Sub bass tip 2: getting sub frequencies right in your mix

Here’s a thought relating to sub bass frequencies in bass music – i.e., music where the sub bass usually sits below the kick on the frequency range (e.g., drum and bass) or fairly close to it (tech house etc).
This doesn’t apply to genres such as rock or house, for example, for there you may have your kick lower than your bass in general.
Also in genres like tech house, sometimes the bass *may* live a little higher than the kick, but there definitely has to be sub frequencies for the song to work and have energy.

In a nutshell, we want to have our sub strong enough around 40–60 Hz area, because that’s where the meat is. ”Strong enough” is subjective, of course, and there’s definitely variation how loud one likes his sub, but here’s a general guideline, from the perspective of someone who does mixing and mastering every day, that’ll help you have the bass energy in the right place at least.
However, I'd say that 40 Hz is too low, almost, and many systems cannot produce that, and even if they can, it'll sound "sleepy" in terms of energy.
I'd say around 50-55 Hz is as ideal as it gets.

So, you need to have your fundamental frequency in the right area, and that’s around the aforementioned 40–60 Hz range. In simple terms, fundamental frequency means the lowest peaking area in your mix, and we’re aiming at having it within that area, roughly.

With the right tools, it’s very easy to see where it is in your mix. Especially if you don't have speakers that can produce good sub, learning to look at it is essential!

In both pics, you see Voxengo SPAN, which is a free plugin and just great for seeing where the fundamental is hitting in your mix (I’ve set “slope” in SPAN to 4.5, which makes the curve look somewhat natural in my eyes).

Pic 1 shows a D&B track that has its fundamental frequency peaking around 55 Hz. That means there is energy in the right place, and in mastering, that can be boosted somewhat easily, and we’ll have a solid low end.

The problem arises if the fundamental is too high – see pic 2 (this track is quieter than pic 1 but that’s irrelevant in terms of seeing the fundamental). That shows a track that was sent to me for mastering.
The track is pretty strong and doesn’t sound too light, but it’s very “boomy”, for the fundamental is happening around 100 Hz, which is too high to be a sub, and there is a lot of kick energy around that area as well, which means that if we cut that area, we’re going to lose some of the kick, too, which is not what we want, and we’d end up with a master that does not have enough power.

In mastering, pretty much any problem can be addressed, but they can’t always be solved – this is case-specific.
In mixing, one can address this more.
However, this tip is so you can avoid all these issues early on in the sound design stage. When you create a sub that has the energy in the right place, one only has to control its amount.
If it's not there, it can be close to impossible to fix (although I've successfully added sub to basslines/mixes where the bass has been too high using tools such as MBassador by Melda, or bx Subsynth).

Where should the kick live then? This depends on the genre and your preferences.
At least when you have your fundamental right – and your kick above it.
*Ideally* your kick would be an octave above your sub: i.e., if your sub is hitting 60 Hz, try having your kick hit 120 Hz – you’ll make sure the main building blocks are in the right place.
I can guarantee this'll allow for very loud masters as it completely eliminates the fight for bass space, which is pretty much reason #1 in terms of distortion when trying to go loud.
However, like I said earlier, esp. in tech house, kicks often hit lower.
But take this as a guideline, and at least don't let the sub from the kick clash with the sub from the bass.

How loud should the sub be? I'll tell you about that soon in the next episode ;-)