When trying to make your master sound clean, it's a good idea to find and isolate any sources of unwanted noise, such as noise generators, and mute them. Additionally, cutting the side image's low-frequencies, as well as the mids by up to 20Hz can add some clarity to your master.
In an attempt to sound more authentic, some processors offer the option to introduce noise- however, this noise can add up very quickly and can become overbearing with the amplitude of the signal is increased. Turn this function off whenever you come across it if you want a clean master.
Let’s listen to how this added noise is affected by low-level compression and limiting, to hear why it should be omitted from your processing.
If your mix has some background noise during quieter parts of the track, try using a very subtly gate and utilizing the range function to keep the attenuation from sounding abrupt. If you put this at the beginning of your chain, it helps attenuate your noise floor before it’s amplified.
This is a little unorthodox, so let me know your thoughts on using this method on a master in the comments.
Let’s take a listen.
One of my favorite ways to clean up a master is to attenuate the side images' low-frequencies by using a high-pass filter, up to 130Hz at the most. This makes this range mono, in turn reducing clashing amongst the mid and side instrumentation.
Some low-end in the side can be beneficial though, so use this effect on a track-by-track basis.
Let’s take a listen.
Cutting frequencies below 20Hz doesn’t clean up your master in an immediate way, but instead gives you more headroom to work with. This means you can achieve a louder signal without as aggressive of limiting - so this trick indirectly causes a clean master by avoiding aggressive attenuation.
The effect is typically subtle, but it doesn’t hurt to try when mastering.
Let’s take a listen.
Linear-phase processing is somewhat of a give and take - on one hand it creates a more accurate phase response resulting in more accurate equalization. On the other, it causes your DAW to compensate for it’s latency, which can affect your signal’s transients and subsequent impact.
I’ve found a good middle ground to be a low-latency setting, which preserves the phase without introducing noticeable pre-ringing.
Let’s take a listen.
Clarity is often associated with a clean sound - that’s why you need to be careful with which saturation type you use on your master. Tube, although pleasant-sounding, often has a strong second-order harmonic which may be too warm for a clean sound; tape on the other hand doesn’t.
It typically introduces 3rd and 5th order harmonics, with some mild variations from plugin to plugin.
Let’s compare the 2.
If you want to introduce cleaner sounding harmonics, while simultaneously rolling off some low end and adding a little high end, 30 IPS tape emulation is a good option. Due to the speed, low-frequencies won’t be as easily represented, resulting in their subtle attenuation.
This, in combination with the other effects of high-speed tape emulation, often results in a clean-sounding master.
Let’s take a listen.
For some reason, engineers that like dithering really seem to like dithering - to each their own; however, excessive dithering introduces more noise than needed. For example, if I’m exporting my master as 24 bit, dithering noise will be louder than the quantization noise and maybe even the recording’s noise.
Additionally, background noise from your recording or microphone’s electronics can introduce enough noise to perform dithering, so no need to add more noise to your signal.
Let’s listen to what a 24-bit track sounds like with and without dithering.
Aliasing distortion is something to be concerned about when mastering, especially when using aggressive limiting or saturating high-frequencies. To avoid this and the distinctly digital sound this distortion creates, use oversampling, or even better set your session’s sampling rate as 96kHz and combine that with oversampling.
Let’s listen to a 44.1kHz master with no oversampling, and compare that to a 96kHz master with additional oversampling used when available.
