The classic way of synthesizing woody sounds is to use square wave oscillators. In extension to our cowbell recipe, the relative tuning of two Square waves throws-up many useful, if not entirely natural, woody sounds.

Quick and dirty, first we’ll play around with a single square wave so as to get a flavour of what’s possible and, critically, to set the envelopes correctly.

• Osc 2 Square around D#2 to start. Initially set osc mix to 0/100
• Amp Env amount around 60, decay from about 50 but play with it. This is a good place to add a little peak. For clicky stick sounds, reduce the decay to zero and slowly turn-up the peak. But keep in mind that real-world sounds do not end so abruptly, and are usually accompanied by some decay and/or reverberation.
• 24db LowPass around 60 (just enough to lose the harmonic ‘fizz’), No resonance, No Filter FM. Filter Env decay 40, Env amount 40.
• Go to Modpaths and modulate Amp Envelope Decay with the Amp envelope for a nice curve. There’s a lot of tweaking here – negative values gives more hollow tones, positive values shorten to a click – a sound in itself that has some applications.
• To tighten-up the sound, set the HighPass filter to about 40 or so.
  Now bring-in the Amp Feedback to gives a pretty convincing ‘knock’ to the sound. Usual warning here – used the fixed velocity to set the Amp feedback to provide the heft, but just before ”squeaky’.

Now is the time to start changing Osc2 pitch and to introduce Osc1 as another square wave, playing with their relative pitches and rejoicing at the beauty of our world. Take your time. When you have a good balance between the two levels/pitches, use this nice undocumented feature to tune all oscillators whilst preserving their relative pitches: press and hold the oscillator select button until all four Osc light appear. The Osc Pitch knob will now tune all Oscs simultaneously. Very handy. By this method we open-up even more tonal options. It’s also good to detune the Oscs – even quite extreme detuning has it’s uses here, especially at higher pitches.

• To add some spice, we can Set LFO1 to modulate PWM of either or both oscillators. Plenty of tonal variations here – you should try the full range of LFO frequencies and amount.
• Another LFO trick is to modulate the frequency of one oscillator with a high LFO rate. This also gives a huge variety of interesting tones. For a dullish hit, similar to hitting wet cardboard, try using the Random LFO shape set to Osc2 frequency rate 150, amount 100.
• Filter FM without the resonance makes the sound more flabbly, and effect you might like.

During the process above you have undoubtedly discovered that effective sidestick tones are achievable at higher pitches, whilst at lower pitches we enter usable bass patch territory (remember our Donk?).

The logical extension of this is that our woods can be played chromatically, but these tuned sounds will require extra attention to envelopes and keyboard tracking parameters to maintain a consistent progression up-and-down the keyboard. If you are willing to spend the time here you can make very convincing Marimaba / xylophone type sounds, not to mention everything in-between (which I personally find more interesting).

Using a low 808 conga sample (grabbed from here) as our reference, we see the key frequency is around 150 Hz.

So let’s go straight to…

• Osc 2, triangle wave with Frequency of D2, Osc mix 0/100. Depending on taste, you can tune-up closer to 170Hz (F2), which gives gives a more familiar sound to my ears.
• Use the 12db filter, zero resonance. Slowly close it until you arrive at a tone very close to our example. Just shorten the Amp envelope and you’re 95% of the way there.

But the last 5% is often the hardest part. Although inspection of the waveform reveals no visible attack transients, our example, although typically dullish, somehow seems more ‘slappy’ and definitely has more crisp high frequencies. Our version sounds more tom-ish than it should.

So let’s simulate the initial slap of the conga….

• One possibility is to use FM. I found that putting a sawtooth in Osc 1 with a frequency of 2 octaves above Osc 1 (thus, D4) gives a nice tight snap. We just want a very brief impulse at the start, so use an Aux envelope mapped to FilterFM and set all envelope stages to zero and envelope amount to max – 127. We’ll only use the Peak parameter here (over the screen right-most softknob). Just give it a small amount of peak – anywhere betewn 0 and 5 – whatever brings out the snap but is not overtly heard. We’re really only hearing the envelopes working here – but it’s precisely the effect we want. It’s sounding more like a conga now, eh?
• Another route might be to use a similar abrupt envelope on the filter envelope (which is free because we haven’t used it up to now). However I prefer the FM route and instead apply a small amount of Filter envelope with a fairly fast decay.
• Further, using again the same clicky envelope applied to a noise or percussion sample gives similar results but can lead to nice surprises. But I would reserve noise for other duties.
• Try the various noise sample colours mixed at a low level (<40). This can add a natural, almost reverb-ish quality to the sound. Always worth a tweak. In this case, careful mixing helps to accentuate the snap – helped of course by the Filter and it’s envelope, which must open briefly to hear the impact.
• It’s also good to experiment here with creating exponential (bendable) envelopes – i.e. self-modulating the Amp and Filter envelope decays (as detailed in the manual). This is the ticket for the perfect snap.
• At this stage, will all the effort put into snap, our sound is perhaps a little too clicky – there will be artifacts from the short envelopes. Giving the Amp envelope a little attack – around 6, temporarily gets rid of the artifacts, however they can be re-introduced, but with more control, by adjusting the other envelope attacks slightly to compensate.

