’m EposVox, here to make tech easier and more fun, and I’ll see you next time.