Essentials

Types of ADCs: How They Work and What They’re Used For

Analog-to-digital converters (ADCs) are essential for bridging the analog and digital worlds and are used in a variety of applications. There are many types of ADCs, 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…

THD+N Specifications in Audio Interfaces: Percentage vs dB

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…

What is Total Harmonic Distortion plus Noise (THD+N)?

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 is measured as the ratio of energy from the harmonics and noise relative to the energy from an input signal. Many modern audio devices, such as audio interfaces, have relatively low…

What are MIDI Channels?

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,…

What are MIDI Modes (and How Do They Work)?

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…

What is dB SPL (and How Does it Relate to dBA and dB HL)?

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…

What is the Noise Floor in Audio Interfaces?

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…

What is the Difference between MIDI and Digital 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…

What is Equivalent Input Noise (EIN) in Audio Interfaces?

Equivalent Input Noise, or EIN, is a measurement convention used for specifying noise levels in pre-amps. It is expressed in units of dBu or dBV and is quoted as a negative number. Typical values of EIN are in the range of -120 dBu to -129 dBu. EIN is an important consideration for audio interfaces that…

What is dBFS in Audio? How it’s Calculated and Used

dBFS, or dB relative to full scale, is a metric used in digital audio systems. It is derived from dB, which compares signal levels, and measures how far a signal’s amplitude is below its peak amplitude. dBFS has practical benefits in digital production environments, allowing calibration to a maximum reference point and helping to ensure…