Dithering has become very common in music production. It is a technology being used during the mastering process to increase audio quality.
What is Dithering?
Audio dithering is the technique of adding low-level noise to particular audio. For you to get an in-depth understanding of the topic, you need to be conversant with terms such as sample rate, bit rate, bit depth, and dynamic range.
If you have been doing music production for some time, then the term may sound familiar. This is because it is usually an option whenever you are exporting your DAW. Sometimes it is available as a plugin that you can use for mastering. It all depends on the platform you use to master your music. What makes dithering unique from other functions in music production is that it doesn’t have a discernible effect.
That is why you will find that some of the most renowned music producers don’t even know what it is. The few who know about dithering have no idea where to use it and when.
Is Audio Dithering Necessary In Music Production?
The fact that adding dither adds noise to your music might sound more of a disadvantage than an advantage. But no, dithering is very important when mastering your music. It mostly comes in play when dealing with production errors such as quantization. The low-level noise that dithering introduces ends up masking the quantization error, which occurs after changing your bit depth from high to low.
In case you have no idea what is quantization error, this is the truncation of audio files at the lower bit and to be precise, this tends to happen at bit rates of 16 bits that have not been dithered. The decay tail of audio with a low bit depth tends to stop without warning, and this causes the audio file to be less smooth and irregular. It’s what is referred to as quantization errors.
It means that when you are working with an audio signal that has a low bit depth, you need to dither. If you don’t perform dithering to this kind of sound, the encoder can decide to switch the bit off or on. So in the end, the resultant sound will be a bit fuzzy and inaccurate. The introduction of the low-level noise tends to scatter throughout the sound spectrum to prevent sound irregularity.
It also ends up re-establishing the accuracy of the audio sound you are producing. That’s why dithering is important.
When do I Need To use Audio Dithering?
Before going into the details of when to adding dither, you need to understand the relation between bit depth and audio quality. The quality of sound is dependent on the number of bits it contains. This means that any bit added to audio tends to increase its quality a great deal, and so does the accuracy. That is why music producers always focus on the bit range whenever they want high-quality audio.
You should, however, know that the higher the bit depth, the bigger the audio file. It means that if music producers were to maintain the bit depth, there would be no music CDs because the CDs have a lesser capacity. That’s the reason why music producers are converting to mp3 to a size that can fit in Compact Discs.
This means that if you are recording music at high bit depth, dithering is not necessary. You are also advised that you maintain your recording bit depth and only down-sample it if you have no otherwise. If you want to record then send your audio to your sound engineer to master in case of a collaboration, don’t perform dithering.
Almost all modern limiters include dithering option (Image of FabFilter Pro L2)
Why? Because you should dither your audio once, and that is when you are down-sampling your audio. Since the audio will be down-sampled by your sound engineer, let him, or her do the dithering. You should also communicate so that he or she knows the music has not been dithered.
You can also apply for dithering when you are exporting audio files from your DAW to other external devices such as MP3 player. Dither only once during export. However, this is to avoid adding too much unnecessary noise to your music. Ensure that you don’t dither any files that have a float of 32 bit. Instead, dither when bouncing audio files. But make sure they have the same bit depth as the one you have finished recording.
As mentioned above, some DAWs will bring up the dithering option when doing a conversion while others have it as part of the plugin. You should thus understand the DAW you are using and where to get the dithering option before you continue.
Why Do I Need To dither?
After you’ve done with your composition, you will want to share it with your fans so that they can listen to your creativity and enjoy your music. The problem is, you cannot share the file in the same format that you created them. This might be 32-bit float or 24-bit float. You will thus have to sample-down the music to 16-bit float before putting them in CDs and other devices. If you don’t dither, your fans will end up listening to quantization errors available on your music.
They will be noticeable because the music is in a low-level format. To cover up the holes and irregularities that are as a result of quantization, you will have to apply dither. That is why you need to dither every music you produce during conversion. Remember, the noise is usually unrecognizable so for you to know what dithering sound like, you will need to normalize your audio to 0dB.
Difference between dithering on and off
Just like the name suggests, dithering on is the inclusion of noise to your music while dithering off is the lack of noise on your sound. When the dither is on, your music will become very smooth, and this will make it much better. Once the dither is off, there will be irregularities. Dither on when down-sampling and dither off when using audio with a higher bit rate. The type of DAW you use doesn’t affect the effectiveness of your dither. Given that dither is a type of noise, make sure that you apply it only once.
To understand the big difference between dithering on and dithering off practically, you will need 24-bit audio with a bit rate of about 88.2 kHz. When you import it to your favorable mixing software, you can increase its bit depth to about 32 bits. Also, it will enable you to achieve optimum mixing. Once you are done with the processing, down-sample your bit rate to 44.1 kHz, you can listen to it at 0dB and experience complete silence.
Go ahead and dither down your music to 16 bit while maintaining the same bit rate of 44.1 kHz. Play it at 0dB, and you will hear the hashing noise. Play the music and feel its smoothness while comparing it to the audio that is not dithered.
You can only shift options if you are well conversant with the dithering option, else, you risk to distort your audio.
Some Of The Dithering Options Include:
• Amount; this signifies the quantity of noise being added to your music. Too much noise will destroy your music. That is why using as minimum noise as possible appropriate.
• Limit Peaks; this option is used to suppress the peaks of dither that has an aggressive noise-shaping.
• Shape; this is a dithering option that determines the shaping of the noise. There are two options, ultra and none. Ultra noise shape has a more drastic curve. None, on the other hand, is entirely flat.
• Auto-blanking; this option enables muting of the noise anytime the audio goes silent. The listed amount of time muting can be done is 0.7s.
• Suppress harmonics; this selection is suitable for someone who wants to paralyze the effects of truncation to some extent but without using dither.
• Limit Peaks; you can only use this option if you have used the shape option. The reason is that it’s designed to reduce the peaks of an aggressive dither.
From the information above, it is evident that dithering your audio is one of the best ways to achieve smooth music. Rather than distorting your audio, dither makes it regular and thus increases its quality. The option is used to do away with quantization error. You should, however, keep in mind that you only have to dither once and that is when sampling-down your music.