# Why does getTotalNumInputChannels() always return 2 for VST and VST3

**URL:** <https://forum.juce.com/t/why-does-gettotalnuminputchannels-always-return-2-for-vst-and-vst3/31231>\
**Category:** General JUCE discussion\
**Created:** [January 11, 2019, 7:53pm UTC](https://forum.juce.com/t/why-does-gettotalnuminputchannels-always-return-2-for-vst-and-vst3/31231 "2019-01-11T19:53:17Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![PixelPacker](https://sea2.discourse-cdn.com/flex026/user_avatar/forum.juce.com/pixelpacker/32/9869_2.png) [@PixelPacker](https://forum.juce.com/u/PixelPacker)\
**Post date:** [January 11, 2019, 7:53pm UTC](https://forum.juce.com/t/why-does-gettotalnuminputchannels-always-return-2-for-vst-and-vst3/31231/1 "2019-01-11T19:53:17Z")

</div>

I have a Plug-In that implements:

```
bool SpacealiserAudioProcessor::isBusesLayoutSupported (const BusesLayout& layouts) const
{
    return
        !layouts.getMainInputChannelSet().isDisabled() &&
        layouts.getMainInputChannels() > 0 &&
        layouts.getMainInputChannels() <= 8 &&
        !layouts.getMainOutputChannelSet().isDisabled() &&
        layouts.getMainOutputChannels() == 2
    ;
}

```

i.e. accept everything with two outputs and one to eight inputs.

I observe the following in reaper when I load my plugin onto a 5.1 (i.e. six channels) track:

VST:

- getTotalNumInputChannels() returns 2
- reaper recognises that the plugin supports up to eight inputs: ![image](https://us1.discourse-cdn.com/flex026/uploads/juce/original/2X/e/eb7e75c92782cd49fad12fa526439f6c8837f9e1.png)

VST3:

- getTotalNumInputChannels() returns 2
- plugin is only recognised to support two input channels: ![image](https://us1.discourse-cdn.com/flex026/uploads/juce/original/2X/0/0d9bd889f2711438031a8f428ab8c912ea87a828.png)

AU:

- getTotalNumInputChannels() returns 6
- reaper loads the plugin as 6 inputs / 2 outputs: ![image](https://us1.discourse-cdn.com/flex026/uploads/juce/original/2X/b/b057939b065bac29416cb43bd711099d63330da3.png)

Standalone:

- getTotalNumInputChannels() returns 2
- I can only select a single stereo pair in the default device selector

I want the behaviour of the AU wrapper in all cases. Is this possible? Why do VST / VST3 plugins behave like this? Is this documented somewhere ?

Thanks & best,  
Ben

anyone ?

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**Author:** ![ttg](https://sea2.discourse-cdn.com/flex026/user_avatar/forum.juce.com/ttg/32/14456_2.png) [@ttg](https://forum.juce.com/u/ttg)\
**Post date:** [January 15, 2019, 4:57pm UTC](https://forum.juce.com/t/why-does-gettotalnuminputchannels-always-return-2-for-vst-and-vst3/31231/2 "2019-01-15T16:57:22Z")

</div>

did you try change your constructor to maximum channels as your preferred ?  
in your AudioProcessor

```auto
AudioProcessor (
                BusesProperties()
                .withInput ("Input", AudioChannelSet::stereo())
                .withOutput ("Output", AudioChannelSet::stereo())

```

try other settings than ::stereo , I think it should provide what you’re after.