Chiptune forum

Hello! great atlast a central and working forum :¨) hope everyone will share their precence between here and their irc-caves from now on! warm praise the founders!

I'd like to talk about an effect that mainly uses doubling of onison notes and does not rely on phasing even though it produces a far more elaborate synthesis using ideally 3 channels and similar squarebased waves.

BORING EXPLAINATION
using doubling effects on triangles may be more a challange and more difficult the less symetrical the triangle.
using on sinus is the least effective use to my experience. but it should be said that every wave always favors it's own approach of use and overlap doubling with sinusapproach may likely be possible and successful.
the reason why it's most natural with squares is probably that doubling anything without ramping creates a rampless incline or decline in the.. waveform (sorry suck at terms) which is the characteristic of squares.

the concept is to play a sustaining note (ideally constant volume) and interfere it with another, so they overlap (their waveform cycle should not be in synch (like when triggered simultaneously)).

it needs three channels ideally. two is fine when there's alot of other sound to hide in and four may give extra color or complexity.

MY POINT
the core effect of overlap doubling is the overlapping.. so you want as much of it and as often as you can get.
so.. usually when not having a crazy speed I use delay.

so since it's the same note everytime and constant volume I'll just display note and delay (SDX (X=ticks.. as many as speed(including 0 delay)) in speed 4 (gives me delay 0-3).

note . ..  | note sd1 | note sd3
note sd2 | note sd1 | note . ..
....... ...  | note sd2 | note sd3
note sd1 | note sd3 | ...... . ..
note sd2 | note sd1 | note . ..

and so on.

note displacement is random but ideally never two at the same tick (offset).
all notes are in basic example same pitch.

what this results in isn't a plain sound of a threedoubled sustaining notes. even though there are no cuts in between every redundant note. I mean, maybe you'd think retriggering the note wouldn't make it different from just sustaining it if the retriggered note is the exact same.
the main reason for this is the dutycycle is reset every time you retrigger or play a note since the tempo of the song and the dutycycle probably is not synched up at every row (low chance).
if a tracker could use a random loop-point looping mode this would be really quick :¨)

so what you get here is like a sparkle of retriggers and overlaps.

try it out! check out demonstration I posted on chipforum.net some time ago.

you can hear here that I've added phasing by detune and at the end by vibrato as well. this is not at all essencial to pure overlap doubling but can be added to change the sound just like on simple notes.

IMPORTANT SOME MORE STUFF
another additional method for this technique that comes before adding techniques like phasing or echo/reverb is randomly alternating the sample between closely related squares (or waves if you venture outside of squarebased).

and if you want to alternate the arrangement you can instead of three sparkling channels use one fundamental channel of a sustaining note and then do the retriggering in one or maybe best two other chans.. easier to keep consistent volume this way.

and about the waves you use. by squarebased I mean every wave featuring lowrez stairstep-like rise and fall in wave.. can be a sinelike motion adequetely lowrez.

also even more cool, use squares with overtones (do this by drawing more than one cycle of the same wave and slightly add offset to each cycle.. you'll need more than two.. the more offset, the more coarse the wave.. like 80'ies rave grungy-synths.) __----___----__---____---__ <-like this

and finally use some bloody phasing and even reverb/echo if you dispense extra channels as shamelessly as I do. :¨)

(but maybe you get most chicks by using this on say. gameboy, in lsdj, make third squarewave (with slight overtones?) in pcm-chan)

I hope I only wrote twice as much as I needed. hope it inspires someone and I've not failed to notice everyone already knows this technique and purple motion already gave it a name based on 5 years of academic sound engineering term knowledge. ;¨)

Last edited by nim (2006-02-13 13:20:59)