We’re going to motor on to our next “Under the Hood” patch for Dexed, so let’s pull the synth into the garage and get started. Our “Under the Hood” series is a group of tutorials on Pro Sound design in Dexed. In every one, we give you pro sound design tips for Dexed from commercially available sounds. Today’s sound, from SoundEngine’s Flywheel patch bank, cart 1, is Swipher – a rather odd, nasal, swept filter attack synth – but definitely with the dynamic response of an FM sound. Flywheel is our combination bank of analog emulations and painfully edgy FM sounds, and Swipher is in the “analog emulation” category.
Keys in the Ignition …
Let’s select Algorithm 8 for this sound. It offers two sonic pathways—one that will be our base tone in the voice and the second that will add our swept filter effects through the modulation of OP3. Turn off OP3 for a moment, so we only hear the audio defined by OP1 and OP2. We’ll initially set both frequencies of OP1 and OP2 to f=1 and adjust the OP2 level. Set the Feedback for the Algorithm to 7.
The EGs for the OP1 and OP2 levels should be set to 99 for all of the steps. Since OP1 manages the output of this audio path, we can slow the attack rate to 55, which affects the overall sound.
Issues with the Dexed UI
One of the things we need to observe and manage in Dexed is that there is a disconnection of sorts between some of the values shown in the editing status in the lower left corner of the display, and the knobs. This sound demonstrates this well. What I mean specifically is that there are more steps in programming a knob than are shown while you edit.
What we want to do here is adjust the output level of OP2. If you click on the OP2 level and move the knob, you’ll see values for OP2 OUTPUT LEVEL vary between 0 and 9. Sonically, however, as you play notes and move that knob, you will clearly hear more than 9 steps. With that detail noted, I’ll say that it’s always good practice to continually audition while designing a sound – play a note on your keyboard or click on the keyboard of dexed, but listen to every minor change.
The output level of OP2 is particularly important for the tone of this audio path, so carefully dial it down from the maximum “knob full right” position. I count as 15 steps to the left for my target. This will report a value of 8 in the display but produce a semi-pulse waveform as in this oscilloscope screenshot.
One final step for this audio path is to modify the Tune of OP2 to f=1-7. This detunes the OP so that we achieve some chorusing that thickness in its output. Another trick is to program differing release times between a carrier and modulator so you hear differences in modulation upon key release. Here, I’ve programmed OP2’s release rate to 51, while OP1’s release rate is slower at 43. This offers a bit of interesting modulation that you can wear during the release phase of the sound.
Start Me Up!
Let’s grab the spanner and work on the second audio path. Turn on OP3 – this is the primary operator that contributes to the audio output, in addition to Operator 1. We are using the OP3 audio path to achieve the dynamic, harmonic-rich modulation that “Swipher” generates at higher velocities. The steps to that, at a high level, are:
- Program the Operator Frequencies, adding a little detune for motion and thickness
- Program the velocity response for each operator.
- Adjust the output levels of each Operator
- Shape the primary Operator’s output (Operator 6) via its EG
I’ve included both the final patch and a screenshot for your reference along the way. Detune Operators 4 and 6 to -7 and +7, respectively, to add motion to the audio path. Operators 5 and 6 have been programmed to add some nice harmonics with their additions.
Modulation Driver
The velocity responses are somewhat critical, as too little results in a boring sound, and too much results in an unusable sound. In Dexed and in the DX7, Key Vel scales the programmed Operator output level, so a value of 0 for KeyVel means that the Operator’s output is the programmed Output level. At other KeyVel values, the velocity of the note played has an effect on the output level – scaling it down from the programmed value. Another way to think of this is that the velocity does not add to the output level at all – the most contribution you will get from an Operator is its programmed output level.
The big disruptor (modulator) in this voice is Operator 6, and the EG output of this operator emulates the “filter sweep” in an analog synth. Filter sweeps aren’t sweeps without something moving the filter cutoff in an analog synth – be it envelope, LFO, knob twist, or controller. Our simulated filter sweep is accomplished by reducing the volume of Operator 6 over time, thereby reducing that sine wave volume tuned a fifth higher, which reduces the harmonic content of the resulting audio path – just like programming a filter envelope in an analog synth.
Enjoy and tweak
In addition to adding a little movement through the LFO and PMD parameters, there are a lot of experiments to try with this sound to customize it to your liking.
Recommended tweaks are:
- Adjust the KeyVel levels for Operators 3-6 to adjust the dynamic response to your liking
- Try “rolling off” the response of either Operator 4 or 6 across the keyboard by adjusting the Breakpoint, L Depth and R Depth
- Program differing Coarse tunings to modify the harmonics of Operator 6
- Add some Pitch EG to the overall sound
As we’ve explored the intricacies of the “Swipher” voice in Dexed, we hope this look “Under the Hood” has demonstrated the powerful potential of FM synthesis and inspired you to push the boundaries of your sound design. At SoundEngine, we’re passionate about empowering musicians and producers to create unique, expressive sounds that elevate their music.
Watch for more in-depth articles that demystify Dexed (and other synths) synthesis techniques and unlock new skills as your program. And if you’re ready to expand your palette even further, dive into our curated patch banks for Dexed. Each Dexed Cart is a treasure trove of meticulously crafted sounds waiting to spark your next musical breakthrough. The road trip of sound exploration never ends – let’s continue to push the envelope together!
Resources:
- The Dexed plug-in:
- Our custom programmed Flywheel: Dexed bank:
- Our custom programmed Crankshaft: Dexed bank:
- SoundEngine’s Complete Dexed Owner’s Manual Series:
- FM Synthesis:
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