Circle Tutorial 5 - Creating a High Passed Riser Effect

What is Covered?
An intermediate level tutorial on creating a high passed riser effect
Introduces the design of sound effects and how to create movement in the sound over time using modulation.


Lets take a look at another effect, this time incorporating a high pass filter and multiple LFOs. This time we will create a riser effect that would be useful when creating tension in your arrangements or filling a breakdown that connects two segments of a track.

Once you have built one sound like this, it opens a universe of possibilities for creating many more. it's always useful to have a bank of patches in this vain so that you can easily grab one when building your arrangements. Let's get into the programming of the effect and see how this sort of sound is created.

Step 1 - The Oscillators.

For this patch I have opted for a simple set of oscillators due to the body of the sound being made up of modulations and effects. I have chosen an analog saw tooth and a noised based oscillator. This may seem minimal but you will soon see how we can build the sound up using creative routing.

Saw tooth, noise and feedback.

There is also a touch of feedback dialled in and the whole thing is mixed roughly in Circles mixer section.

The mixer.

The raw oscillators.

Step 2 - Setting up the high pass filter.

This sound is based around a high pass filter. This simply means that the filter will cut the bottom end using our chosen curve (in this case we are using the 2 pole model). It works in exactly the opposite way to a low pass filter. I have performed a manual sweep so you can hear the filter in action with our raw oscillators.

The high pass filter in action.

The raw oscillators.

Step 3 - The envelopes.

In some of the previous tutorials the sounds have used the LFOs as their main modulation source, in this case the work is split pretty equally between the LFOs and envelopes. The two envelopes are set to pretty similar values but with slight differences in timing and curves..

The envelopes.

The firstand perhaps most important routing of the envelopes is to the main pitch of the saw wave oscillator. This creates a dramatic rising effect and will be the foundation for the entire sound. Notice that this oscillator has also had its keyboard tracking turned off, this means that the pitch will remain the same regardless of the key that is played.

The rising saw wave.

The first envelope also effects the level of the feedback oscillator. This will ensure the feedback effect slowly fades in as the sound develops.

The rising saw wave.

The two envelopes also have influence over the filter here. The fist controls the amount of resonance added over time, while the second controls the cut off frequency. This adds yet more emphasis to the rising effect we are aiming for.

The filter is also modulated by the two envelopes..

The envelopes are applied.

Step 4 - The first of three LFOs.

There are no less than three LFOs being used in this patch but in reality this first LFO is doing most of the work with the other two providing back up duties. The first LFO is using a very simple sine wave based waveform and is running at an average speed. The real trick here is that its rate is being modulated by one of the envelopes, so that it gradually speeds up over time.

I wanted the LFO speed to go from slow to extremely fast and the only way i could achieve this was by layering the same modulation source on the LFO rate slots three times. The third is actually not at its full amount but this really seems to work for achieving intense modulation effects.

LFO 1 using the triple modulation trick.

The filter frequency is then linked to the LFO to create an intense effect as the sound rises. The LFO and filter effect then slow as the key is released.

LFO 1 modulating the filter cut off.

The sound modulated by the main LFO.

Step 5 - Extra LFOs and modulated effects.

To finish the sound off some extra touches were added. Two more LFOs were called up, both with fade ins and delay. These will not come into action until the sound has nearly completed its rise.

Two more LFOs.

The first of these two extra LFOs is modulating the feedback generators pitch, this adds a subtle change as the sound develops and makes the patch feel as if it is evolving slightly.

LFO 2 modulating the feedback tuning.

As is often the case in Circle patches the thing that really finishes this patch off is the application of effects. A panner, delay and reverb are used here and all of them are modulated in some way to add movement and depth.

The mix levels of both the reverb and delay are modulated by a rising envelope and the panner is modulated by the third LFO, creating a delayed autopanner.

The modulated effects.

The final patch.

Final patch with LFOs and effects.

Download Tutorial 5 Files

Tutorial 5: Creating a High Passed Riser Effect
Download the tutorial in plain text format, the associated audio files and the completed Circle sound/patch.