Hello Everyone.
I have been running a series over on YouTube looking at the different parts of Omnisphere by Spectrasonics. You can view these by heading on over to my channel. We are going to continue our journey through Omnisphere seeing how we can morph and tweak our sounds. In this video it is the turn of the Ring Modulation section. First off lets look at what Ring modulation is. Ring modulation basically involves taking two separate inputted signals, and outputting something new made up of the sum and differences of those signals. To calculate this new output, a ring modulator will typically take the input signal from any instrument and mix it with a second signal generated by an internal oscillator.
In the case of Omnisphere we take our signal from the oscillator in Part A and mix this with the Modulator in the Ring Modulation section. If this screen looks familiar, that's because Ring Modulation shares many similar concepts as Frequency Modulation that we explored in the previous video. 
The difference between the two is that with Ring Modulation the frequencies of both oscillators, the one you selected in the part section and the modulator are multiplied. This in turn changes the overall amplitude of the sound. So, where does the Ring Modulator get the second oscillator from, you've probably guessed, its from the Modulator section here. If we click on the sine wave in this section we get the same oscillators to play with as we do in the the main oscillator page. This means you can blend a deep analogue tone with a harsh, brittle digital tone or something in between.
As per the main oscillator section of Omnisphere we have over 500 waveforms to play with here, so you are not going to run out of ideas anytime soon.
After the modulator section we have tracking which simply enables and disables tracking across the keyboard. This determines whether the Ring Modulator tracks up and down the keyboard as you play. Traditionally, Ring modulators do not track the keyboard, which is part of their character. However, Omnisphere provides this option and allows, for me anyway, a more musical use for your sound.
This doesn't add a lot of musical character on its own and we get a little Dr Who in the sound spectrum. When coupled with a vocoder, which sadly Omnisphere does not have, you get the famous Dalek sound from Dr Who. You know the one that goes "exterminate, exterminate..". You can, however, control this character using the Depth parameter as this determines the interaction between the carrier (our main oscillator from the part) and the modulator (the oscillator that is effecting the sound).
You can hear how we can control the overall effect of the Ring Modulation using just these few parameters. Moving on to the Frequency section. This slider adjusts the amount of overtones that are heard. The higher the value the more you are going to hear. Handily, Spectrasonics have marked out the most useful frequency ratios for us that will provide pleasing results on the ear and keep in tune with the overall sound.
If you want it a less aggressive sound just flick the switch from Boost to Normal and it will subtly adjust your sound this tames things down quite dramatically.
Let's take a look at the Ring Shape parameter which sweeps through the wavetable that we selected in the Modulator section. Depending on what we have selected here can determine what effect the Ring Shape has on our sound. You can go from quite subtle to very dramatic. You can see what the Ring Shape does by looking at the animated graphic in the Modulator Section.
Moving on to Ring Symmetry. this varies the span of the wavetable that we selected in the Modulator section. We can use this parameter to get a Pulse Width Modulation effect, (PWM for short). If we take a saw wave as the modulator and move the Ring Symmetry slider, we can morph from a saw wave to a square wave. Quite a handy little effect that you can add to your sound to provide a little more variety.
Lastly, we come to Ring Sync which is a Hard Sync function that provides a throaty type of characteristic to your sound when swept through its range. Historically you would have had to sacrifice one of your oscillators to provide this type of effect. But handily Omnisphere has you covered and provides a hidden dedicated oscillator. Hard Sync was popularised in the Prophet 5 and early Oberheim Synthesizers and helped provide them with their iconic sounds. Any changes to the sound from this parameter only effects the modulator, it will not effect your main oscillator.
Remember just like the FM section all the sliders on this page can be modulated to provide a more dynamic sound. This is what Ring Modulation can do for your sound.