Equivalent noise

- [Instructor] One specification that's not on the Beta 58 … or SM57 spec sheet is equivalent noise level. … Self-noise, equivalent noise … being pretty much the same thing this … is 6 dB-A weighted scale. … A-weighted focuses more on where our ears are most sensitive … and that's between about one kilohertz and four kilohertz. … So if you see the A-weighted scale you'll see … that it rolls off in the low end … and it rolls off in the high end. … The C-weighted scale which isn't used here … is a flatter scale that represents amplitude … throughout the entire audible spectrum. … You might roll off a little bit at the bottom … and a little bit at the top … but it's pretty much a flat responding spectrum. … So this noise level within the range … that we hear best is 6 dB. … What that means is that this microphone's self-noise, … the amount of noise that … it makes internally is about the same … as an ambient acoustic volume level of 6 dB. … This is quiet mic, that's a low spec. … If we look at the P820 Tube microphone …