Quadraphonic G2 patches

Parametex · Joined: Feb 07, 2005 Posts: 9 G2 patch files: 1

Hello good people!

Could any of you kind EM people here point me to G2 patches that utilize its 4 outputs in quadraphonic way. I have arranged my speakers now in a way that I can start experimenting on 4 speaker patches.

Any links, pointers and such would be highly appreciated!

Cheers!

richardnixon · Posted: Sun Mar 26, 2006 8:43 pm Post subject:

I actually haven't come across a patch yet that does this (although I haven't examined every patch on the boards here). It's a very intriguing idea though. A easy place to start would be to check out the "4-voice" patch on page 143 of the G2 manual. Essentially it's a patch that uses the Voice Num. value to create a slight detune for each new voice. You then expand this patch with a 1->8 Multiplexer module that routes to one of the 4 outputs...so not only does each voice have a unique detuning, but each voice will come out a different speaker.

You could obviously get much more sophisticated than this, but it's an easy place to start.

I might have to pickup an extra pair of speakers now Very Happy

Chet · Posted: Mon Mar 27, 2006 6:02 am Post subject:

Here's a patch that, I think, will pan a sound source in a circle around the listener. It has three panel controls: speed, depth, and direction.

I don't have a surround system, so I can't listen to it myself. If it doesn't operate correctly, let me know. The spin sequence is output 1, then 2, then 3, then 4. Depending on how your G2 is connected to your speakers, you may need to swap some outputs to get the right effect.

If it works, you could place two of these after one of Rob's crossovers and make yourself a rotating speaker system.

4Ch-Spinner.pch2

Description:

FX patch for rotating a sound source among the G2's four audio outputs.

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4Ch-Spinner.pch2

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2.43 KB

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cebec · Posted: Mon Mar 27, 2006 8:54 am Post subject:

Nice, I've been thinking about how to do this, too. I have a quadraphonic amp/receiver with a pair of speakers and a pair of event ps6 monitors for the studio. Not sure how I'd set this up for maximum effect...
Anyway, FWIW, there's a couple of 'hidden' quadraphonic utility modules in the G2 editor. Hopefully, they, among others, will see the light of day in a near-future update. Twisted Evil

Thanks for the patch, Chet. I'll try this out, eventually...

mosc · Posted: Fri Mar 31, 2006 9:49 am Post subject:

Chet, this works. Thanks.

There is something I'm trying to do but I can't think of a way to do it. I'd like one knob for rate and direction. The knob would be bipolar. At the center, 0, postion the rotation would stop. Turn it to the right and the rotation would go clockwise; to the left it would go counter clockwise.

I was able to do this on a Kyma system because you can specify a 0 hz oscillator. How can one do this on the G2?

blue hell · Posted: Fri Mar 31, 2006 9:55 am Post subject:

Chet · Posted: Sat Apr 01, 2006 7:45 am Post subject:

Thanks Jan. I never knew the shape LFO could do that. That's a neat trick.

I think this patch works. When the speed drops below zero, the second LFO is triggered by the falling edge of the first LFO, instead of by the rising edge. I had to add the pulse modules because without them there would occasionally be clicks when passing through the zero point.

4Ch-Spinner-2.pch2

Description:

A quadraphonic spinner with a single combined rate and direction control.

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Filename:

4Ch-Spinner-2.pch2

Filesize:

2.53 KB

Downloaded:

1351 Time(s)

mosc · Posted: Sat Apr 01, 2006 9:17 am Post subject:

Excellent. You are a better patcher than me because I was trying to get this to work and couldn't get rid of clicks at the zero speed transision points. Thank you, Chet.

But, in thinking about this, I came to the conclusion that synced LFOs wasn't the best or most general solution. I was thinking what is needed is a quad-panner block that could be fed with any control voltage. In the case of the rotator, it would be fed with a ramp, or sawtooth oscillator.

Here's how it would work:

- one signal in, four signals out; like this circuit
- one CV in for angle:

blue hell · Posted: Sat Apr 01, 2006 11:17 am Post subject:

@ Chet: nice trick to cheaply get the zero crossings OK !

@ Howard: with a bit of extra work on Chet's patch I think this generalizaton might be doable.

Some control circuitry before the final VCA's (for the speaker settings), and a differentiator before the speed control, something like that.

The use of the differentiator would make the LFO's behave like a lookup table - the outputs will freeze on their current value when the input signal is steady.

Alternatively you could use a short expansion (something like three or four terms) of the Taylor series for the sine and cosine functions (see: http://en.wikipedia.org/wiki/Taylor_series for a definition of those)

mosc · Posted: Sat Apr 01, 2006 1:29 pm Post subject:

What's the easiest way to wrap a signal? For example, say you add 16 to a ramp wave. You want the resulting ramp to snap down to -64 when it goes above 64.

blue hell · Posted: Sat Apr 01, 2006 2:08 pm Post subject:

A note quantizer set to quantize to the wanted range (+-64 in your case) and a mixer 2-1B, the one with the invertable inputs. Subtract the quantized input signal from the untreated input signal. I believe this to have some problems around zero as well, but the whole thing could be scaled to work with positive signals only.

blue hell · Posted: Sat Apr 01, 2006 5:35 pm Post subject:

Ehm, and as I was working on finding out about the parameter ranges for LfoShpA ... setting the dir input to zero and resetting the thing should then make the lookup table action possible through the phase input ... maybe Very Happy

Chet · Posted: Sat Apr 01, 2006 7:09 pm Post subject:

Howard, as I read about your generalized panner, I was reminded of two modules that appeared in some early G2 promotional stuff, but never made it into production: a four-channel panner and a four-channel xfader.

Each had two control inputs: one for position, and the other for spread. It's a shame they haven't made it into the editor (yet?).

I don't think I'm going to go further on this. But if I had four speakers, I think I would. I've wondered how good a split bass/horn leslie would sound like if implemented like this.

mosc · Posted: Sat Apr 01, 2006 8:38 pm Post subject:

Yes, too bad we'll probably never see those modules in the G2. I've been working on this generalized panner but haven't got it to work yet. It will take a DSP just for one 4 channel device the way I'm doing it. --sigh--

blue hell · Posted: Sat Apr 01, 2006 9:11 pm Post subject:

try to KISS Exclamation

Earlier today I threw away about 5000 lines out of 12000 of code, it got faster, more flexible and better readable/maintainable.

but it would help a lot to have proper math on that damned synth Very Happy

ehm

cappy2112 · Posted: Sun Mar 11, 2007 1:52 pm Post subject:

blue hell · Posted: Sun Mar 11, 2007 2:02 pm Post subject:

cappy2112 · Posted: Sun Mar 11, 2007 4:00 pm Post subject:

blue hell · Posted: Sun Mar 11, 2007 6:01 pm Post subject: