HLDJ is an abbreviation that stands for Half Life DJ. It is a source of sounds that you can download and apply on different online games. You can find all sorts of sounds on HLDJ that you can download and apply to all games that you play. When you log on to the website, you are asked if you would like to add these sounds to all your games. You should tick no and add the games where you want to add the sounds. Once sounds have been added, you need to specify the hotkey that will allow you to play these sounds when you play the game. Get HLDJ sound pack here.