Audio Channels in Digital Music Production

Digital music production is an intricate process. There are many things to account for, which includes the audio signal. This process includes how digital audio passes through audio channels. Even more, it’s important that an audio engineer or producer understands the best quality audio for their session. So what exactly are audio channels, and what’s their importance to audio producers and engineers?

What is Digital Audio?

First of all, digital audio is sound that converts into a digital form from analog signals. This term covers the process that audio producers and engineers use to modify and record sounds. The analog electrical signal makes up the initial sound when it comes to music recording. These sounds come from various sources. For example, the signals can come from vocalists or musicians.

Digital Music Production and Quantization

An audio producer or engineer uses analog-to-digital converter (ADC) devices to create quantization. Quantization removes the voltage of the sound. As a result, this process assigns a binary number to each amplitude. The individual samples in an audio file are referred to as sample size.

This data is then stored on physical storage, which includes hard drives, CDs or tape. During playback, that data is recalled from storage and is sent through a digital-to-analog (DAC) converter at the same rate that it was recorded. Those numbers translates to a voltage, which then passes through an amplifier.

Pulse Code Modulation

Pulse-code modulation represents analog samples in digital form. An application utilizes this method and encodes raw data. There are two properties to a PCM stream. As a result, these two factors influence the fidelity of the analog signal. The first factor is bit depth, which determines the digital values for a sample. The second is the sample rate, or number of times per second that samples are taken.

Similarly, an audio producer or engineer understands the best sample rate for recording. The audio producer or engineer also takes great care of the track. In addition, the audio producer or engineer eliminates any noise and distortion with analog audio. As a result, the sound can be accurately reproduced.

Audio Channels, Explained

An audio producer or engineer understands the importance of audio channels. An audio channel is the passage that the audio signal travels through. For example, a microphone creates one channel of audio. An audio channel also refers to a signal on physical media.

On playback, the digital audio becomes two audio channels that plays out to a listener. For example, one of the most common playback methods is through headphones. One channel plays the audio for the left ear, the other for the right ear. This is known as stereo, which is the standard for digital audio recording.

Audio Channels, Sample Rate and Resolution

For CD audio, the sample rate is 44,100 samples per second. The resolution that comes with each sample is 16 bit. This describes the amounts of bits present in each sample.

Other sample rates in digital music production are as follows:
  1. 48,000 samples per second (48 kHz): used for computer audio but also for audio that will go onto DVDs.
  2. 96,000 samples per second (96 kHz): used for high-resolution audio.
  3. 192,000 samples per second (192 kHz): ultra high-resolution audio.

An audio producer or engineer understands that human ear can hear from 20-20,000 kHz. Therefore, the frequency of the recorded sound should at least double that rate. At this stage, an audio professional makes use of audio compression.

Lossless compression allows for the audio signal to maintain integrity. An audio channel with lossy compression loses some of the original information.

Audio Channels and Output

Stereo audio channels are widely used and understood, but there are others in the recording and playback process of digital music production:

  1. 4.0 surround sound is where four audio channels deliver audio signals independently or in combination.
  2. 5.1 surround sound utilizes 5 main audio channels plus an audio channel represented by the “.1”, which is designed for subwoofers.
  3. 7.1 surround sound is similar to 5.1, but adds two more channels which are meant for side speakers.

An audio producer and engineer creates the output for these audio channels through sound cards and other programs. This allows the observation of the sample rates. The audio signal issues through another low pass filter. Afterwards, the signal is delivered through the speaker.

Conclusion

Understanding audio channels is complex, yet necessary to delivering great audio quality. A skilled audio producer or engineer understands the relationship between sample sizes and quality in a recording session.

Want to Learn More?

Knowing how audio channels work in digital music production is separates audio professionals from the hobbyists. Audio producers and engineers work with audio channels and other recording elements to bring forth their creative vision. If working in the music industry as a producer or engineer interests you, take a moment to check out IPR IPR’s Audio Production and Engineering Program.

Contact us today to learn more about starting a rewarding career in the music industry.