Hello! I have a Tascam mixer and Audacity will only let me record out or 2 microphones. IN1 and IN2 record but IN3 and IN4 won’t pick up sound. In my preferences it only gives me the option to MME, Windows DirectSound, and Windows WASAPI as my Host (all only allow for 1 mono or 2 stereo as my for my channels) I have my mixer chosen as my device for recording. Any ideas?
There is a section of the forum for multi-channel.
https://forum.audacityteam.org/t/multi-channel-recording-in-audacity/15644/1
In order to get maximum compatibility and customers, mixer makers configure multi-channel as groups of stereo. You’re much less likely to send the mixer back if it does something. I think you’re expected to run the makers custom software to get multi-channel.
There is one odd problem. Audacity doesn’t support ASIO software packages. So if the mixer uses ASIO to get their tricks, that’s not ideal.
Koz
I have a Tascam mixer
Is that actually a mixer or an interface? Most USB mixers only give you the stereo mix, but they do give you a mix of all the inputs so all of the mics should work.
If it’s an interface, it looks like some Tascam interfaces ship with Cubase and for multi-track recording you’ll probably have better luck with it (or another multi-tracking DAW).
Is this the TASCAM US-4x4HR USB Audio Interface? When I look at the manual for this baby, it says only WDM and ASIO are supported for Windows. Audacity is shipped with neither. 
I believe cakewalk is free and supports ASIO and you can get a demo of Reaper that also supports ASIO.
If you want to try compiling your own, private, Audacity that does support ASIO, see here: ASIO support in Audacity 2.4.2 - #13 by jademan
I hope this helps. 
I will try this soon! Thanks for the help!
Audacity fully supports WDM drivers - that’s the normal Windows drivers (Windows Driver Model).
Thanks, steve. Perhaps I have that confused with WDM-KS and MME? Also, see Recording With Audacity