-10 to 10 i believe. and if you type in s_volume_voipin_db or what ever the cvar is and press enter it says on my machine that default is 10 now, was -10 originally on my machine.
Hmm maybe it is due to me using the seta command on it.
Isn’t it about 10 p.m. EST right now I am AK time PST +1 right around 5:00 p.m. for me should be on here in a few minutes.

