Updated October 2026 · Audio basics for beginners
A decibel is a logarithmic unit that compares one level with another. In recording, dBFS measures level relative to the digital maximum, where zero is the top and quieter levels are negative numbers. Learn that the scale is logarithmic and that zero dBFS is the clipping point, and most meters become easy to read.
Every meter in a recording setup shows numbers in decibels, usually written as dB, and the scale can look confusing. Beginners see negative numbers, read them as a sign of trouble and wonder why the meter reads minus something when the recording seems fine. The scale is not complicated once you understand two ideas: it is relative, and it is logarithmic. This post explains both, with the common recording terms.
The aim is to make the numbers on your meter meaningful, so you can set levels with confidence rather than guessing.
A decibel is a way of comparing two levels. It is not an absolute amount, but a ratio expressed on a logarithmic scale. A change of a few decibels is a noticeable change in level, while a change of many decibels is large. Because the scale is logarithmic, equal steps in decibels represent equal ratios, which matches how the ear perceives loudness roughly.
That is why the numbers do not add up in the way beginners expect. Doubling the power is about three decibels, and halving it is about minus three.
Most recording software shows levels in dBFS, which means decibels relative to full scale. Full scale is the maximum level the digital system can store. Zero dBFS is the top, and any level above it is clipping and cannot be stored. All normal levels are therefore negative numbers, such as minus 12 or minus 18, which simply means they sit below the maximum.
The negative numbers are not a sign of a problem. They are the normal place for speech to sit, with headroom below zero for sudden peaks.
Headroom is the distance between your loudest peaks and zero dBFS. If the peaks reach minus 6, you have six decibels of headroom. A few decibels is a sensible margin for speech, and it protects the recording from sudden loud sounds. The headroom post explains how much to leave for different material.
A peak meter shows the single loudest moment, while an average or loudness meter shows the level over a period. Speech has large peaks and a lower average, so the two readings can differ a lot. Set your recording level by watching the peaks, to avoid clipping, and check loudness on the final file, to match a target.
A difference of about three decibels is just noticeable to most listeners, and a difference of about ten decibels is widely heard as roughly twice as loud. These are rules of thumb, not exact laws, and they depend on frequency and context. Use them as a guide to how much a change will matter.
Many beginners think minus numbers mean the recording is too quiet. They do not. A recording at minus 18 is normal. Another confusion is between peak and loudness. A peak can be high while the loudness is modest, which is why both readings are useful.
Phone recording apps often show levels on a simpler scale, with coloured bars or a single bar that rises and falls. The principle is the same as a digital meter, with the top of the scale marking the point of clipping. Learn where the top sits on your app, and keep the voice well below it, even if the app does not show the numbers you expect.
When a phone app does show decibels, compare its readings with a desktop meter using the same recording. A difference between the two usually reflects the way each one averages the signal, not a fault in the recording.
When you read a meter during a session, look at the peaks and the quiet parts together. The peaks tell you about clipping, and the quiet parts tell you about the noise floor. A healthy recording has peaks that stay clear of the top and a quiet floor that stays well below the voice. If either drifts over the session, check the distance and the room before adjusting the gain.
Meters differ in how they measure, and some show peak, some RMS and some loudness. Check which measure your meter uses before comparing readings across programs. The principles above apply to most setups.
A meter is a guide, and your ears make the final decision. The Vocal Checker shows clipping, noise and level problems in a recording you own. The LUFS meter shows the loudness of a finished file. For the level basics, read the gain post in this series.
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Because they sit below the digital maximum, which is zero dBFS. Negative numbers are normal.
It is the maximum level the system can store. Anything above it clips.
A few decibels for speech is a sensible margin, more for loud or processed material.
For avoiding clipping, yes. For overall loudness, check a loudness reading on the final file.
