Homebrew How do I make my audio code stereo?

[Northalicious]

Hi! I've been working on making a system for playing audio for my homebrew game and after mixing together various examples and my own binary reading code I have something that works surprisingly solid. I used DSP specifically because it works with Citra (I've been told CSND doesn't work, and from my tests it sadly doesn't). I attached the code below. I figure it's probably a simple change, but I just don't know what to do next to make it output stereo audio instead. Thanks!