FreeeBSD change default sound card

$ cat /dev/sndstat

# cat /dev/sndstat
Installed devices:
pcm0: <NVIDIA (0x0051) (HDMI/DP 8ch)> (play)
pcm1: <NVIDIA (0x0051) (HDMI/DP 8ch)> (play)
pcm2: <Realtek ALC662 (Analog)> (play/rec) default
pcm3: <Realtek ALC662 (Front Analog Headphones)> (play)
No devices installed from userspace.

 example pcm3

$ sysctl hw.snd.default_unit=3

# sysctl hw.snd.default_unit=3