Referring back to our sample now, we should be even closer (or not), however we’re still missing the ‘airyness’ of the tail. It just seems brighter and more open. The solution is to modulate the Lowpass filter with another envelope…

• Attach another Aux env to filter cutoff with a moderate amount (35) and decay (40). This will sound too strong, so turn-up the attack until the filter opens more smoothly, adding some brightness to the sound as it dies out.
• At this stage I always close the HighPass filter a little – just enough to cut-out the lowest frequencies whilst retaining the body of the sound. It just makes everything less muddy in the end.
• Although this sound reacts pretty well to chromatic playing – there are some nice marimba-ish sounds at the higher octaves – for a Hi and Mid tome, I would repeat the process above. Apart from the difference in pitch, filter and envelope setting will also vary. For example,  lower congas tend to have a longer Amp envelope, with hi-congas being short and ‘pop’-y. But done once, you’ll have some nice conga templates to experiment with. Layering-in different perc samples and retuning throws-up some great new percussion sounds.

Reverb definitely adds a lot to congas. Essential even.

It’s perhaps no secret, but to get the maximum power out of Tempest, layering the analogue and digital oscillators is the way to go. There will be no silly discussions re: the relative merits of analogue and digital – this time less theory and straight into the mire.

Kicks are a matter of taste and vary widely between different styles. So let’s try building a flexible template that will allow us to go from boomy headbangers to more natural sounding kicks in a few knob tweaks. This is by no means the only approach, but it is one that has brought me satisfaction.

The three components we’ll use:

1. A sub-sine to provide the body of the kick,
2. a kick sample to provide tonal flavour, and
3. the analogue oscillators to provide punch and click.

OK then…

• Starting with an initialised patch, and based on the preceding sub-bass recipe, put a 130Hz sine on Osc 4 and for a start turn it’s pitch all the way down to -24. We’ll come back here to tune our kick…
• In Osc 3 put one of provided Kick samples. To start, try one that has some interesting harmonics (the sample called ‘Nice’ is a good one). But no doubt you will want to try them all at some point, as these provide much of the character of our kick.
• It’s essential now to play with the relative levels of Osc 3 and Osc4 – try to get a nice balance between the two.

Now, this should already sound pretty good and thumpy, without any filter or other settings. Which is handy because we can bypass the filter for the digital Oscs, leaving it free for other tasks.

• So yeah – but all means bypass the filter. I usually set the Pre/Post filter setting at 20/80 so that a little of the signal still goes through the filter. As usual, it’s a matter of taste and experimentation. The cool side-effect of this is that in 16 beats mode, tweaking the filter doesn’t affect our nice low-end. Opens lots of creative opportunities.
• Now let’s look at the Amp envelope. Of course increasing the decay allows more of the sub through. But we can also apply a little ‘Peak’ to give a more upfront sound. Peak is accessed through the rightmost softknob (above the screen) when in envelope mode. Here’s where we should set our primary velocity sensitivity also – v important!
• If the tail is going to be long it needs some animation. Therefore map LFO1 to Osc4 frequency – using a triangle wave to get a wobble going. Personally I like to keep it fast and vibrant – but it can also be tempo-synced; try 8ths or quarters to achieve rhythmic pumping effects. Let’s control it so that the LFO rate slows as the sound decays. First set LFO amount to a reasonable figure (say 60) and turn the Rate all the way to zero. Now go into ModPaths and map Amp Envelope to LFO1 Frequency. As we increase the Mod amount we can hear the effect we want (assuming we have the Amp decay set long enough. As the decay is shortened the wobble effect become less obvious but it definitely contributes to the overall character. And for the better in most cases IMO.
• Staying on the tail, and talking of character, set LFO2 to control All Osc Frequencies and try the Sawtooth (ramp-up) wave. Turn down the rate and set a healthy amount so we can hear our work – say 80. Now slowly turn-up the rate knob. Try various rate/amount settings whilst changing the Amp decay. I find this a great way to make a kick more interesting. Even at extreme settings there are plenty of sweet-sounding variants to surprise and delight. We can even sync this pitch rise to tempo – it can sound pretty cool in a 4/4 pattern when LFO2 sync is set to quarter notes and the Amp decay kept suitably long. Switching to the Reverse Sawtooth (ramp-down) gives us an extra pitch envelope which allows us to add a degree of punch to our digital Oscs. Loads to explore in the LFO’s – you know you want to…
• Now would be a good time to start switching the Kick sample in Osc 3 and re-tuning our Sub in Osc4. As we increase the pitch of our Sub we may also need to adjust LFO1 and it’s control via the Amp envelope.

Ok, moving on to the Analogue oscillators. I’m tending to use these to create the attack and much of the punch. The general principle is to apply several pretty extreme pitch envelopes to Osc frequency. Resulting artefacts – clicks and squeaks – can be hidden behind the sounds of the digital Oscs and controlled to good effect with the filter.

