dBu:				Comment:
+30	╶		╴	analog clipping point
		|		↕ analog cushion
+24	╶		╴	nominal level
		|		↕ 20 dB crest factor
+4	╶		╴	nominal level
		|		↕ example 76 dB SNR
-72	╶		╴	example analog noise floor