FM sounds with SubBoomBass 2

At first glance, Rob Papen SubBoomBass-2 [1] is a traditional subtractive synthesizer, but do you know that it can also produce FM synthesis sounds? The FM synthesis sound types have a lot of punch and are a great addition to SubBoomBass-2‘s sound options. Let‘s dive in!

1 Let‘s go!

As a base we take the standard preset of SubBoomBass-2, which can also be found in the „introduction“soundbank. To create an FM sound, you must be able to modulate the frequency of another oscillator. Also, this modulating oscillator should preferably only modulate the other oscillator and not send its audio signal into the filter. To do this, click on the button of OSC1 that disables sending its signal into the filter. Next, select FM mode on OSC2.

2 Frequency modulation

SubBoomBass-2 has many waveforms and even samples on board, but for FM synthesis we will stick with the sine waveform selected for both oscillators. At a later stage you can try other waveforms, but the results can be unpredictable. So using other waveforms is always trial & error.

It is important that you keep OSC2 at the correct tuning and set the FINE tuning to zero, otherwise you will detune the whole sound. Still, you may need to correct the SEMI and/or FINE tuning because of the FM modulation, but you should start with a correct tuning in OSC2. Next, you need to set how much the first oscillator modulates the second. There are two main knobs for this: the initial „volume“of OSC1 and the MOD knob, which controls the modulation intensity. Both control how much the first oscillator modulates the second. It‘s best if there‘s only one control for this, so we‘ll leave the MOD control at its maximum value and use the volume control of oscillator 1 to determine how much OSC2 is modulated by OSC1.

3 Movement in sound

At this point you‘re probably thinking, „That sounds very static!“To make the FM synthesis option more musically useful, you need to use an envelope to control the volume of this OSC1 so that the modulation is not continuous, but „controlled by timing“. For this we‘ll use envelope 1, which you‘ll find at the bottom center of the control surface. The target is the volume value of OSC1 and the amount knob must be fully open. In this setting, envelope 1 fully controls the volume of OSC1. Set the envelope attack to 0, decay to about 600ms, sustain to 0 and release to about 600ms. Well, this sound is already much more usable!

4 Shaping the sound

Let‘s continue with the sound shaping, and for this we can limit ourselves to 5 parameters for the time being, in order to get a powerful percussive sound. First set the following parameters as you like in the OSC1 section:

A) The SEMI tuning that influences the timbre B) The volume parameter, which also affects the timbre and adds more harmonics. On the envelope 1 side you can influence the sound with the following controls:

C) The decay, which makes the sound more percussive, for example, by setting a shorter time. D) The sustain, it determines the timbre of longer

notes after the decay has done its job.

E) The release and here it is advisable to set it about the same as the decay or even longer. Release always starts working after you release a key on your MIDI keyboard.

5 More expression!

Once you have found a good starting sound, you can make it more expressive with velocity or the use of MIDI controllers. To do this, we use the modulation matrix, which can also be displayed in the lower center section of the SubBoomBass-2. a) The velocity, which is connected to Osc 1 volume, is used to change the sound dynamically. You not only need to set the amount in the Matrix, but also the volume value of OSC1 to find the right balance of using velocity to change the sound.. b) The modulation wheel also works well as an additional expression tool. Also connect it to OSC1 volume to create sound changes while playing. c) The modulation wheel is also cool for changing the parameters of envelope 1. For example, connect it to control the attack. When you open the modulation wheel, the sound gets a slow rise instead of becoming percussive.

6

Other sound shaping options

a) We‘ve just added velocity to dynamically control the timbre, but of course there‘s also a velocity setting in the AMP section that determines how the volume responds to velocity. Again, set this velocity parameter to your personal taste. b) Using the filter from SubBoomBass-2: With the default preset used, the filter is fully open. Instead of using envelope 1 to create the FM sound, you can skip this part (point 3) and use the filter and filter envelope to shape the sound. In this case, by modulating oscillator 2 through oscillator 1, you create a static waveform by changing the volume and semitone of OSC1. c) As mentioned in point 2, OSC1 and OSC2 are both set to the sine waveform, which is a logical choice for generating an FM sound. Feel free to experiment with other waveforms for OSC1 and/or OSC2. And yes, it‘s worth trying sample waveforms for OSC2 as well!

www.robpapen.com