Although it's quite easy to amass thousands of drum samples through the Internet, it can be fun and rewarding to make your own entirely from scratch. Sytrus is a good choice for this, with it's flexible oscillators and precise envelopes. In this tutorial, we'll use Sytrus to construct a simple electronic kick drum sound.
Open Sytrus and access the presets list from the drop-down menu in the top left corner. Find the preset called 'Default' and click on it. This is an initialized patch and the best starting point for a new creation.
Program a little rhythm with the step sequencer. If you press play, it should sound annoying. To make it less annoying, navigate to the first oscillator by clicking the 'OP 1' tab at the top of Sytrus or either of the squares labeled with the number one on the sides of the matrix. Drag the 'Freq ratio' of the oscillator down to zero and the 'Freq offset' up to around where you want the kick drum's fundamental frequency to be.
Now the pitch should be better, but it still needs to decay like a drum, instead of sustaining all the time. Staying in the first oscillator section, make sure the 'Editor target' is set to 'Vol' and the 'Articulator part' is set to 'Env', which is how it should be by default. Click the circle at the bottom left of the envelope to enable the volume envelope and start dragging the envelope breakpoints around, making sure that it starts with a instantaneous attack and the sustain point, labeled with an 'S', is at the bottom.
It should sound something like this.
Set the 'Editor target' to 'Pitch' and stay on the envelope articulator part. Enable the pitch envelope by clicking the circle in the bottom left. It should sound ridiculous. We want the pitch to descend quickly. Delete all but two of the breakpoints by right-clicking them and selecting 'Delete'.
With your two leftover breakpoints, drag the first upwards and the second down, so that together they make a downward slope. Adjust the tension between the two breakpoints by clicking and dragging the small red circle between the yellow breakpoints. You can adjust how much the envelope affects the pitch of the oscillator with the 'Pitch envelope' knob, labeled 'PE' in the top right of the oscillator section.
This is an example of what the pitch envelope knob will do.
Now tweak the envelopes until it sounds right. If you would like to add even more to it, trying using more oscillators, enabling them by finding the knob under the 'Out' column and in the oscillator's row and turning the knob right. With these exta oscillators, try adding different, higher frequencies along with the fundamental or mixing some white noise in with the fader labeled 'NS' in the top left of the oscillator section. Use the pitch and volume envelopes in these oscillators in the same way as the first one.
Here's what I came up with, in the end.