Hi there, previously I have been able to receive a stereo feed from remote clients - though its been a while since I did this - I couldn't tell you exactly when this was.

In a recent batch of content I had to create, which included musical performances that required stereo, I had no luck.

Audio received was always in mono, no matter what hardware the clients had their end.

Most remote vmixcall attendees were experienced audio people and were sending stereo signals via stereo capable audio interfaces in comprehensive studio setups.
They generally have no issue sending stereo when streaming directly to Youtube/Facebook whatever which would seem to indicate that the browser can handle this.

So I decided to do some testing using a Mac (OS X 10.12.6) and VMIX Call

Using Chrome, I can select the required device, allowing me to mix signals and send via USB interface - but the audio received in VMIX is always mono or summed mono into a stereo signal - hard to tell which.

Using Firefox, I can select the required audio input device (an external USB audio interface) but no matter how many times I set it and tell it to remember, I get no input at all.
Using the internal mic, the audio is very choppy and unusable.

Safari, no matter what I do, setting the USB audio interface as default for both input and output at the system level (safari says it will use the default audio device), the internal mic is always used as the input.

So it seems that somewhere in this there's an issue. The fact that this does not work in three browsers, would suggest there's something in the VMIXCALL WebRTC implementation that has been superseded or broken in browser updates since the last tweak.
I am no expert, but it seems that it may be something to do with the echo cancellation part of WEBRTC which when activated will mono a signal - perhaps this is whats happening if VMIXCALL does not explicitly say what it wants when invoke in the client browser.?

Given the current situation, I wonder if the VMIX people could check this out? it would be very useful to have stereo back in at least one browser on the OSX platform. Many remote musicians will be using OS X as their audio platform and it would make sense for this to be working.

Many thanks

vMix Call is designed for voice and will use the default browser settings which usually include echo cancellation which converts audio to mono.
For stereo you will need to use vMix on both ends.

There are no current plans to update this as using the browser default settings provides the best results for voice which is what vMix Call is primarily designed for.

I realise you wouldn't want to tinker with what works for most in a Vmixcall situation. Would it be viable or possible to have a check box in the VMIX call input setup to say allow for stereo audio - and post a different url that most people wouldn't even see? Maybe put it in the advanced settings that people rarley use to avoid accidental useage.

This would just give an alternative vmixall.com url login page could just disable AEC in the instantiation code?

Then we could use stereo if needed and be more suited to a remote guest with decent audio interfacing capabilities.

Just a thought.