Dynamic Range Check

Background

Dynamic range represents the ratio between the loudest signal you can hear, to that of the quietest discernible. Dynamic range is expressed in terms of decibels (dB). Being a ratio, decibels have no units. Everything is relative. Since it is relative, then it must be relative to some reference point that has to be defined. Our reference point here is the loudest level you can comfortably hold for one second. This test helps you benchmark the dynamic range of your system.

The file

The file first starts with a reference point: a slightly compressed pink noise which tops at 16-bit full scale (0dbFS). This noise plays for 1s. Adjust the level of your system so that this noise plays loudly, without being uncomfortably loud.

Dynamic Check + Voice Over

Right after the noise, a voice plays back at a specified level. Noise references and voiceovers alternate with each other, with the voice being played at decreasing levels.

Usage

Play the file until you can't hear the voiceover anymore. The dynamic range of system is roughly given by the level the voice message was playing at when it was still (barely) audible. The limiting factor here will be the environmental noise in your listening room. 40dBA is generally considered the ambient noise level in a quiet room, and 90dBA as a upper limit for a loud and "comfortable" playback level. The difference between those two figures is 50dB. This means that - in most cases - you won't hear the voice once it drops below 50dBFS. For those used to extremely loud levels, or very quiet rooms, our test goes up to 78dB below full scale...

Interestingly, much emphasis is put nowadays towards 24-bit recordings, with a dynamic range exceeding 140dB. Our example is only 16-bit, with a maximum dynamic range of 96dB. Yet, it should be plenty enough. Judge by yourself.

Links

• About Decibels
• Table of Sound Pressure Levels