When I record from youtube, the sound is extremely tinny. I don't get that with the internal mic.
Any suggestions how to fix that?
Trying to record sound from a speaker with a microphone is never going to give good results. Alternatives:
a) Search for "youtube download mp3" in duckduckgo/google/whatever and use any of the tools to extract the audio from a video.
b) Or install a "virtual soundcard" on your computer and use it to send the audio directly to hard-disk. (There are solutions for this for Windows, Linux and MacOS.)
Hope this helps.