Is there any way you can post an example of the result?
That might help.

Yes, a bad connection from Mic to Interface could cause weird issues.
Maybe open some other audio recording app and verify the mic-interface-computer path is good. It's one troubleshooting step that should be easy enough.

SM-58s are pretty reliable and battle tested, more likely a bad cable distorting things.

Are you plugging the SM-58 directly into the interface or using a preamp?

The level of the signal varies a bunch depending on your signal path.
If the SM-58 is connected directly to the interface, using Line level is probably wrong, but if it goes to a preamp and THEN to the interface it is likely OK.


I do not work here, but the benefits are still awesome
Make your sound your own!