What’s a Decibel!!?

Understanding Decibels: A Guide for Audio Engineers

Despite my formal education and experience in top recording studios, I often encountered basic concepts that puzzled me. One of those was the decibel. This blog is here to demystify such concepts.

Types of Decibels

**dBFS (Decibels Full Scale):**

- Used in digital audio.

- Measures signal amplitude.

- Ranges from negative infinity to 0 dBFS, with 0 dBFS being the max level before clipping.

**dB SPL (Sound Pressure Level):**

- Used to measure real-world sound levels.

- Positive values, like 140 dB for a jet engine or 30 dB for a quiet library.

Practical Applications

When mixing, understanding these decibels is crucial. For instance, a WAV file's perceived loudness depends on the playback system, not just its dBFS value.

Fader Adjustments:

- In Pro Tools, raising a fader by +6 dB adds 6 dBFS to the initial volume.

- If your snare hits -5 dBFS and you add +4 dB, it now hits -1 dBFS.

Why It Matters

Grasping these concepts ensures consistency and quality in your mixes. It helps predict how your mix will sound across different playback systems.

Have questions? Feel free to ask!

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