Part of the inspiration behind this blog is the idea that synth sounds can be recreated in a variety of ways. The final project involved reorchestrating classmates' projects. One of my classmates used samples for almost the entire Reason project. I couldn't resist. using Thor and Subtractor, I reconstructed his sampled instruments from scratch. You know what else I did? I saved the patches I created! They might come in handy one day.
This kind of work gets really frustrating really fast when trying to get that EXACT sound when it's really not possible, at least not without some extension of the method being used. For example, I was working on some DX7 strings patches that rely heavily on feedback loops to get an almost analog saw waveform. The original DX7 patches are just gorgeous. But without those feedback loops in Thor, the sound is very nasal and flat sounding. I spent hours trying everythging I could think of to get that sound, even reverting to making three less complex versions of the basic string sound and trying to combine them in different ways to get something more accurate. Nothing worked at all. So after taking something for my headache, I broke down and inserted a PM synth oscillator. I didn't want to! But sometimes you just have to let these things go.
I think a sound designer is better for it, admitting the limitations of a synthesizer or software. At the very least I can say I know what I'm doing!
Let's get on to the patch of the day. Last post was about an FM sound effect. I'm going to continue with that idea with a little trip to the island of Sodor.
That's right, ladies and gentlemen, we're going to build a train using Thor! I'm dedicating this post to my little boy who, being 2 years old, is hopelessly addicted to Thomas the Train videos (thank you, Santa) and is not a happy camper when his half-hour is up. We're also a bit late with potty training, and not even those fits come close to having to forcefully detach the little man from the TV when it's time for Thomas to go night-night!
Now, you don't really have to have a DX7 or FM8 to follow along with these blogs--I see these writings as more like ways to generate ideas for creating sound, maybe even some helpful hints and tricks to creating other kinds of sounds. But if you DO have FM8, it will be easier to follow along. You can also google Dave Benson's DX7 website, which is about as comprehensive as anything else I've ever seen on that synthesizer and related boards/boxes. If you have FM8 but don't have the patches yet, you can find them on Dave's website.
As always, I'm starting out with FM8, and I've got "TRAIN" loaded. By playing a few keys in the middle of the keyboard, I notice that steam engine sound varies with the key that's pressed. I would think you could do the same thing with an amp or filter EG. Even better, you can sync the steam engine sound to song tempo.
Playing lower notes brings in the "choo-choo" whistle. It's exactly the kind of sound you'd expect on a toy or model train set. Playing higher on the keyboard brings in a train bell not unlike what you might hear at a railroad crossing.
So there's a lot going on for one patch. Very complex indeed compared to what we're used to, but there are a few things about this sound we need to pay attention to.
The main thing is there are three completely different timbres going. Pop quiz: How many operators does the DX7 have? 6. Very good. Now, how many distinctive sounds do we hear in TRAIN? 3. OK. Do the math: 3 different sounds/6 operators=1 sound for every 2 operators. This is perfect for Thor because it's the best effective setup we have.
There's the regularity of the steam engine, which will either be controlled by the note, by the LFO, or LFO controlled by keyboard scaling. It's really up to the programmer how this is going to happen. Personally, I like the most rhythmic or cyclical sounds to line up with the song tempo--that's the route I'm going.
Let's take a look at the guts of the patch now that we've done our listening.
By turning off Ops D and F I can hear only the steam component of this sound. Without the distraction of the whistle and the bell, I can fully appreciate what's happening here. In the DX7 world, there's not much difference between a steam engine and a helicopter! As a helicopter, low notes get slow rotor, high notes make a fast rotor. If the rate is dependent on the note played, you might also get some interesting effects playing with pitch bend, or even use MG to increase the rotor speed over a specified period of time. See how easily a variation of this sound could be made to sound like another effect entirely? Let's start with this sound.
We can easily make a broadband white noise effect simply by switching to a noise generator. If we did that, we can also generate the tone created by the FM pair simply by using BPF with high resonance. My attitude is that after letting go with my perfection streak, I don't really care if it gets preserved or not. I also want to stay true to the FM generation of this sound, so I'm sticking with FM pairs in Thors.
I'm going to set Osc 1 exactly the way it is in FM8 with a 5:9 ratio. There are some interesting things here. First, DX7 is using one of those pesky feedback loops, but it gets better: The feedback loop is set all the way to 100. Why is this important? Because this is how the DX7 generates digital noise. Not that I really care, but for the sake of experimentation, I'd like to attempt to preserve the tone present in this sound. Thor was designed for wider, more general application than some of the more specific things that the DX7 does, so FM amount and routing Oscillators to themselves has more extreme effects on the sound than the original DX7. The tone is high pitched as you'd expect with a carrier ratio of 9. Turning the FM amount all the way jup does change the timbre, but it's a brassier sound instead of the subtle whine we're really going for. Even though it doesn't quite work at every level, I'm ok with a FM amount of about 50.
Now for the feedback loop. Again, this isn't an exact science and the results are not what we expect from the DX7. If you've been following this blog, you'll already know how much time I spend in the matrix router. Route Osc1 to Osc1 FM Frequency. I typically test out my sounds low on the keyboard, but what's interesting here is that the upper frequencies aren't as badly affected at low modulation amounts. While holding the note C5, I'm changing the FM amount and the Osc1FM amount in the router. At an FM amount of 18 and router amount of 31, I get a fairly stable tone. Not quite the FM whine I'm going for, but could be nice for some pitched steam effects in another patch. By increasing the router amount to 37, I have some colored wind effects. As I said earlier, I don't really care that much about this kind of sound, so I increase the router amount to 59. There's still a hint of color, but there's definitely a broader spectrum of sidebands than we started with. This is perfect for what we're trying to do.
