The lower end of mixing can be the biggest battlefield for mix engineers. Almost every track can contribute some sort of low frequency energy that can easily clutter up the sound and eat up your headroom in a flash! What you allow into the lower region of your track can determine the overall result of the entire mix!
As previously stated in the first part of this series, the use of filters is imperative to maintaining a manageable low end – filtering out 100Hz and bellow on anything that doesn’t need bottom end will help you to maintain control over what contributes to the low end of your track. Be cautious when boosting low end if your monitoring system doesn’t translate information bellow 50Hz well, as this is a quick way to make your track too “boomy” and not translate well to other systems that can convey low-end information well.
There are no hard rules about how much bass is too much bass; we do however have existing successful commercial material to give us an indication of what we should be aiming for when it comes to the sonic quality of our mixes. I would highly advise importing several commercial tracks that fit stylistically with the sound that you are trying to achieve. Switching back and forth between your mix and other professionally mixed songs will be your greatest guide to achieve a well-balanced tone that translates well on every sound system.
Remember to be well aware of what tracks are contributing to the low end of your track. Multiple kick samples, electric bass, synth bass, synth pads and even vocals carry many subsonic frequencies that if not layered appropriately, can lead to a low end that is overbearing and muddy (this is where HPF’s are necessary). Try to use only one sound source that carries the sub sonics of your track, you can then use other bass sounds with heavy HPF’s on them to layer on top of your sub bass sound and thicken up the overall texture of the bass sound. Also be mindful of having both a very “subby” kick and bass sound, it’s usually one or the other, having both at the same time is almost counter productive to your song.
Another very important aspect of mixing multiple low end sources is phase and time alignment, this is where referencing in mono comes in very handy. Solo all of the tracks that are contributing to the lows of your track, if when you hit the mono button you suddenly lose a lot of low end, then you will need to invert the phase of some tracks, using a phase correlation meter (found within most metering software) is very at this point – ensuring that you’re phase is positive and not in the red.
Zooming in and using your eyes will help you to determine which tracks need to be fixed, but remember to always trust your ears, and not your eyes. If you are aiming for your tracks to be played on nightclub systems, bear in mind that most club PA’s subs are actually wired in mono.
Having a bass sound cut through your song can sometimes mean you need to boost the top end of the sound, which I know sounds contrary to what we’re aiming to achieve here, but a boost in top end can help to allow your bass part to have definition and translate well on smaller systems. The 1Khz midrange is a good value to boost, as it doesn’t add extra mud to the low end, and doesn’t add harshness to the upper mid side of the sound. Distortion is also an invaluable tool to help add harmonics and layers to your bass sound, helping it to cut through with power, aggression and character.