SYNTHESIZER EXPLAINED: HOW TO USE FILTERS | Sound Design for Beginners (Filter Tutorial)

At the end of this tailor-made tutorial, you will know exactly how to use filters on a synthesizer.

Sound design basics part 2: filters

This is part 2 in a 4-part series where you will learn the absolute essential basics of sound design. In today’s post, you will discover how to use filters. In the remaining parts of this series, you will find out how to use oscillators, how to use envelopes and how to use LFOs.

Why you need to know how to use filters

Just like oscillators, envelopes & LFOs, filters are crucial functions on a synthesizer. If you don’t know how they work, you’re cutting yourself short as you will fail to create unique sounds or special effects. And, this will directly hurt the quality of your music.

That’s why it’s very important to read until the end, so you don’t miss any valuable tips how to use filters to your advantage. Thereby, let’s focus on some of the essential basics of sound design.

But if you want to benefit from a fully detailed step-by-step approach, just get the Sound Design for Beginners guide. Many people have already read it, but if you don’t, click the link to start immediately.

What are filters?

Now, what exactly are filters? Filters are functions on a synthesizer that can enhance and/or reduce certain frequency ranges in your sound. You see, any sound consists of frequencies that your ears can pick up. So, with a filter you can adjust them, which change the so-called “harmonic” balance of the sound.

As you can imagine, this can come in handy to produce a wide variety of different sounds. But if you want to have finished sounds already prepared for you, just get my free sample pack. Just click the link to start your download.

Now, let’s find out about the different settings on a filter and explore how they work. But keep in mind, we’re going to focus on the basic ones only, as that’s all you need to get started.

How to use filter type

Before you can use a filter, you must select its type. The type determines how the filter cuts out or boosts the frequency ranges. In other words, it sets the filtering method, such as low pass, high pass or band pass. These are the most common ones, but what exactly do they mean?

I’ll explain them in a second, but to give yourself a great demonstration, feel free to open an equalizer. An equalizer can serve as a visual tool to show all the filter settings. After all, a filter usually doesn’t have a graphical user interface, while most equalizers do.

Low pass (LP), high pass (HP) & band pass (BP) filters

All right, back to the filter types.

  • A low pass filter, LP for short, removes the higher frequencies from your sound. It “passes” the lower frequencies.
  • Similarly, a high pass filter, HP for short, removes the lower frequencies. It “passes” the higher frequencies.
  • Lastly, a band pass filter, BP for short, removes the higher AND lower frequencies. Thereby, it “passes” a band of frequencies.

Make sure to select your preferred filter type upfront, depending on if you want to remove the lower frequencies, higher frequencies or both.

In the video, I will show you what that looks like on the Sylenth1 synthesizer. Just hoover to the filter section and simply select the filter types.

Now, a filter type doesn’t do anything on its own. To hear an effect, you have to use the other filter settings as well. Of course, it also depends on how you use them. So, stay tuned as I’ll cover them all next.

How to use filter slope

Besides the type, a filter also needs to have a certain slope. The slope defines the extremeness of frequency reduction. By changing the slope, you change how gradual or how abrupt the frequencies should be cut out by the filter.

-12 dB, -24 dB & -48 dB filter slopes

This way, you can usually set the slope to -12 dB, -24 dB or -48 dB, whereby a higher number means a more extreme way of filtering. And vice versa, a lower number means a more gradual way of filtering.

Just as for the filter type, the filter slope doesn’t do anything on its own. It merely sets the initial conditions on how you wish to “filter” your sound. To actually hear an effect, you will have to set a cutoff point. And again, you will find way more details in the Sound Design for Beginners guide.

How to use filter cutoff

A filter uses a cutoff point and/or a resonance peak to define exactly which frequency ranges are affected or amplified. Keep reading as we will talk about the resonance option in a minute, but first, let’s look at the filter cutoff.

The cutoff, or “cut” for short, sets the frequency at which the filter starts working. This way, you can use the cutoff to decide at how many Hertz the volume of your sound should start to diminish. By the way, if you’re not aware, frequencies are measured in Hertz.

For example, if you set the filter to a low pass type and a cutoff point of 2000 Hz, the filter starts to reduce all the frequencies above 2000 Hz and thereby passes the frequencies below 2000 Hz. Of course, the extremeness of reduction depends on the filter slope.

Using the filter cutoff (in combination with the type and slope) finally produces an effect. Yet, you can affect it even more by using the resonance option.

How to use filter resonance

Resonance, res for short, is a special function and how it works depends on the filter type. It either sets the amplitude of a narrow frequency band at the cutoff point. Or, it sets the frequency bandwidth centered at the cutoff point. Okay, that sound too complex. So, let’s simplify.

Resonance with a low pass & high pass filter

If you select a low pass (LP) or high pass (HP) filter type, the resonance will create a sharp volume boost at the cutoff frequency. A narrow bell curve if you will. So, by changing the amount of resonance, you will change the loudness of this volume peak. Thereby, more resonance means a bigger frequency peak and less resonance means a smaller frequency peak.

Resonance with a band pass filter

However, if you select the band pass filter type, the resonance will work differently. It will now give you the option to control how many frequencies should pass. Call it a frequency band if you will with a certain bandwidth. Whereby, more resonance means a narrow band of frequencies and less resonance means a wider band of frequencies. Also, depending on your synth, adding resonance may boost the volume of the band as well.

More filter settings

Depending on your synthesizer, you could find many more filter functions, such as saturation, extra filter types or routing options. But these are for the more advanced individuals among us and lessons for another tutorial.

Today, you’ve learned some of the essential sound design basics, including filter type, filter slope, filter cutoff and filter resonance. But be aware that all these settings work together and depend on each other to create interesting sounds and rich filter effects.

Beyond filters: sound design for beginners

Now, if you’ve learned a lot today, I would appreciate it if you could share this post around, but also you will learn a hell of a lot more from the Sound Design for Beginners guide. It has already helped many producers worldwide to make incredible sounds for their songs. All you have to do is click the link and you can begin as we speak. See you there.

Leave a Comment