Fitting bass boosts around the bass notes
When I’m working on a master for something that someone else has mixed, I frequently need to help the low end. People who don’t yet know how to anticipate what mastering will do inevitably don’t mix or EQ their kick drum properly. So it needs some augmentation.
Mostly this takes the shape of helping the kick speak better in the low end. If the kick speaks properly in the low end, it’ll hit the limiter in a way that momentarily ducks the rest of the mix when it hits, which helps the whole kick drum sound louder, not just the low end of it.
But … where to put the boosts? If you do it wrong, it just makes the low end muddy, and the bass uneven, and it makes things worse, not better.
The approach that I take is to make the boosts targeted and narrow, and to put them between the bass notes.
For example: let’s say that we have a song in C# minor. I was just mastering a song like this today! It also went to the relative major a lot (A major), and the bass touched on some passing notes as well: B, F#, and G#.
So let’s look at those frequencies! They are:
F#: 92 Hz
G#: 104 Hz
A: 110 Hz
B: 124 Hz
C#: 139 Hz
Those are the places you don’t want to put the boost. If you do, you’ll also be boosting a bass note, and uneven bass is something that mastering is intended to address, not to cause.
But there is a wide range of options between these off-limits frequencies! The basic idea is that you want to put a narrow little boost in between the bass notes — and you want to find a boost that works with the tuning and impact of the kick drum.
For this song, after some experimentation, I put the primary boost at 116 Hz. That’s pretty high for some types of kick drums, but this was a dance remix with a 909 type kick drum, and it worked. If the kick drum were tuned lower and I had wanted a lower boost, I could’ve done something somewhere in the 96-100 Hz range — there’s plenty of room in there with a song in this key.
These are generally Q=4.0 boosts, by the way — with as much gain as needed to help the kick hit in the way it wants to, which is sometimes +4 or even +5 dB. If I’m trying to sneak a boost into a tight place, or if Q=4.0 just sounds too broad, I might narrow it further to Q=5 or even 6. Use your ears.
And then, often, I will pair this primary boost with a secondary boost an octave down from the primary boost, for solidity and grounding commensurate with the sense of size and space conveyed by the primary boost. So in my case today, that meant a second q=4.0 boost at 58 Hz.
Knock knock — jamie
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