sm7db vs nt1 -6 db audacity

pardon the weird mouth slapping noise, i had no idea it was in the recording the first time listening before publishing. the company shure and i had been in contact, one of the employees attempted to help me with my shure microphone, they eventually came to the conclusion that it was my interface which is a volt 1 that was the issue, i hear no white noise in rode nt1 mic but some in sm7db, odd. nt1 has a low self noise of 4.5dB(A).