I know, I know… low pass filter has been around since forever and is FAR from the fanciest effect one can use but hear me out:

One of the most common issues I hear from DAW producers is lack of low pass. Here are 5 simple uses of low pass that you hear experienced producers employ all the time.

You should totally be aware of them.

1: Narrative

Putting real nice low passes on your groups, busses, or even the master and then SLOOOOOWLY opening them up is a fantastic way of adding narrative and variation to simple, repetitive sections. It's a cliche for a reason: it WORKS and crowds love it in a live set.

2: Boosting the highs

Low pass cuts the highs out, right? So why would you use it when you want MORE highs? Well if you set the filter cutoff real high (like 8k+) and then boost the resonance you will nicely accentuate (and phase rotate) the highs around the cutoff point, giving a smooth and creamy boost. You might lose a touch of the high end up past 12k but the creamy texture you gain makes it worth it. I will often use my Analog Heat's physical low pass circuit on the full instrumental and then let the vocal own the "air" frequencies up past 10k. It's a great way to get the vocal to sit on top and in front of the instrumental.

3: Pinging

When you increase the resonance of a filter you're rotating the phase of your sound waves near the cutoff point and at high settings the resonance can cause a ringing decay. If you get a real nice low pass filter and then send it little transients you get these juicy percussive pinging sounds that are deeply satisfying in texture. Make sure you use a nice filter though. It sounds terrible with many digital filters, but totally amazing with an analog filter or an analog modelled filter like the UAD Moog filter.

4: Low Pass Gates

That brings me to one of my favourite circuits in hardware synthesis: the low pass gate. A low pass gate is a circuit where the filter cutoff and VCA amplitude are tied together. Opening the VCA opens the filter, opening the filter opens the VCA. They are one and the same. This means you get highs only on the loud portions of the signal and quieter portions sound more filtered. This emulates the behaviour of many sounds in real life and has a satisfying physical tone. Pinging a low pass gate yields the famous "Buchla Bongo" percussion sound. I love it! You can easily make a low pass gate by creating a Macro that controls both amplitude and filter cutoff and many synths can route a modulator to both cutoff and VCA. Give it a go and thank me later.

5: Audio Rate Filter FM

This is one of my secret sound design weapons, especially when making bass sounds. If you route an oscillator to control the filter cutoff and then juice the resonance you get these gnarly FM sounds that feel much more alive than the sterile Yamaha DX7 type FM sounds that typically come to mind when you think of digital FM. If you make a Reese bass where only one of the detuned oscillators modulates the filter cutoff it sounds totally amazing.

Hopefully these 5 examples will whet your appetite for low pass and get you taking full advantage of one of the most tried and true tools in music production. It's not always about using the most high tech plugins you see advertised on Instagram… the fundamentals are a bottomless well and you can NEVER be too geeked out on them.

Do you have any other uses for low pass that should be on the list? Please chime in with your advice in the comments.

All the best, music makers!

Dylan aka ill.Gates