A Practical Guide to Using High and Low Pass DJ Filters like a Pro & 2 Ways To Apply to Your Practice

By /
A DJ at a mixing console applying the DJ filter effect

In this article we will explore the technical aspects of the most common feature of a DJ mixer and tool for the modern dance music artist: the filter effect. While there are many DJ FXs, specifically, we will explore high and low pass DJ filters, an intuitive explanation to grasp these effects and then practical uses while DJing. If you’re learning to DJ and want to gather the confidence to apply these tools in practice effectively, keep reading.

What do DJ Filters do exactly?

Any beginner DJ will immediately recognize the filter effect on use, however, they won’t be able to describe exactly what it is doing. A filter is a DJ effect (aka. “DJ FXs”) that acts as intentional barrier that prevents signals of a certain frequency from passing through a channel. You can think of it like a kitchen sieve or obstacle which blocks traffic flow in the street. DJ filters are used to cut out certain frequencies above or below a threshold value.

There are two basic filters types on DJ mixers: High Pass and Low Pass. You often see these on a DJ mixer such as the Pioneer DJM-750MK2 or DDJ-400 controller.

High Pass Filters

A high pass filter allows sounds above a certain frequency value through. The analogy you use for a high-pass filter is the height requirement for a rollercoaster ride. Unless a sound is “tall enough” in terms of frequency, the filter will block it out and prevent it from being heard. In other words, high frequencies are allowed to pass.

A title reads "High Pass Filter", with a subtitle "learningtodj.com". There are three columns. The first column shows a rollercoaster ride with patrons speeding down the tracks. The second column shows a sign that says "STOP You must be at least 5kHz" with a line indicating the height requirement and hand pointing down. The third column shows two people: a child and a man with a height chart in the background. The boy does not reach the 5kHz height and so is blocked from the rollercoaster. The man is about 10kHz tall and so is allowed.
A high pass filter prevents frequencies which are too small from being permitted through.

Example

Let’s listen to an example of a high pass DJ filter being applied to a drum track. Initially, the drum track has no filter. Then we will apply a filter will remove frequencies below 5 kHz.

You can hear that frequencies above 5kHz are allowed through once the filter is applied, meaning mainly high-frequency instruments such as high hats are audible whereas kick drums embodying lower frequencies are lost.

Low Pass Filters

A low pass DJ filter allows sounds below a certain frequency value through. It is the opposite of a high pass filter. The analogy you use for a low-pass filter is the height limitations for trucks driving under bridge. If a sound is “too tall” in terms of frequency, the low pass filter will prevent. In other words, low frequencies are allowed to pass.

The title reads "low pass filter". There are three columns. The first column shows a card with a label "small enough to pass". The second column contains a tunnel with a sign. The sign is a large do not permit symbol with the sub-text "over 5kHz". The third column contains a height scale vertically with 0 Hz at the bottom and 20 kHz at the top. There is a truck which is taller than 5kHz and a large X indicating no passing is allowed.
In this example, the low pass filter only allows sounds below the frequency threshold of 5kHz through, meaning the truck is prevented from passing.

Example

Let’s listen to an example of a low pass filter being applied to the same drum track. Initially, the drum track has no filter. Then we will apply a filter will remove frequencies above 5 kHz.

Once applied, the filter prevents frequencies above 5kHz from being heard. Unlike the high-pass filter, the boomy kick drums are preserved where as high hats are lost.

What are the main parameters for filters?

If you want to learn to DJ or are learning to DJ, you need to go beyond the framework of “turning this knob makes the song sound different”. Understanding the technical aspects of what a given DJ mixer feature is doing from a signal processing perspective can go a long way. While filters can come in various levels of complexity, there are two main parameters that are important for DJing.

image 17
  1. Frequency Threshold (or “Cut Off”): This is the frequency level for which the filter will permit or block signals from being heard. In the case of a high-pass filter, all frequencies above this threshold are permitted. In the case of a low-pass filter, all frequencies below this threshold are permitted. The lower or higher the threshold the more signal will be cut from the channel output.
  2. Resonance (or “Q”): This is the level of amplification to frequencies around the the threshold. The Q level can create an aesthetic taste and texture to the filter application. Higher resonance values cause the application of the filter will be more present and audible than in lower resonance values.
A title reads "Filter Parameters". There are two columns. In the first column is a knob labeled resonance with two spectrograms depicting the minimum and maximum states of resonance. The minimum application shows a flat envelop line which descends around the 18kHz mark. The maximum application shows a large peak upwards before the envelope descends around the 18kHz mark. The second column contains a label "threshold" with 0Hz at the 7 o'clock position and 20kHz at the 4 o'clock position. The knob is turned to 9 o'clock and the effect is demonstrated in a spectrogram below it. The line is flat until it reached the 1kHz mark at which point the line descends to negative infinity.
Resonance controls the level of “ringing” or volume amplification around the filter cutoff. Threshold controls the barrier position in terms of frequency.

How do you use filters when DJing?

Filters are effective tools for creating space, similar to EQ or using Reverb, when performing a transition. They can also be used to create and release tension in a track adding intrigue and variety.

Creating Space for Transitions

When performing a transition from one track to another, using a high pass filter to cut the low end of the incoming track can be an effective way to introduce the transition without unloading the energy of the second track immediately. Gradual removal of the filter effects rolls off more of the second track giving it greater presence while offering the opportunity to slowly begin removing elements of the first track.

Adding Intrigue and Variety

Many DJs, especially when working with high-tempo genres that have a great predictability and minimalism such as Tech House or Minimal, can use filters to create variety and intrigue amidst an 8 to 16 bar loop.

Try playing a single 8 to 16 bar loop twice. Halfway through the second repetition apply a high or low pass filter for 2 to 4 bars and remove the application. This single application of the filter has now turned two 16 bar loops, psycho-acoustically, into a 32 bar loop by creating variety.

Want to go deeper?

Checkout our comprehensive beginner to intermediate house / electronic / techno DJ course:

Related Posts

Scroll to Top