You have to have Riivolution. Gecko won't work so don't even bother trying with it. Make a folder named music in your Brawlmods folder so you have Brawlmods>music. Now take your Smashbros_sound.brsar and put it in the music folder. Then just load Riivolution and it will work with any smash bros hack.
that folder dont work if he is using Gecko OS Setup for Rii
also Brsar is only for US(not PAL)
also wrong place to post you should post in Help