Sinewave from Triangle waveform (explanation)

The sinewave as a result of the Triangle filtered is the most simple Sub to achieve. I talked about the sine waveform in Sinewave, the root of the waves : if you want to know more on it and the benefit of its use – read it (the link will open as a new tab in your browser so you can come back here afterwards).

I will just repeat few things it is the most simple block of sound. It contains only the fundamental note with no harmonics. Sinewave is the start point or part, in a lot of sounds in sound synthesis. It can give extra low energy to a bass guitar, a synth, and it can be layered with a kick drum sample to add weight. The sine can also be a sub bass, part of a bass, it’s the essence of the 808 kick and bass, and it can be made into an organ sound very quickly. Give it movement and it become a Wobble Sub Bass or a Wobble Bass.

No sinewave on the Analog Four

As you know or notice, the Analog Four doesn’t have a sinewave in its waveforms selection, the most close waveform to the sinewave is the triangle waveform, which is fundamental + odd harmonics. So to get close to the sine we are going to filter the odd harmonics to a point where the triangle shape in an oscilloscope look like a sinewave.

For this small exercice you will need a computer and this very nice free plugin from jthorborg.

Available for PC and MAC (for Free)
https://bitbucket.org/Mayae/signalizer/downloads/

The Exercise

1. Set your Analog Four as an external instrument in Ableton Live. We can put a very long midi note sustained don’t hesitate to make it very long so you can experiment with the waveform, signal level, etc. . For the purpose of the exercise I program the D#1 note for 1000 bars… I get the A4 audio back from my soundcard. MIDI Over USB.

Please note I will not explain how to configure all of this you should know how to do that.

2. Init TRK1 or T1 on your Analog Four or you can also Clear Track then reset the filter (F1 frequency to 127,99, Resonance to Zero, F2 in LP2 mode, Frequency to 127,99 and Resonance to Zero) Now on OSC1 set the waveform to TRI (Triangle).

3. Now we’re going to the AMP Page : Attack : 4 – Decay : 64 – Sustain : 100 – Release : 8

Now put the Signalizer VST after the External Instrument plugin from Ableton Live. And by playing the midi D#1 (we are in the LOW END register of the frequencies) you should see something similar to the image below.

4. Now we’re going in the Filter page (FLTR) and we will use the Ladder Filter F1 (the first one) Start to use the FRQ parameter slowly then progressively start filtering the frequency down for the Triangle waveform. You will see after value 60 the waveform will look like more and more like a Sine. The pointed parts of the triangle will round out and give you a wave result like this (For informations here I’m at FRQ 55 :

5. What did you notice in this process ? Anything? If you didn’t notice anything from the exercise then start over again (open the filter completely and start again) keep an eye on your channel level view-meter ! You must notice it even on my screenshot 

6. Feel free to keep an eye again on the channel metering (open up the FRQ filter again to 127,99) and switch from SAW to TRANSISTOR to SQUARE to TRIANGLE (SAW-TRP-PUL-TRI) You will notice (according you get more or less the same gain staging than me) the SAW is around -13,62 dB – TRP is around -15,30 dB – PUL is around -13,16 dB and coming back to our TRI -20dB !

7. Filtering back down with FRQ again our TRI to convert it as a SIN and then the metering should be between -20dB and -46,5 dB depends how much you remove the odd harmonics…

Here I’m at Cutoff 45 (around 50 and 45 thats what i called Perceived Sine it’s usable like this you may at some point in the design bring back some of the odd harmonics regarding level mixing between OSC1 and OSC2…

Here I’m at Cutoff 34 we can see in the spectrum of Signalizer VST we really close to a Pure Sine waveform but the level drop massively

Important!

You must have noticed something during the process and may have pushed your gain staging higher in volume. This is simple and this is very important the result of filtering the triangle is a drop in volume. That’s why it’s extremely difficult to use the Perfect Sinewave in our sound design – we probably haven’t solution to boost it sufficiently. Therefore the Perceived Sinewave may be usable.

What we can do from here

1. Doubling our Filtered Triangle exactly from OSC1 to OSC2 will result in boosting the signal. We must prevent as far as we can phase issue so we’re going into OSC2 page 2 and activate OSC RETRIG (TRG near AM2) Pay attention if the result is what we’re looking for. If we do not double our level we get a recovery around 8 – 10dB which is not bad at all.
2. Using Multimode Filter (F2) as an EQ to boost some Bass frequencies. Feel free to use the Cutoff Point Table and then raise the resonance level a little to boost the area. https://www.elektronauts.com/files/448 
3. Raising the gain staging level to max is not ideal… I prefer to keep everything at 100 to keep some head room
4. Feedback OSC2 in OSC1 ? No it’s an interesting method no doubt but not for that level recovery.
5. Overdrive the Filter ? A little bit of overdrive can help yes but it will introduce hiss/noise on sustained notes so if your goal is a sustained sub-bass, wobble sub-bass I would not use that trick but for short sub bass line, it can work and need a try.
6. Triggering TRK1 (T1) in a Neighbor machine in OSC2 from TRK2 (T2)
   it can help yes but you need to be careful and use a collection of small adjustments like parallel filtering (rather to huge cutoff on TRK1 try medium Cutoff on TRK1 and finished with a small touch on TRK2) with a great set of gain staging you can get a decent sub bass with a comfortable -10dB level meter, But therefore odd harmonics start to bring it back a bit… and you use 2 voices for just a Sub 

Conclusion

I hope i give you some moment and idea to experiment on fundamental & Sinewave in the LOWEND, in the next Article 02 we will look at another way to generate a sinewave a bit more pure and with a bit more of level & dynamics. Which is the Self-Resonating Filter technique.

There’s other ways to get great results in the Low End register and Bass sound design and I will try to cover the most. Somehow you will probably put all the techniques in addition to get what you want… Also, there are all sorts of great compromise in that regards especially with Filter Envelope to get a Perceived Sinewave who fall rapidly to a more pure version of it… etc…

But if like me you love pure sinewave for sub, because you are a club music producer or club/festival performer you might want to choose different synthesizer as an alternative to get a pure sinewave with full gain : Volca FM or Yamaha reface to cover your Sinewave (as Sinewave is the basic material for FM Synthesis), from your Analog Rytm, using Sample from Octatrack, VST inside a DAW, Any Digital Synth like Korg MS2000R – Clavia Nord Lead 4 etc… all give you a pure Sinewave with that dynamic directly from the waveform so you don’t need to find a way to recover the loss of the cutoff process 

The Lowend 101 Patch : UTILBAONE
is based on this technique