Yes, the number after the dot is for subs. Height speakers like in Dolby Atmos count before the decimal.
However, having said that, this is usually talked about by vendors of equipment. Like 5.1 or 7.2 receivers. It doesn't make a lot of sense/need for the user.
However, having said that, this is usually talked about by vendors of equipment. Like 5.1 or 7.2 receivers. It doesn't make a lot of sense/need for the user.