Podcasting Guide | PoducateMe

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Figure 15: Audio level meter.

In Figure 15, the dynamic range is represented by the measurement of the loudest to the

quietest part of the audio signal (A). Since the dynamic range extends from -6db

(loudest) to –70db (quietest), this audio selection is said to have a dynamic range of

76db. The part of the audio that falls below –70db (B) is made up of hiss and hum

generated by audio equipment and is known as the “noise floor.” The difference between

the loudest part of the audio (-6db) and 0db (D) is called “headroom” (C). In this example,

we have 6db of headroom.

With digital audio, “Clipping” occurs when spikes in volume are not held in check and

your levels exceed 0db. The tops of these signals are cut off, which causes a harsh form

of distortion that sounds like shattering glass. Needless to say, clipping should be

avoided at all costs.

Generally, In order to cleanly capture the subtle details of sound with a wide dynamic

range (such as speech), you want to record the audio as loud as possible without clipping

the signal. If you set your recording levels too low, you’ll have to boost your file’s volume

in post-production, which will also increase the level of noise in your recording.

Unfortunately, when you raise the input volume of your microphone, you not only

increase the volume of soft tones, but loud ones, as well. This can cause clipping in the

more powerful parts of your signal. Dynamics processors are used to relieve this

problem.