Sub bass is an unavoidable component of many contemporary electronic music genres. However, a good sub still often requires complex and challenging production techniques in the context of the home studio. The main reason is that many “bedroom producers” operate in less than ideal acoustic conditions and, presumably, small monitoring systems. The spectrum of sub bass frequencies extends from 20 Hz to 60 Hz. Although the lowest frequency audible to humans is around 20Hz, sub bass is rather felt, more than heard. Regardless, it’s an important component of a well-produced electronic music track. In this article, we show a few tips and tricks to achieve that rumbling sub bass and shake the club.
The key is important
As you are probably aware, pitch, key, and frequency in this context are all different names for the same thing. Knowing this allows you to understand what frequencies you are triggering when operating in the low-frequency range and how this relates to your track. For maximum impact, the sub should reinforce the key of the song. When working with this, a spectrum analyzer is a must-have tool. Also, handy key charts are available on the internet that will show the exact frequency of certain keys, and notes. This will save your time when working with an EQ and determining where your sub bass should have the most energy.
The importance of high-pass filtering can’t be overstated. In this context, it’s all about eliminating useless low-end information from other instruments than the sub bass. Instruments to keep in mind for this processing are vocals, drums, keyboards/synths, and even sometimes the kick and bass guitar. In a few words, giving your subs a place to live in the mix is crucial. The most critical frequency range is 40-60Hz, so use a spectrum analyzer to inspect this region and ensure that nothing unnecessary is present there.
An extra sine wave is always useful as sub bass
A basic sine wave, either on its own or layered an octave or two below the higher bass notes, is a common way to generate sub bass. Many iconic tracks of genres like drum and bass and techno, were created with Akai samplers’ default load-up sine wave preset. The sine wave is extremely powerful, and it’s pure bass information at low octaves. So, if you already have a bass preset you like but think it needs a little more power, consider layering it with a sine wave and mixing that in with the original. You won’t be disappointed!
It’s a popular technique to use a sidechain compressor to reduce the volume of the bass or sub bass when the kick hits. The only issue is that this ducks the whole signal. Using a multi-band compressor allows us to more accurately target the frequencies we want to be ducked when the kick hits. This, in turn, allows the impact and presence of the sub bass to be still prominent in the mix. For instance, we can set the multi-band compressor such that whenever the kick is triggered, only information below 70Hz. Aim for a fast attack and release, and experiment with the threshold and ratio settings. Listen for clicks, solo your bass, and fine-tune to make it super-tight.
Limit the sub bass
Limiting your sub bass before it hits the master bus channel can be a good idea as well. It’s a fact that the volume of your sub bass’s sound will change as it plays different notes. To achieve a consistent volume, you can use any limiter, and crank it up until you see a maximum of 6dB reduction, for starters. Now pay attention to the result. Your bass notes should sound balanced and pretty much equal in volume.