Gain to Decibels

The Inverse: Gain → dB

In the previous lesson we converted dB → gain. The inverse converts a linear gain value back to decibels:

dB = 20 × log₁₀(gain)

When Is This Useful?

• VU meters: show the current signal level in dB
• Metering plugins: display loudness in LUFS/dBFS
• Normalisation: "how many dB do I need to boost this to reach 0 dBFS?"

Key Values

Note: doubling the amplitude adds exactly 6.02 dB (20 × log₁₀(2)).

Your Task

Implement gainToDb(gain) that converts a linear gain to decibels.

Run your code to see a rising volume displayed in dB.