Why do some synths have the notorious "click" with a static phase sine wave, and some don't?

[chk071]

Hey,

pretty much something i've been trying to wrap my head around since i started messing with soft synths. Why do some synths, like Largo or Spire have a big "click" sound in the attack phase with specific phase settings with a sine wave, and others, like Dune, Electra2 or Diversion simply don't have that? I was under the impression that a sine is a sine. And when you choose the same start phase on every synth, the result, in this case the clicking sound, should be the same. Reality is, it is not. Does anyone know why that is?

[phreaque]

AFAIK, there's an attack smoothing on most of modern vst synths, they just don't give .01 ms.
But it would be nice to post a couple of audio examples to discuss this issue in details.

[ATN69]

I can't explain the exact science behind it since I am not an software engineer but normally you can get rid of that by increasing the attack time ever so slightly.

[chk071]

AFAIK, there's an attack smoothing on most of modern vst synths, they just don't give .01 ms.
But it would be nice to post a couple of audio examples to discuss this issue in details.

Ah, didn't know about that attack smoothing, makes sense. I'll post an audio example.

@ ATN69: I don't want to get rid of the click. I really like it. Wished every synth has it. Give us the click, devs.

Btw, the early Aes Dana albums had a lot of those clicking sine wave sounds, that's probably why i like it.

[ATN69]

AFAIK, there's an attack smoothing on most of modern vst synths, they just don't give .01 ms.
But it would be nice to post a couple of audio examples to discuss this issue in details.

Ah, didn't know about that attack smoothing, makes sense. I'll post an audio example.

@ ATN69: I don't want to get rid of the click. I really like it. Wished every synth has it. Give us the click, devs.

I see..so then add a transient shaper to that and it will be great

[fluffy_little_something]

Since I switched to Hybrid 3, I am rid of that problem because that synth doesn't even make sine waves

Anyway, are you talking about a click or a blip? Low frequency or the high-frequency blip, like when turning on your stereo or speakers vs starting your DAW (when ASIO takes over my audio, I also hear a blip)?
I don't think the click has anything to do with the type of waveform as such. It might also be there with other waveforms, yet harder to hear because the additional signal content hides it. But when you take a saw and turn the lp cutoff frequency down, you might hear it as well.

Some synths also make such sounds when using mono mode, others don't.

When phase matters, you are likely using oscillator reset. And maybe envelope retrigger in addition to that. That is destined to produce that kind of sound.

[chk071]

I made a short demo:

https://soundcloud.com/chk-sound/sine-wave-click-test

4 synths, always playing 4 beats, then 1 beat break, then the next one. The first synth is Largo, 2nd is Spire, 3rd is Electra2, 4th is Dune CM. On all 4 synths, i set the start phase of the sine wave to the highest "amplitude" if you can call it like that, the most clicky start phase position. On Spire, and Electra2, i bypassed the filter section, on Largo and Dune CM, the 24 dB low pass filter was active, but with filter cutoff maximum open. You can hear how Largo's and Spire's sine wave is very clicky, while Electra2's and Dune CM's isn't really clicky. You can sense some clickiness, yes, but not nearly as intense as on the other synths.

Could it have to do with the speed of the envelopes too?

[phreaque]

Well mate, with some of the vsts I have, did a test, and found interesting results.
The click is sounding much louder, when the phase is set to a degree between 20 & 110. Of course I'm using a single oscillator and it is retriggered.

With Sylenth1, I found the sine wave is clicky when the phase is at 75 degree. But honestly with higher pitches, the amplitude of the oscillator is damped a little! That's interesting!

FM7, the sine wave is pure with hard attack but not clicky.

Sytrus!!! This little mofo! It has the best-est click ever! Tried to set the phase value at 60, and it just started to bite!
But the interesting thing, even if you set the attack at most immediate value, the sound will be soften.

Brainstormer, a much better clicky oscillators it offers with good phase control..

Listented to your demo, seems you altered the ADSR a bit, because the sound is somehow plucky.

Setting the phase to something other than 0 degree, will make the waveform to start from a non zero amplitude location, and since the process is digital, so the audio converters will pop a bit to make that sound.

[chk071]

The only thing i did to the envelopes was to adjust them to be the same, and give the sound a bit of release, so it can fade out a little, apart from that, i haven't messed with it at all. Now that you say it though, i left the gate setting in BlueARP which i used for all synths, on the default setting, probably 90%. But that should be the same for all synths too then. Regarding the phase: It's a bit tricky to set that in all synths, because they have different values. And i suspect, even different starting positions for setting the value too. In Spire and Electra2 you have a graphical display for the starting phase position, in the other synths, you have to go by ear. on Largo e.g. the "clicky" position is 90° as one should expect, on Electra2 it seemed to be around a value of 50. In Dune CM, you have positive and negative percentage values, and it seemed, the clicky position is e.g. at 25% plus.

[BlitBit]

Could it have to do with the speed of the envelopes too?

Yes, you can find some further information about the influence of "snappy" envelopes in this post. There I have used a sine with a phase of 90° to test the "snappiness" of the envelopes of different synths.

The click is generated for the following reason. Let's assume that there is no ADSR and that the signal is delivered immediately to your speakers. If you play a sine with 0° phase offset the first sample that will be generated will be a zero which represents your speaker membrane at rest. The next sample is a non-zero value which is still close to zero (let's assume a low frequency sine). It will tell your speaker membrane to move just a bit. The next sample will tell it to move a bit more and so on. Basically, the speaker membrane will have lots of time to move from the neutral position to the outermost position described by the sine (and back...). However, if you start with a phase of 90° the last sample before the sine hits will be a zero (membrane at rest) followed by a rather big first sample value, e.g. 1. So you basically tell your speaker to move very quickly from the resting position to the maximum position.

Please note that such big jumps also occur in saw and square signals which are rich in harmonics. Therefore the start of a sine signal with a phase of 90° will be rich in harmonics, followed by a quick fade to a "boring" sine signal with only one harmonic.

Using sine waves with phase offsets can give some extra bite for synthesized kicks because the transient will be rich in harmonics for the reasons described above.

[chk071]

Awesome, thanks for explaining, and pointing to that thread. It perfectly makes sense to me, as both Largo's and Spire's envelopes, i consider in the quite snappy league, while, at least for Dune CM, i can't really claim that. It's definitely a pleasing character to me, so it's something i try out on every synth, and when it's not there, or, worse, the synth doesn't even feature oscillator reset, it's a bit of a disapointment, because, for me, it's important on certain sounds.

[ENV1]

Do you want recommendations for synths with a good and consistent click?

If so, is this the kind of click youre after? https://1fichier.com/?bj8ajg6pac

(Thats a WAV file.)

[chk071]

Korg Minilogue?

[ENV1]

Korg Minilogue?

Nope, Helix Beta.

(Clicks great, doesnt it.)

[chk071]

Yeah, definitely. Still have a license for Helix here, which unfortunately doesn't get much (or rather, any) use though, as i frankly have too many other synths, and i had some issues with the handling in general.