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8. A QUICK PRIMER ON DIGITAL AUDIO
To get the most out of your computer and audio interface, it is important to be familiar
with several key concepts in digital audio. We'll explain these quickly below, so that you
understand their impact on performance. Once you are familiar with these concepts, you
will know how to best calibrate your interface and computer settings to handle different
types of audio tasks.
8.1. What is latency?
Latency is the amount of time that it takes your computer to process incoming and outgoing
sound. Latency is an important consideration when recording live instruments or MIDI parts,
as the delay between the input (audio or MIDI) and the audio output may negatively impact
the performance and recording - think of how distracting it can be to hear your own voice
with a short echo while on a phone call.
Latency is a direct byproduct of sample rate and buffer size settings, so adjusting these
settings in your host application or the audio driver will have an impact on latency.
8.2. Sample Rate
In the digital realm, analog audio signals are represented by discrete points in time, or
"samples". When played back through a digital-to-analog converter, like those in computer
soundcards, the digital samples are reproduced into a smooth audio signal. You can think
of it like frames in a movie - each frame is a still snapshot, but when played back at a fast
enough rate (24+ frames per second) our eyes perceive the sequence of static frames as
continuous motion.
The sampling rate describes the frequency of digital sampling points, or "frames", used to
approximate the audio signal over time. This also determines the highest frequency that can
be captured or reproduced by the digital representation. The Nyquist–Shannon sampling
theorem states that this is equal to 1/2 of the sample rate so, for example, the highest sound
frequency that can be reproduced by a sample rate of 48kHz is 24kHz.
The average range of human hearing is 20 to 20,000Hz (or 20kHz). For most audio
applications we recommend using a sample rate of 44.1kHz or 48kHz. Sample rate of CD-
quality audio is 44.1kHz. Higher sample rates will result in significantly higher CPU usage,
without much benefit to be gained in most circumstances.
Arturia - User Manual MiniFuse 4 - A Quick Primer on Digital Audio
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