STILL room to add 4Khz WIDE Lower Side Band audio to totally fill up the available Mumble ELF/ULF/VLF spectrum...
here is a voice test at 19.5Khz LSB 4Khz wide bandwidth
LO-fi, but still readable - 4Khz wide LSB - next to 29 CW signals from
500 hertz to 14.5 Khz ...
OPUS codec audio processing suffers at this high of an audio frequency
when trying to modulate LSB near the upper edge limit of mumble's 20Khz brick wall...
PODCAST AUDIO used to modulate the 19.5 Khz LSB signal is from: