Spread

sudio · 1 Mar 2012

you have to use multiple oscillators and detune them. typical is the roland super saw approach using 7 slightly detuned saw waves. i.e. take 7 saw osillators and multiply freq input with facors such as e.g. 0.91,0.94,0.97,1,1.03,1.06,1.09. then mix the oscillators together and send them to the filter etc.

Dont know what spread does in case of predator but typically it is something like a) increasing detune factors, b) increase volume of detuned oscillators (no spread => only factor 1.0, full spread => all seven oscillators have roughly similar volume c) spread oscillators in the stereo field.

If there is no sperate "detune" knob it could be a combination of a+b

Search for "Roland Supersaw", and you will find may implementation details and info on that topic. It is pretty easy to implement this in Synthmaker, but it will cost some processor power due to the required large number of oscillators.

a comletely different way may be using a single sound source and applying some kind of pitch shifting to generate multiple detuned copies. This is probably for example imemented in the unisono within the Propellerheads Reason Software. However, it will not sound as good as taking muliple ocillators, i think, but probably lighter on the processor, especially as this can be implemented after all voices have been combined.

CoreStyler · 2 Mar 2012

Tanks really much. i had maybe to read more, infact on predator page it says: Spread function for detuned multiple oscillator sound within one Oscillator. I tried to make that and sounds good, the problem if that when i turn spread on appear one glitches/pops.. Depending on the note, the pops speed amount on the amounting of a note (freq range). Here my design:

I leaved 1st oscillator as normal, then added 6 osc with detune. The detune is added by 0.5->1 multiplied to the ranges you give me.. 0.91..9.93 etc. When spread float < 0.5 the selector cut off the 6 oscillator.. this should save CPU when not running Spread.

I need to find a way to remove pops/glitches. Maybe syncing the osc?

Edit: Should stay <1 to prevent clicks. but.. if i stay under 1 i get clicks on phase near 0 and +/- 1. 😠 dependig on the wave in use.. for example with saw happens, with sine not.

nix · 2 Mar 2012

There is a way to do this using 'MIDI to voices' and 'voices to poly', I can send you a little demo man, if you'd like. It is glitch free, but taxes the appropriate CPU for stacked oscs. I have X6 unison working with it- I like the sound-- classic supersaw

sudio · 2 Mar 2012

You are on a good way. You have to remove the sync completely, as this removes the detuning effect i.e. all oscillators would be synced to the same frequency. This could be also the reason for the clicking bug in your module?! is the clickin in each of the 7 oscillators?

Please take my detuning factors not too serious, they are just a starting value for experimenting. FFT analysis of the original Roland JD 800 supersaw gives roughly 1st pair: f*(1 +/- 0.019) 2nd pair: f*(1 +/- 0.062) 3rd pair: f*(1 +/- 0.108) (info found on the KVR forum) whereas this is maximum detune (of the original Roland supersaw, with detune knob fully turned) and nice sounding values will be significantly smaller. Simply try what sounds best

I am also interested to learn how to do this in 'MIDI to voices' and 'voices to poly', but I am sure you are not be able to combine the voices prior to further processing (filters etc)(nix may proof that I am wrong...). That means using large amount of processing power as everything behind oscillators must be calculated multiple times...However nix version may be an easier solution. So, lets see and learn what nix version brings, perhaps it is suitable for you. My solution is what I think is implemented in synths as the Roland JD 800 or Access Virus. Nix version may be a bit like the NI reaktor unison solution?

If you can't find the clicking issue, then I may genererate an osm providing a working solution (i have to extract that part from one of my synth osm...).

another tip is to start each oscillator with a different randonly generated phase offset, giving a less "digital" sound. Also a common trick in hardware counterparts. If you are interested In that, i can give you more information how to implement that in synthmaker, too

sudio · 2 Mar 2012

btw: this is interesting article on the topic:

http://www.ghostfact.com/jp-8000-supersaw/

CoreStyler · 2 Mar 2012

Tanks. nix pm me. Im actually using a Midi to Voices unison with max 4 voices. Helped me trog last year. We can share the two, so maybe your is more advanced 😉 . The problem should be the attack phase of the waves. When waves like ramp/saw is used, phase should not be near 0 or 1. running a wave like this /, i got these clicks near 0-1. If i turn more like 0.2... this click disappear. Here is at phase 0:

Here at more than 0:

Here 1:

nix · 2 Mar 2012

Actually AFAIK- it's OK to share this. It's the same end result as using multiple oscs, but less messy within a schematic- it was so much easier for me to add this, than going through the multiple oscs method in my big synth project.

billv · 3 Mar 2012

Thanks for sharing this NIx. It sounds unreal, and there's not a dozen Osc's running it. I've had several goes at this and failed. I like the way the Midi to poly has been manipulated. I'm not sure how to hook anything up to it, so there's a good lesson in this OSM for me. I saving this OSM for a rainy day. Wicked.

nix · 3 Mar 2012

Oh 😀 , glad u like it. I hope it was OK to post, not even sure who the original author is, drumma gave it to me. I think it's a nice function for many just checking out SM, and I'd like to generate interest. njoy!

CoreStyler · 4 Mar 2012

Tanks nix. but i want continue to use the way helped me trog because is more fat. but seem really similar. 🙂 Anyway.. i forgot that phase sould stay 0-1 and to invert phase i need to *-1 after osc in synthmaker. I turned knob 0-1 and when i reopened SM, clicks disappear.. Sometimes sm gives strange things. 😮 Clicks appears depending on the wave..and near 0 and 1 phase. Maybe becase there's too big movement from negative to positive. probably theres no way to fix that, without smoothing the output.

Here, the synthesizer (dominus) running one single oscillator (with 7 wavetabe primitives) and 4 voices unison. Kicks made with Hardcore Kicks VSTi 2.. no ohter effects on the track; http://soundcloud.com/thecorestylerz/dominus-unison