NB! It seems this console command is not compatible with CS2.
Command Profile

SND_DZMUSIC_VOLUME

CS:GO

This console command adjusts the volume of the music played when you win a game of Danger Zone (the Battle Royale mode).

Syntax
snd_dzmusic_volume [Volume]

Description

This console command adjusts the volume of the music played when you win a game of Danger Zone (the Battle Royale mode).

Syntax And Arguments

snd_dzmusic_volume [Volume]
Volume The volume you want Danger Zone victory music to play at. The default value for this command is 0.2. Use a larger number to increase the volume, and a smaller number to decrease volume.