Fred Fred

I recently started with RNBO, so this might be just a problem with my lack of understanding of the interface between the RNBO internals and the 

 of JavaScript. As I did not find the answer in the docs, I hope you can help me.

I'm using RNBO with JavaScript with the npm package 

. The patcher that I load into the RNBO device has 5 inputs and 9 outputs.

To load the patcher into the device, I follow the 

When I console log the device inputs/outputs and the 

 inputs/outputs, I get the following numbers:

console.log(device.numInputChannels) // --> 5
console.log(device.numOutputChannels) // --> 9
console.log(device.node.numberOfInputs) // --> 5
console.log(device.node.numberOfOutputs) // --> 1

The device numbers are expected, this is what I have defined in Max MSP. The number of inputs on the node is expected as well, but the node has only one output, which is unexpected.

My understanding about the relation between 

 is that the latter provides the interface to the web 

, so I'm trying to connect my other nodes to the 

. But how would I get several outputs from the one single output node?

I suspected that the outputs I am looking for might be on different channels in this single output node, but there are only 2:

console.log(device.node.channelCount) // --> 2

Hey everyone,

I recently started with RNBO, so this might be just a problem with my lack of understanding of the interface between the...

rnbo-device-has-correct-number-of-output-channels-but-its-audionode-only-has-one

you are correct, there is currently no thorough documentation on this and we are currently working on extending the existing one with more details on this.

First off - the way WebAudio handles channels, inputs / outputs and fanning can be a bit confusing and I recommend reading the 

 property doesn't seem to be a reliable simple source of truth when expecting 

 values. You can read more about this in the 

. The behaviour you are witnessing is also not limited to nodes created by RNBO and I can reproduce the behaviour with native WorkletNodes as well.

Now to answer your question about how RNBO exports behave.

 (note that it's deprecated in the standard) there is no concept of multiple inputs / outputs so

 as a source of truth, while keeping the principle of 

"individual inputs, single output with multiple channels"

 in mind. So yes, while it's not totally obvious right away, the numbers you are seeing are basically what is currently expected behaviour.

 works and how the WebAudio API performs mixing things will most likely work the way you expect. If you'd like to target specific output channels of your soundcard we also recommend that your code includes the following:

context.destination.channelCount = context.destination.maxChannelCount;
context.destination.channelCountMode = "explicit";
context.destination.channelInterpretation = "discrete";

If you have further needs to merge and separate channels you can use WebAudio's 

In order to demonstrate all this I've created a small example and made it available 

It basically consists of two exported RNBO patchers:

In the website example the first device is connected to the second using a simple 

cycleDevice.node.connect(passthroughDevice)

 statement. You can then adjust the gain of each channel and select which output channel to listen to, assuming 

Hope that shines some light on this while we continue to extend the RNBO Documentation to cover this more extensively.

thank you so much for your elaborate answer! Even including sample code :-) This helps a lot! I'll look into it.

RNBO Device has correct number of output channels but it's AudioNode only has one