Dynamic range compression in audio—audio compression—reduces the dynamic range of an audio signal. The dynamic range is the difference between the quietest and loudest sounds. Audio compression is used in music production, vocal recordings, and broadcasting and helps to deliver a more consistent and enjoyable listening experience. When overdone, however, audio compression can result in…
Essentials
Dynamic range is the difference between the quietest and loudest sounds in an audio system without distortion. It indicates the amount of volume variation (dynamics) in audio. The larger the dynamic range, the more contrast you’ll hear between the quietest and loudest parts. Understanding dynamic range is important for audio production, acoustics, and audiology—it affects…
Analog-to-digital converters (ADC) are essential for bridging the analog and digital worlds and are used in a variety of applications. There are many types of ADC, each with its own history, merits, and limitations. And each has favored applications based on its strengths and weaknesses. In this article, we’ll look at the most widely used…
Total harmonic distortion plus noise (THD+N) is a common metric in audio interface specifications. It measures the unintended harmonics and noise in an output signal relative to an input signal. Audio interface THD+N specifications are often quoted as either percentages (%) or ratios (dB). In this article, we look at the difference between these expressions…
Total harmonic distortion plus noise (THD+N) is a measure of the unintended harmonics and noise in the output signal of an audio device. It’s measured as the ratio of energy from the harmonics and noise relative to the energy from an input signal. Modern audio devices, such as audio interfaces, have relatively low levels of…
MIDI channels are communication pathways between MIDI devices. There are 16 MIDI channels available and each can be assigned to a different MIDI device. Channel assignments allow MIDI devices to be arranged in combinations so that each device responds only to the information intended for it. MIDI is a versatile way of recording notes, chords,…
MIDI modes are settings that control the way that MIDI instruments communicate with each other. They are grouped by the characteristics of MIDI instruments—monophonic or polyphonic—and by MIDI channel assignments. There are four original MIDI modes and two additional modes that were developed for enhanced functionality. MIDI modes offer a versatile way of organizing MIDI…
dB SPL is a measure of sound pressure levels in air. It’s measured in dB and is a standardized way of comparing the sound pressure levels of different sound events. It’s widely used in the field of audiology, which deals with human hearing, and also in audio recording and listening applications. It can be translated…
The noise floor of an audio system is the minimum amount of noise that exists when there’s no signal present. In audio interfaces, the noise floor is primarily caused by the analog-to-digital (ADC) conversion process, the microphone pre-amps, and the inherent noise generated by electronic circuitry. The noise floor is an important factor in audio…
MIDI and digital audio are different ways of recording information about sound. MIDI is a set of instructions about how to generate a sound (using a MIDI device), whereas digital audio is a representation of an actual sound wave. They are both useful ways of producing and arranging music, and each has its own advantages…