[csgo] Getting odd error for custom sound file

PresidentEvil · **Author**

im trying to use this plugin: http://forums.alliedmods.net/showthread.php?t=202578
which plays a custom sound when you kill someone, idk what game they used when they tested this, but it doesnt work in csgo

custom sound: http://www.mediafire.com/?7h23yiet6cchwwc

directory set up: csgo/sound/death_sound/killnotifysound.mp3

Code:

Downloading http://slayersfastdl.site.nfoservers.com/server/sound/death_sound/killnotifysound.mp3.bz2.
Download finished!
Skipping existing file http://slayersfastdl.site.nfoservers.com/server/sound/death_sound/killnotifysound.mp3.

[Sound] S_StartSound(): Failed to load sound 'death_sound\killnotifysound.mp3'. Can't create mixer.

the [Sound] S_StartSound(): Failed to load sound 'death_sound\killnotifysound.mp3'. Can't create mixer. line prints in console after I kill someone

they told me something is wrong with my server, but other plugins with custom sounds work fine

Im guessing CSGO has different sound functions, can anyone help me?