SPL

Sound pressure level in dB — anchored to real sounds, or it means nothing.

SPL measures acoustic pressure on a log scale: 30dB is a whisper, 60dB conversation, 85dB the common mix-reference region, 100dB+ is where our meter draws clip-red. Ten dB more reads as roughly twice as loud and costs ten times the amplifier power. Sustained 85dB+ exposure deserves respect — take breaks, and check levels with any phone SPL app.