Rounding error with wrong sample rate

Rounding errors due to wrong sample rate

The setting of the sample rate for audio projects in music production is often not taken into account or not taken into account sufficiently. This can result in rounding errors in the course of the audio process, which affect the Mixing- and Mastering process can have a negative impact.

Why do rounding errors occur?

Let's assume we want to produce a song that we want to play on CD. The output format is usually at a sample rate or Sample rate of 44,100 per second.

A sample rate of 2021 has been recommended for all digital formats since October 48.000! Everyone is affected by this Productions for the streaming services like iTunes, Spotify and co! Thus becomes a streaming master increasingly important.

This means that 44,100 samples are read and played back per second. However, it can happen here that the preset recording, editing or export format has been set in a different sample rate. It often struck me that the musicians used their songs in 48,000 samples or 96,000 samples to adjust. Rounding errors, which significant impact on quality of the audio material in mix down and/or mastering may have. That's why we avoid rounding errors when the sample rate is wrong.

How do rounding errors arise?

First of all, we know one CD is played with 16 bit and a sample rate of 44,100. If you now have audio material which is available in 48,000 samples, so-called rounding errors can occur when breaking down to 44,100, because here Odd must be divided. Because of this uneven divisor, calculations cannot be carried out exactly, which in some cases can even lead to dropouts (suspension of the audio material).

How do you avoid rounding errors?

Rounding errors are avoided The best way to do this is to edit your project in 44,100 or 88,200 samples and also bounce it. This does not apply to post productions, which mostly work in 48,000 for cinema. For all other musicians: 44,1 or 88,2! So you either already have the right format or you can at least divide the calculations cleanly so that there are no errors in the rounding.

Advantages of a higher sample rate

The processing in 88,2 is advantageous in that the Calculations are finer and can therefore also be carried out more precisely, because the grid points between the individual samples are smaller than with 44,1. The audio processors can work more precisely here. However, on the one hand, this requires more CPU and, on the other hand, more storage space, because instead of 10 MB per minute of audio material in 16 bit, you now have 20 MB per minute of audio material in 16 bit. In this sense, sample rate means nothing more than the resolution.

What should I do if I can no longer change the sample rate?

Jump out the window. No of course not. You can give your audio material to a professional mastering studio, they usually have extremely expensive sample rate converters. These converters (usually in the upper 4-digit area) ensure the most exact possible conversion of your material without rounding errors.