I am looking an application for a piano teacher. He has to give piano lessons to one student at a time. Currently he does video lessons using the Zoom application, but the Zoom application transmits audio only at 32 kHz (sometimes it drops to 24 kHz), moreover Zoom was created to transmit mainly the human voice not a piano, in fact it has different audio filters to suppress background noise, echo cancellation etc. which cannot be deactivated.
After much research I found the VoiceMeeter application, VoiceMeeter allows to transmit at up to 96 kHz (but more than enough 44.1 kHz), PCM 16/24 bits (16 bits is enough) and with stereo mode (must transmit two microphones) without any audio filter.
The only problem with VoiceMeeter is that it is too complicated to do the connection between student and teacher, both must open UDP ports in their routers/firewalls. If only the teacher does configure the router/firewall it would be perfect, but students often don't have access to these settings.
So is there an application that allows two people to transmit (1 or 2) microphones?