We need to rhythmically modulate this sound. Load the LPF in filter 1. Move all settings except drive to 0. I want the tempo sync this sound, a slight modification of the original patch. Set LFO1 to Tempo Sync. I'm tempted to use a down-ramp (using a negative value in the router), but I'm afraid that's going to be too hard-sounding. Instead, I'm going to use waveform 8 because I think a triangle wave would be too soft. This also has the advantage that some DC will still get through. A steam engine is always noisy, so it's better not to operate this LFO as an on/off switch. In the router, select LFO1 as source, Filt1Freq as destination, amount 100. Perfect!
Next let's attack the bell/crossing signal. What's interesting about this timbre? Well, it's a seriously inharmonic kind of sound. What else? Every note I play is exactly the same pitch. Enable Osc 2 in Filter 2 and route the signal into the amp. Turn KBD all the way off in the oscillator. What do we notice in FM8? We have a 977.24:371.54 ratio. Harmonic relationships are very important to the Thor synthesizer, even if we don't want/need to use them. So how do we find the relationship between these two frequencies? Quite simply divide the highest number by the lowest because harmonic relationships are always multiples of each other. The result is roughly 2.6, only slightly higher than an octave+3rd. What are some ratios that give similar results? 3:8, 4:11 (interesting), 5:13, 6:15, 6:16, 7:18, 8:20. Any of these can work, of course, but I'm going with 5:13 or, more correctly mod: carrier 13:5. On a side note, I've never understood why FM synthesizers read carrier-modulator. On the DX7 et al, operators read top-bottom, with higher operators in the chain being the modulators and bottom operators the carrier. The signal chain of synthesizers is typically left-right, so why can't the modulator be on the left and the carrier on the right? It would make more sense. Anyway, I've got Oct2, semi 7, and tune 27 (the last two to get closer to the DX7 in pitch, although I'm not going for absolute mathematical precision here). Now, unlike the DX7 patch, I want to make this bell sound periodic, like the steam engine sound. I still want it tempo synced like the steam engine. it should be at a regular steady rate, but at the same time I want it to sound random. And yet I don't want it random like I'm TRYING to sound random... I don't know... Let's do this: Set LFO2 for key sync, tempo sync, waveform 3, rate 3/8. Route LFO2 to Osc2FM amount. Set the osc2 FM amount to 40 and -69 in the router. The illusion of movement would be nice here, so let's do a crescendo/decrescendo using the MG, all synced to tempo. Set Mod Env Tempo Sync, Delay 4/4, Attac k 4/4, Decay 2/1, Release 3/4.
We're about to run into a train-wreck. We still don't have a way to control the whistle blow (it doesn't exist yet, but it will). Using the second filter would be good for the passing-by effect we're going to create. You could also mod filter 2 drive, mixer 1-2 balance, or switch to osc 3 and mod osc 3 level. The only trouble is once those destinations are gone, they're gone, and we may need to use them later.
How about this: Route Osc2 to Amp Input, amount 100, scale with Mod Env, amount 100.
We need to make a whistle now. On the DX7, there's some keyboard scaling that keeps the whistle isolated to the lower part of the keyboard. At the moment, I'm not jsure how to do key scaling for 3 oscillators in Thor, but for now I'm not really all that interested: There's another way to do this. For now we'll concentrate on the basic whistle timbre.
In this case, operators E and F do have a rational relationship even if it is offset to sound inharmonic. The upside is at least the pitch can be altered by pressing different keys. We'll start with the obvious: The ratio is about 3:1.6. Low to high, that's in the neighborhood of a minor 6th above fundamental and octave+5th, so something like a major 7th will get us what we want. Set osc 3 carrier to 13, mod to 24, oct 2, FM amount 18. Enable Osc3 to filter 2.
We want to trigger the whistle any time we want, but not for every single key on the keyboard. By messing around with the filter, I find I can apply a pseudo-keyboard scaling that almost works except for some very unpleasant (and unwanted) high pitches in the sound if I try to trigger the steam engine/warning bell using only high notes. If I lower the cutoff frequency, I also lower the volume level of the whistle sound I want to keep. I've tried various kinds of scaling and nothing seems to work. I'm not sure how to do a proper keyboard scaling or split using Thor, so I'n at a loss as for what to do.
There is another option, however. In the router, select Button 1 (from Modifiers) and route to Osc3 Level. make sure Osc3 Level is all the way down. Go to the global settings and select a note you'd like to use for the train whistle. I chose C3. I also switched the keyboard mode to mono legato so no matter what the other key I press, it won't interrupt the steam engine sound. Since I'll only use a single key for the whistle, there's no real point in setting the oscillator 3 keyboard scale to full. I cut it all the way down and set Oct to 3. This gives the perfect Thomas-style train whistle!
For Filter 2 (where osc3 is going), I set the drive all the way up, all modifiers to 0, cutoff to 3.62 kHz, and res slightly up to 22.
Finally, effects. I try to avoid a lot of effects unless absolutely necessary, like when I run out of oscillators and all FM8 is doing is doubling up on detuned operators. But to get the right kind of CHICKa-chicka sound of a steam locomotive, you really need a touch of delay. I kept this really simple. Time is 78.7 ms, feedback 25, no modulation, and effect level 36.
In conclusion, you can never have enough effects. Even if you aren't good at programming them or all you're interested in are pitched synth sounds and classic kinds of synth effectgs, you'll do well to try some more advanced tricks like this one. TRAIN is a very complex sound for a single instance of a synthesizer, and these kind of sounds are great for coming up with ideas and inspiration for other, similar kinds of sounds.
It's a cool sound to try to make. And my son LOVES it!!!
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