Multichannel Routing Device - Automate a CIRCULAR motion?

[rutgermuller]

Hi people.
The new multichannel devices are totally awesome.

I'm already making beautiful motions with max for live devices 'LFO' + 'Multichannel-8 Send Nodes'. These bouncing back and forth motions with compand, smoothing etc. are very useful. But what if I want to make the sound direction (azimuth) spin around, in stead of go back and forth? The LFO only goes up and down, not round.

[Metaphreaq]

Assign it to pan?

[rutgermuller]

Assign it to pan?

How do you mean?

Azimuth = the (surround) panning position.

[rutgermuller]

After some thinking I figured I need an LFO that goes kind of like a sawtooth, that goes from 0% to 100% and then when it hits 100% the next step is 0% again...

actually these figures the saw tooth makes on the Azimuth look much more interesting than a regular circular motion .

But if anyone knows how to make a perfect Azimuth circle with the help of the LFO device or another device, let me know please.

[dataf1ow]

It would be easy to make a device that sent vales to the azimuth number box that went from 0 to 360 in a certain amount of time. Substract from that 180 to get a value between -180 and 180. You could program this to be a toggle that just turns on circular motion. Look into the ambisonics externals for Max/MSP, which is what these devices seem to be based of off.

[rutgermuller]

Thanks, that's helpful. But I'm a lousy programmer, so If anyone wants to make this mod, please share.

[peboer]

I haven't tried them in M4L, but you might want to try the vbap externals
http://cicm.mshparisnord.org/
vbapan~, ambipan~, and, if in 3d, ambicube~
If you don't speak french, don't worry. Click "Telechargements" (which is a way cooler word for "download" anyway), and from there you can get an english version of the page.
Help files are in english and french.
Peter

[rutgermuller]

Thanks.

The newly included Max For Life device 'Multichannel Device with 8 Nodes' is the panner I'm using. Basically I only need a small solution/modification for it to pan in a simple circle. But these CICM patches sure look interesting to look into.

Edit: looked into the externals-patches and I can't find anything about 'automatic panning patterns' like circular motions.

And out of interest: Is the 'Multichannel Device' based on something like VBAP?

[rutgermuller]

I'm now looking at the new Envelope Generator device... sending a straight line from 0 to 180 degrees to the Azimuth. But of course this is too instant.

Maybe something is possible with the envelope generator in combination with the LFO... experts help out!

[ga29]

Helloello, I think what you want to do is really easy, unless I've missed something. You just want to pan your sound round in a simple circle around all the speakers?

First drop a max api ctrl1LFO device on the track and after that drop a multicahnnel-4send nodes devices (or however many nodes you want).

Then, on the max api ctrl1LFO device, set track to "this track", devices to "multicahnnel-4send nodes", parameter to "Azimuth"
and most importantly, set the waveform to saw (the top right of the six possible waveforms) and there you have it. Obviously make sure the distance control is set to something that's not 0.

good luck!

[rutgermuller]

Thanks for the help but like I said I was already messing with the LFO. Problem is that Saw won't cut it... that shape goes in a line up and in a very steep line back down again, not directly to 0. So it won't make a perfect circle.

[ga29]

I seem what you mean, its looks fine until you make the LFO really slow then I can see it jump a little like you said.

My next thought would be to test the following two options

1. modify it to use your own saw wave. if you open the max api ctrl1LFO device then open the patcher LFO at the bottom right are waveform buffers. Double clicking on them should open up a picture showing the waveform. I would have thought the saw should go back from 0. to 1. then the the next sample should be -1.

2. look into the phasor~ object in max. It's a saw wave generator, but suitable for sample accurate timing and control. which might solve the problem of the not so perfect saw wave.

[rutgermuller]

I figured that of course the jitter-factor caused by the downwards slope also depends on the ouput rates of the LFO and the Multichaneller.

But I don't think you can you tweak it in such a way that the random jumping during the downwards slope will never occur.

Of course there's a reason for the downwards slope: preventing audio clicks. But thas's not an issue now right?

So I think saw is not good for circular panning and will look into the patch. Thanks for the tips on that.

Ableton: how do you guys feel about this? Maybe add a button to the LFO to kill the downwards slope of the saw or to draw your own lfo shape?

[ga29]

Ok, figured it out. See in api lfo patch there is a control at the bottom that says 'output rate', as I understand it this sets the rate that the mapped values are updated, so in our case the rate that the lfo values are mapped to the azimuth control. I thought putting it as low as possible would solve it but it didn't. What this means it that there is always some sort of lag between an api devices and the parameter it controls, which usually wouldn't be a problem but in this case it is.

The only way to make it sample accurate is to do it inside the multichannel patch itself with a phasor~.

Anyway, I've figured it out and done it. I took a screen grab but I can't figure out how to post it on the forum. Ha! I can solve max/msp problems, but when it comes to posting a photo.. If you know how to let me know and I'll post the solution up for you.

All the best.

ga

[rutgermuller]

(offtopic: the random function on LFO does nothing or me?)