@Five
Hi, if I get you right, you want to be able to control the default audio source so you can switch it from headphones to loud speakers and viceversa simply with a voice command? If so, I'd suggest SoundVolumeView. This is an app that basically gives you full command of all audio devices on your computer. It asigns an ID to each device and even gives you a command line fully executable through TriggerCMD (tested it, use it all the time) to change sistem volume, mute (or unmute) or switch default audio device. Here's an example of wthat the command line to switch default audio device looks like:
"C:\Users\gusta\Downloads\New folder\SoundVolumeView.exe" /SetDefault "{0.0.0.00000000}.{816bd932-8341-4000-9d55-c1652a81396b}" 0
The command live will vary depending on each computer but I hope you get the picture. Must mention that this app works only with physical devices installed on your computer. Will work with loud speakers, even bluetooth, or headphones (wired or BT) but it WILL NOT work with VoiceMeeter (tried it, tested it, didn't work). So if the use of VoiceMeeter is a must for you this won't do. But it might give you one or two ideas. It did to me.
By the way, I'm currently running Win11 64 bits. I know it works well on win10 64 bits too.
Hope this helps, cheers!!