• I always start with Osc 2 with Mix at 0/100. This allows me flexibility to use Filter FM later if I wish (because, as we know, Osc1 is the FM modulator). TBH I haven’t found the Tempest FM very useful for kick-drums (yet) – it seems to impart a hollowing effect, but it’s always nice to have the options.
• However, because we’ve bypassed the filter for the digital oscillators we can, if we wish, use the classic filter kick effect to supplement the samples in Osc 3 and 4. No analogue oscs needed. Therefore, as we have discussed in part 1, use the 4-pole filter, high resonance, low cutoff and use the Filter envelope to simulate the pitch-dropped sine. Lots of variety here. Always a viable option for punchy/squeaky kicks.

For this template I will continue to use Osc2, so open the filter and close the resonance.

• Starting with a triangle, key follow off and wave reset on. Set the frequency at c3. If you’ve done the LFO reverse sawtooth to pitch mapping, you should already hear it’s effect on Osc 2. But it’s a bit weedy. Enter the pitch envelope. Set it to control Osc 2 frequency only and give it a healthy dose – say a decay of 30 and amount of 127. Yes, pretty extreme and you will hear the familiar squeak if you open the filter (but turn down the resonance first!).
• But I’m not stopping there. I also use Aux env 1 to control Osc 2 frequency, again with extreme settings; short decay (20) and full amount (127) for now (but play with this setting). A little trick from the DSI Tempest forums – the envelopes can be delayed – in the aux env1 screen press the right arrow twice and set the delay to 3. This will cause a slight doubling along with a click. This one is a matter of taste but very worthy of exploration (not only for kick drums – it’s also perfect for claps and snares where multiple amp envelopes, slightly delayed, provide a convincing ‘crack’ effect).
• As this will be all very squeaky, it’s time to close the Low Pass filter – just enough to lose the squeak yet retain a little body of Osc2. Now but using the Filter envelope we can control precisely how much of the squeak and click poke through with a decay of 20 and amount of 127 we are in pretty punchy territory.
• Whilst the Low Pass filter settings are critical to getting the right ‘thunk’ and solidity, it is the High-Pass filter that holds most surprises. Just start turning it up. Of course this is filtering only Osc2, but it gives more control over the attack and provides definition and clarity . With reasonable HP filter settings and shorter Amp decay it’s possible to achieve quite natural sounding kicks – however this is also dependent on the sample used in Osc3. A little compression and Bob’s yer uncle.
• Additionally, using the high-pass filter I find makes it safer to use high levels of Amp feedback. This can add some extreme clickiness or ‘knock’ for the hardest of hard kicks. But be very careful here because high Amp feedback + open filter = ouch for you and your equipment. However, judicious balancing of HP filter and Amp feedback alone provides huge variations. This on top of switching the sample in Osc3 and retuning the sub = who says that Tempest has no punch?
• Mapping the sliders to Amp envelope decay, pitch envelopes and the filter gives plenty of sequencing fodder.

OK, enough babbling for now. In Bass drums part 3 we’ll finally make that surdo and try a timpani.

As always, I’m happy to accept corrections, suggestions and reasonable critique.

Analogue purists avert your eyes now. It’s time to look at the digital oscillators.

Logic dictates that having 2 digital-sample oscillators provides us with a massive additional palette of sounds. The on-board samples are pretty good, although they are short. To my ears many of the samples sound highly saturated, evident in a noticeable buzzing. Are these the boosted harmonics? Nobody is telling…

Consider a sine wave. A perfect sine wave contains only one harmonic – the fundamental frequency. Apart from self-resonating filters, analogue sines are not easy to achieve and only a few synthesizers have the option – even then these are not perfect sines. Given the choice, I prefer the perfect sine sample.

Today we will use the 130.81Hz sine sample to make a highly usable sub-bass patch:

• Start with a initialized patch and hunt down this sample to put in Osc 3. Turn it’s pitch down to -24.
• Use ADSR envelopes and set the Amp with an attack and release both at 40, full sustain. The idea is to get just the sub-tone on key-down without any envelope clicks. On key-up the sound should stop fairly abruptly. Set Amp envelope amount to a generous level (64 or so) and turn-down the velocity sensitivity to around 32.
• Leave the Filter wide open with zero resonance. Since sines have no additional harmonics, there is nothing to filter.

This should already be a familiar sound – more ‘felt’ than heard. Alone it sounds unspectacular, but it shines when layered under a kick drum or dropped-in at key moments of your beat. It’s the ticket for copious low-end. Moving-on…

• I like to give a tiny amount of pitch envelope – barely noticeable – to give the attack more interest. Because our amp-attack is set at 40, we need to give our pitch envelope a similar slope, however there are lots of interesting variations to be had with the pitch envelope. For this patch I’ll leave it at Attack of 26, decay 60 and amount 10. These settings are best set while a beat is playing so that the envelopes can follow the groove.
• If you are finding it still a little plain, we can add harmonics with the Feedback control. But again, use the ‘fixed level’ option on pads to prevent unwanted surprises. Another way to add harmonics would be to use FM, that is using Osc1 with a low frequency at Osc mix 0/100).

Of course, playing this chromatically = deep subby basslines.