Synth Tutorial: Using Two Filters


In this synth tutorial, watch Joe Hanley, the creator of Syntorial, as he demonstrates how and why to use two filters on a synth. Using dual or parallel filters, can give you very detailed control over the shape, body, and weight of your sound. This video is an excerpt from the Z3TA+ 2 Lesson Pack for Syntorial, which contains 37 videos, over 3 hours of footage, and covers every inch of Z3TA+ 2.


In this video, I’m gonna be showing you the many ways in which we could use two filters on a synth and more importantly, how and why you would use two filters.

Now this following video clip is actually an excerpt from the “Z3TA + 2 Lesson Pack for Syntorial,” which has 37 videos that cover every inch of Z3TA + 2 and it’s free for Syntorial users.

Now for those of you who don’t know, Syntorial is a videogame-like training software that teaches you how to program synth patches by ear. It combines a video demonstration with interactive challenges in which you program over 700 patches on a built-in soft synth. The Z3TA + 2 lesson pack adds 37 videos to this that cover Z3TA + 2 and help you transition from the Syntorial synth to Z3TA + 2. If you’d like to try the Syntorial demo, just click the link that’s popping up on the screen now. And if you wanna try a special demo that has some Z3TA + 2 videos included, just click the link that’s popping up now.

Now in the following excerpt, I just finished talking about some filter types, particularly these at the bottom, which I call character filters. Your formants and your resos, which make your synth talk, and your comb, which kinda gives it a trashy, flanging sound. Here we go.

Now, this filter and these talking filters, we can refer to these as character filters. They’re not necessarily there to control your brightness or shade, they’re more to add a distinct sound to your patch. But what if you need to then shape it? Like for example, this comb filter, is pretty bright. What if I want to round it out a bit? That’s where dual comes in.

Select dual and now my sound is running through filter one and then running through filter two. So what I could do is throw a 12 dB low-pass on and now I could take some of the highs off. So it’s great way to take a character filter and then shape it.

Another example would be, let’s say we got a Reso-2 BPF, let me turn this guy off. So let’s say I like that sound but it’s a little too bulky. I can grab a high-pass and just take a little bit of that bottom end off. Again, character shaping.

Now you can also use this dual filter layout for when you want two shaping filters so you can really get fine-tune precise control of your sound. Let’s see, for example, let’s say we got a typical low-pass on the first part.

Let’s say we like our sound, but there’s something in there we don’t like. Well now we can employ a reject filter. So now we get our rounding and we get to cut out that piece that we don’t like. Or another example is, let’s say we’re going for a band-pass filter-like effect, but we need more detailed control over that band-pass. You can kinda make your own. Use an LPF here, a low-pass to cut your highs, and then here, use a high-pass to cut your lows. And now you have individual control over the highs and lows.

And you could even modulate just one of them. So we get that low-pass modulation and keep this bottom chunk off the entire time. Now, you might ask yourself, “If my sound’s going through filter one and then filter two, “what’s the point of this?” Well in reality, what we have here are four filters. This filter one and filter two fader, what it really refers to are what Z3TA calls filter buses.

When we’re in parallel mode, filter one bus just contains filter one. Filter two bus just contains filter two, like you’d expect. In dual mode, filter one bus contains filter one and filter two. Filter two bus contains a copy, that same filter one and same filter two. So what’s the difference? The difference is that filter one bus is controlled with this pan and level. Filter two bus controlled with this pan and this level. These guys are gonna be the same on both buses. But these controls are different.

So this is great if you got multiple oscillators, you want them running through a dual filter setup, but you want one oscillator on the left, and another oscillator on the right, plain and simple. So let’s say we’ve got this sort of band-pass shaping thing going on. And let’s say we got SAW in one oscillator and then we’ve got maybe, I don’t know, let’s try an additive. There we go.

Let’s say I want one on the left and one on the right, well, just like I did with parallel. I route my SAW onto oscillator one, my additive to filter two. And now I have my width. So now I get my dual structure and I get my width.

Now one thing to keep in mind however, some of these filter types don’t play so nice with this spreading when in dual mode. Particularly these talking ones. So you see we kind of lost our width. With these filters we had it, lost it with that. So be mindful of that. With these character filters, some of them, you might lose some of that width.

Now, going back to parallel, let’s initialize. Now we’ve used parallel mode for pretty much the whole time. And we know some basic uses for it, like we just wanna use one filter, we route it to just one filter. Or when we’re using multi-mode, we need to be in parallel mode and then we can decide if we want to have eight voices by being in between and then we can pan them far left and far right. Let’s fix these pan ops here.

However, there’s one other great use and that’s mixing filters. Let me show you an example of that right now. Let’s say we’re going for a talking-like effect here. And I’m gonna modulate this with an envelope.

So we’ve got our basic talking sound here, but one thing I don’t like about it, doesn’t have very much body to it. So, let’s switch over to filter two and use just a simple low-pass. So we got body, voice and now I can mix them together. Without body. So it’s a great way to take two elements of your sound and mix them together. It’s an excellent layering tool.

Another example, let’s take this talking-like effect and route our SAW just to that. And let’s bring in another oscillator, let’s say a square, and we’ll set it down an octave so it’s like a sub-oscillator and route that just to the rounding filter. So now our sub-oscillator isn’t subject to the talking effect. It’s strictly just a nice, round bottom. And our other oscillator gets to do all of the talking. So parallel, when you use this way is an excellent layering tool.

So in summary, with this filter routing, our dual is great for combining a character filter with a shaping filter or to create a really precise shaping filter with the two. While our parallel is great for just a single filter use, multi-use, and a layering use.

And like in the last video, I mentioned that experimentation is a great way to learn about these things, but also really look through the presets and look how they use their filters. Check out how they combine two filters and what it sounds like.

Your task is to create three new patches, utilizing these different filter setups and filter functions and filter types.

All right, well thanks for watching. And just so you know, we got a lot of other free videos like this available on Syntorial’s website. All you gotta do is sign up for our newsletter by clicking the link that’s popping up on your screen now and we’ll send you a link to a page full of videos and articles. Thanks for watching.