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SEQUENTIAL/DSI => Prophet => Prophet 12 => Topic started by: WytchCrypt on January 20, 2017, 10:48:18 AM

Title: Cross Fading Between Layers
Post by: WytchCrypt on January 20, 2017, 10:48:18 AM
In the early 90's I had a Yamaha SY22 with a joystick that implemented "Vector Synthesis", or in other words the ability to cross fade between 4 oscillators/PCM sound sources.  The SY series was actually developed from Dave Smith's Prophet VS design...another cool contribution from our esteemed Mr Smith!  Anyway, while I haven't figured out if true 4 sound source vector synthesis is possible on the P12, crossfading between the 2 layers definitely is and is super easy to implement...not to mention a lot of fun to play with 8)

Not sure if this has been documented before because it's pretty basic so apologies if I missed it, but here's a quick way I found to make the layer crossfade happen.  In this example I'll use the mod wheel to control the cross fade, but of course any continuous controller will do.  Here's the necessary settings:

Select Stack Button

Layer A:
1: VCA ENV AMT = 0
2: VCA VEL AMT = 0
3: Mod Matrix Slot:  SRC = Mod Wheel, DEST = AMP ENV AMT, Amount = 127

Layer B:
1: VCA ENV AMT = 127
2: VCA VEL AMT = 0
3: Mod Matrix Slot:  SRC = Mod Wheel, DEST = AMP ENV AMT, Amount = -127

That's it.  Simple.  Zero position of the controller sounds layer B alone then raising the controller crossfades between them up to the 127 position of the controller sounding layer A alone  :D

I also came up with a way to use 2 CC's to crossfade OSC1<->OSC2 and OSC3<->OSC4...but...it's not TRUE 4 voice vector synthesis because there's no way to sound ONLY 1 of the 4 sound sources rather than 2.  Anyway, here's how I implemented that with a couple knobs on my controller set to CC#2 and CC#11.

1: Mod Matrix Slot:  SRC = CC#2, DEST = OSC1LVL, Amount = -127
2: OSC1LVL=127
3: Mod Matrix Slot:  SRC = CC#2, DEST = OSC2LVL, Amount = 127
4: OSC2LVL=0
5: Mod Matrix Slot:  SRC = CC#11, DEST = OSC3LVL, Amount = -127
6: OSC3LVL=127
7: Mod Matrix Slot:  SRC = CC#11, DEST = OSC4LVL, Amount = 127
8: OSC4LVL=0

This is cool, but not nearly as interesting, useful and complex as a way to do true 4 source vector synthesis between complete P12 layers rather than just oscillators within 1 layer.  Perhaps there's a way using multi mode and layers to crossfade between 2 patches and the 2 layers in each but I haven't gotten that far just yet  ;)  Has anyone else experimented with this with success?
Title: Re: Cross Fading Between Layers
Post by: Chaparral on January 21, 2017, 01:59:07 AM
Smart use of the mod wheel (y) I use two stereo volume pedals so I can adjust the layers volumes independently, but it means more gear to move around and extra expense. For me it is worth it as I have maxed out my use of expression controls so that each of my voices is really a wide range of timbres in quadraphonic.
Title: Re: Cross Fading Between Layers
Post by: WytchCrypt on January 21, 2017, 09:48:18 AM
Oh ya, I remember your earlier post about running in quad...very cool  8)

So with 2 stereo volume pedals I'd guess you're using the Main A & B outputs so are able to pan layer A left to speaker 1, layer A right to speaker 2, layer B left to speaker 3, layer B right to speaker 4, then independently control the volumes of layers A & B? 

That must sound amazing to sit in the middle of...especially with a couple pan spread and delay pan modulated layers  ;)
Title: Re: Cross Fading Between Layers
Post by: Chaparral on January 21, 2017, 01:44:47 PM
You guess right. It sounded great in some big ancient churches last year, less so in my tiny music room.

I have got a few voices that I could pan properly in 3 dimensions (with similar layer A and B voices and a tetrahedral speaker arrangement - using a mod controller (with some DC so the zero point is in the middle of the range) for Both Layers  oscs 1+2 (panned R) level up, oscs 3+4 (panned L) level down), but most are just 'double stereo' because I like to have a big range of timbre and the Quad uses 4 pairs of oscillators so any sounds can only use 2 oscillators worth of timbre.
Title: Re: Cross Fading Between Layers
Post by: WytchCrypt on January 23, 2017, 12:06:13 PM
Got it...sounds fantastic.  I sit directly between my speakers in front of the P12 when recording so I get all the fun of experiencing the swirling stereo field.

(https://s-media-cache-ak0.pinimg.com/originals/42/a8/08/42a80807903daa0ad52f2ffddbf84a59.jpg)
Title: Re: Cross Fading Between Layers
Post by: jdt9517 on January 23, 2017, 08:48:55 PM
That's a great technique!  Thanks for the tip.
Title: Re: Cross Fading Between Layers
Post by: WytchCrypt on January 24, 2017, 08:50:59 AM
You're very welcome!  Always glad when someone else can use something I stumbled on  ;)