Audio downsampling is the process of reducing the sample rate of a signal, meaning it reduces the amount of data in an audio file. This process is usually done to reduce the file size or to transfer the audio to a system that records or stores data at a different sample rate.
When a signal is downsampled, it maintains the length of the signal with respect to time, but it removes some audio information. Downsampling is commonly used in music production to achieve a low-fi sound that can be desirable for certain genres.
The Downsampling Process
The downsampling factor is usually an integer or rational fraction greater than one. The signal processing algorithm reads the audio signal and removes certain samples. However, when reducing the sample rate, the process of interpolation is required. It creates sample words at the new sampling rate that are “in between” the words at the old rate. Different types of interpolation process can add noise or “gritties” to the sound, depending on how it is done. Some samplers allow the performer to bypass the anti-aliasing filter, so that aliasing is intentionally created during downsampling.
If the target sample rate is above 44.1 kHz, you don’t need to worry about the audible range. A suitable resampling tool will result in almost no additional losses.
Conclusion
Audio downsampling is a useful process to reduce the file size or transfer audio to systems that use different sampling rates. Although downsampling removes some audio information, it can also be used as an effect to achieve a low-fi sound. Knowing the downsampling process can help you understand how to create the best quality audio for your needs.
FAQ
Why is downsampling done in audio production?
Downsampling is done in audio production to achieve a low-fi sound that can be desirable for certain genres.
What is the downsampling factor?
The downsampling factor is usually an integer or rational fraction greater than one.
How does downsampling affect audio quality?
Downsampling removes some audio information because of the reduction in sample rate, which can affect the overall quality of the audio. However, if the target sample rate is above 44.1 kHz, a suitable resampling tool will cause almost no additional losses.
Final Thoughts
Understanding audio downsampling and its effects on the audio is essential in producing high-quality audio. By knowing the downsampling process, you can manipulate the audio to achieve the desired outcome and avoid any unintended audio degradation.
