Er. I did not know that... >.<
I have no idea what a Riivolution is. I guess I've got some googling to do... Unless you'd be so kind as to explain to me what all this mumbo-jumbo is about Riivolution and Geckos and whatnot. :3
EDIT: Ahh. No worries. I think I'm gonna bail on this endeavour. A lot of the stuff I read mentioned running Riivolution from the Homebrew channel... Which I don't have. I know it sounds lazy, but I think I'll forego the hassle and go about my merry way. Thank you very much anyway, though. ^^
Gecko OS is what you've been using to load all of your Brawl hacks from the SD card hencetoforthwith (up until now). It uses ocarina codes to patch files in the game, etc. etc... it makes the mods work. Riivolution is essentially the same sort of program, but is supposedly more versatile and consumes less SD space. HOWEVER, I have yet to get Riivolution to work as well as Gecko OS, because Riivolution takes a lot more user input, as in, you basically have to write the code (XML) for it yourself, although there's a lot of copypasta Riivolution code floating around that works just fine.
My advice is to just stick with the setup you've got and wait for the non-noobs to figure out a more user-friendly way to get sound hacks in the game, because I've been trying for weeks now, and I'm at least a "scrub" by now, and I still can't get sound hacks to work at all. That's MY advice. However, there are obviously some people on these boards who have gotten the damn thing to work, it's just chances are they're a fair bit more versed in programming than either of us...
EDIT: Whoa there hold the phone! How have you been hacking Brawl at all without the Homebrew Channel? Honest to god though, I don't actually know how to do it without Homebrew, you probably just want to get that if you're interested in mods at all...
http://hbc.hackmii.com/